ANALOG DEVICES AD9523 Service Manual

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Low Jitter Clock Generator with

14 LVPECL/LVDS/HSTL/29 LVCMOS Outputs

FEATURES

Output frequency: <1 MHz to 1 GHz Start-up frequency accuracy: <±100 ppm (determined by

VCXO reference accuracy)

Zero delay operation

Input-to-output edge timing: <150 ps 14 outputs: configurable LVPECL, LVDS, HSTL, and LVCMOS 14 dedicated output dividers with jitter-free adjustable delay Adjustable delay: 63 resolution steps of ½ period of VCO

output divider Output-to-output skew: <50 ps Duty-cycle correction for odd divider settings Automatic synchronization of all outputs on power-up Absolute output jitter: <200 fs at 122.88 MHz

Integration range: 12 kHz to 20 MHz Distribution phase noise floor: −160 dBc/Hz Digital lock detect Nonvolatile EEPROM stores configuration settings SPI- and I²C-compatible serial control port Dual PLL architecture

PLL1

Low bandwidth for reference input clock cleanup with

external VCXO Phase detector rate of 300 kHz to 75 MHz Redundant reference inputs Auto and manual reference switchover modes

Revertive and nonrevertive switching Loss of reference detection with holdover mode Low noise LVCMOS output from VCXO used for RF/IF

synthesizers

PLL2

Phase detector rate of up to 250 MHz Integrated low noise VCO

APPLICATIONS

LTE and multicarrier GSM base stations Wireless and broadband infrastructure Medical instrumentation Clocking high speed ADCs, DACs, DDSs, DDCs, DUCs, MxFEs Low jitter, low phase noise clock distribution Clock generation and translation for SONET, 10Ge, 10G FC,

and other 10 Gbps protocols Forward error correction (G.710) High performance wireless transceivers ATE and high performance instrumentation

AD9523

FUNCTIONAL BLOCK DIAGRAM

OSC_IN, OSC_IN

REFA, REFA

REFB, REFB

REF_TEST

SCLK/SCL

SDIO/SDA

SDO

PLL1

CONTRO L

INTERFACE

(SPI AND I

EEPROM

PLL2

ZD_IN, ZD_IN

Figure 1.

ZERO

DELAY

GENERAL DESCRIPTION

The AD9523 provides a low power, multi-output, clock distribution function with low jitter performance, along with an on-chip PLL and VCO. The on-chip VCO tunes from 3.6 GHz to 4.0 GHz.

The AD9523 is defined to support the clock requirements for long term evolution (LTE) and multicarrier GSM base station designs. It relies on an external VCXO to provide the reference jitter cleanup to achieve the restrictive low phase noise requirements necessary for acceptable data converter SNR performance.

The input receivers, oscillator, and zero delay receiver provide both single-ended and differential operation. When connected to a recovered system reference clock and a VCXO, the device generates 14 low noise outputs with a range of 1 MHz to 1 GHz, and one dedicated buffered output from the input PLL (PLL1). The frequency and phase of one clock output relative to another clock output can be varied by means of a divider phase select function that serves as a jitter-free coarse timing adjustment in increments that are equal to half the period of the signal coming out of the VCO.

An in-package EEPROM can be programmed through the serial interface to store user-defined register settings for power-up and chip reset.

AD9523

14-CLOCK

DISTRIBUTI ON

OUT0, OUT0

OUT1, OUT1

OUT12, OUT12

OUT13, OUT13

08439-001

Rev. B

Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Anal og Devices for its use, nor for any infringements of patents or ot her rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners.

AD9523

Features.............................................................................................. 1

Applications....................................................................................... 1

Functional Block Diagram .............................................................. 1

General Description ......................................................................... 1

Revision History ............................................................................... 3

Specifications..................................................................................... 4

Conditions..................................................................................... 4

Supply Current.............................................................................. 4

Power Dissipation......................................................................... 5

REFA

REFA, ZD_IN

OSC_CTRL Output Characteristics .......................................... 6

REF_TEST Input Characteristics............................................... 6

PLL1 Output Characteristics ...................................................... 6

Distribution Output Characteristics (OUT0, OUT13,

Timing Alignment Characteristics............................................. 8

Jitter and Noise Characteristics .................................................. 8

PLL2 Characteristics .................................................................... 9

Logic Input Pins—PD, EEPROM_SEL, REF_SEL, SYNC

Status Output Pins—STATUS1, STATUS0 ............................... 9

Serial Control Port—SPI Mode................................................ 10

Serial Control Port—IC Mode................................................ 11

Absolute Maximum Ratings.......................................................... 12

Thermal Resistance .................................................................... 12

ESD Caution................................................................................ 12

Pin Configuration and Function Descriptions........................... 13

Typical Performance Characteristics ........................................... 16

, REFB,

Input Characteristics...................................................... 5

OUT13

.............................................................................................. 9

REFB

, OSC_IN,

) .......................................................................... 7

OSC_IN

, and ZD_IN,

OUT0

RESET

Input/Output Termination Recommendations.......................... 18

Terminology.................................................................................... 19

Theory of Operation ...................................................................... 20

Detailed Block Diagram ............................................................ 20

Overview ..................................................................................... 20

Component Blocks—Input PLL (PLL1).................................. 21

Component Blocks—Output PLL (PLL2) .............................. 22

Clock Distribution ..................................................................... 24

Zero Delay Operation................................................................ 26

Serial Control Port ......................................................................... 27

SPI/IC Port Selection................................................................ 27

IC Serial Port Operation.......................................................... 27

SPI Serial Port Operation.......................................................... 30

SPI Instruction Word (16 Bits)................................................. 31

SPI MSB/LSB First Transfers .................................................... 31

EEPROM Operations..................................................................... 34

Writing to the EEPROM ........................................................... 34

Reading from the EEPROM ..................................................... 34

Programming the EEPROM Buffer Segment......................... 35

Power Dissipation and Thermal Considerations....................... 37

Clock Speed and Driver Mode ................................................. 37

Evaluation of Operating Conditions........................................ 37

Thermally Enhanced Package Mounting Guidelines............ 38

Control Registers............................................................................ 39

Control Register Map ................................................................ 39

Control Register Map Bit Descriptions................................... 44

Outline Dimensions....................................................................... 56

Ordering Guide .......................................................................... 56

Rev. B | Page 2 of 56

AD9523

REVISION HISTORY

3/11—Rev. A to Rev. B

Added Table Summary, Table 8.......................................................7

Cha

o EEPROM Operations Section and Writing to the

nges t

EEPROM Section ............................................................................34

Changes to 0x01A, Bits[4:3], Table 30.......................................... 39

Changes to Bits[4:3], Table 40 .......................................................46

Changes to Table 47, Bit 1 ..............................................................48

11/10—Rev. 0 to Rev. A

Change to General Description....................................................... 1

Changes to Table Summary, Table 1............................................... 3

Change to Input High Voltage and Input Low Voltage Parameters and Added Input Threshold Voltage Parameter,

Table 4................................................................................................. 4

Change to Junction Temperature Rating, Table 16; Changes

to Thermal Resistance Section ......................................................11

Changes to Table 18 ........................................................................12

Added Figure 14, Renumbered Sequentially............................... 16

Edits to Figure 15, Figure 17, and Figure 19................................ 17

Changes to VCO Calibration Section...........................................22

Changed Output Mode Heading to Multimode Output Drivers; Changes to Multimode Output Drivers Section;

Added Figure 26.............................................................................. 23

Added Power Dissipation and Thermal Considerations

Section; Added Table 29, Renumbered Sequentially.................. 35

Changes to Table 34, Table 35, Table 36, and Table 38............... 43

Changes to Address 0x192, Table 50 ............................................ 48

Changes to Table 52 ........................................................................49

Changes to Table 54 ........................................................................50

7/10—Revision 0: Initial Version

Rev. B | Page 3 of 56

AD9523

SPECIFICATIONS

= 122.88 MHz single ended, REFA and REFB on differential at 30.72 MHz, f

VCXO

power mode off, divider phase =1, unless otherwise noted. Typical is given for VDD = 3.3 V ± 5%, and T noted. Minimum and maximum values are given over the full VDD, and T

(−40°C to +85°C) variation, as listed in Tabl e 1.

CONDITIONS

Table 1.

Parameter Min Typ Max Unit Test Conditions/Comments

SUPPLY VOLTAGE

VDD3_PLL1, Supply Voltage for PLL1 3.3 V 3.3 V ± 5% VDD3_PLL2, Supply Voltage for PLL2 3.3 V 3.3 V ± 5% VDD3_REF, Supply Voltage Clock Output Drivers Reference 3.3 V 3.3 V ± 5% VDD1.8_PLL2, Supply Voltage for PLL2 1.8 V 1.8 V ± 5% VDD3_OUT[x:y],1 Supply Voltage Clock Output Drivers 3.3 V 3.3 V ± 5% VDD1.8_OUT[x:y],1 Supply Voltage Clock Dividers 1.8 V 1.8 V ± 5%

TEMPERATURE RANGE, TA −40 +25 +85 °C

x and y are the pair of differential outputs that share the same power supply. For example, VDD3_OUT[0:1] is Supply Voltage Clock Output OUT0,

respectively) and Supply Voltage Clock Output OUT1,

OUT1

(Pin 65 and Pin 64, respectively).

SUPPLY CURRENT

Table 2.

Parameter Min Typ Max Unit Test Conditions/Comments

SUPPLIES OTHER THAN CLOCK OUTPUT DRIVERS

VDD3_PLL1, Supply Voltage for PLL1 22 25.2 mA Decreases by 9 mA typical if REFB is turned off VDD3_PLL2, Supply Voltage for PLL2 67 77.7 mA VDD3_REF, Supply Voltage Clock Output Drivers Reference

LVPECL Mode 5 6 mA

LVDS Mode 4 4.8 mA

HSTL Mode 3 3.6 mA

CMOS Mode 3 3.6 mA

VDD1.8_PLL2, Supply Voltage for PLL2 15 18 mA VDD1.8_OUT[x:y],1 Supply Voltage Clock Dividers2 3.5 4.2 mA Current for each divider: f = 245.76 MHz

CLOCK OUTPUT DRIVERS

LVDS Mode, 7 mA

VDD3_OUT[x:y],1 Supply Voltage Clock Output Drivers 16 17.4 mA f = 61.44 MHz

LVDS Mode, 3.5 mA

VDD3_OUT[x:y],1 Supply Voltage Clock Output Drivers 5 6.2 mA f = 245.76 MHz

LVPECL Mode

VDD3_OUT[x:y],1 Supply Voltage Clock Output Drivers 17 18.9 mA f = 122.88 MHz

HSTL Mode, 16 mA

VDD3_OUT[x:y],1 Supply Voltage Clock Output Drivers 21 24.0 mA f = 122.88 MHz

HSTL Mode, 8 mA

VDD3_OUT[x:y],1 Supply Voltage Clock Output Drivers 14 16.3 mA f = 122.88 MHz

CMOS Mode (Single-Ended)

VDD3_OUT[x:y],1 Supply Voltage Clock Output Drivers 2 2.4 mA f = 15.36 MHz, 10 pF Load

x and y are the pair of differential outputs that share the same power supply. For example, VDD3_OUT[0:1] is Supply Voltage Clock Output OUT0,

respectively) and Supply Voltage Clock Output OUT1,

The current for Pin 63 (VDD1.8_OUT[0:3]) is 2× that of the other VDD1.8_OUT[x:y] pairs.

OUT1

(Pin 65 and Pin 64, respectively).

Rev. B | Page 4 of 56

= 3932.16 MHz, doubler is off, channel control low

VCO

A = 25°C, unless otherwise

OUT0

(Pin 68 and Pin 67,

Only one output driver turned on; for each additional output that is turned on, the current increments by 1.2 mA maximum

Values are independent of the number of outputs turned on

OUT0

(Pin 68 and Pin 67,

AD9523

POWER DISSIPATION

Table 3.

Parameter Min Typ Max Unit Test Conditions/Comments

POWER DISSIPATION Does not include power dissipated in termination resistors

Typical Configuration 891

1047. 1

PD, Power-Down

101 132.2 mW

INCREMENTAL POWER DISSIPATION

Low Power Typical Configuration 367 428.4 mW

Output Distribution, Driver On Incremental power increase (OUT1) from low power typical

LVDS 15.3 18.4 mW Single 3.5 mA LVDS output at 245.76 MHz

47.8 55.4 mW Single 7 mA LVDS output at 61.44 MHz LVPECL 50.1 54.9 mW Single LVPECL output at 122.88 MHz

HSTL 40.2 46.3 mW Single 8 mA HSTL output at 122.88 MHz

43.7 50.3 mW Single 16 mA HSTL output at 122.88 MHz

CMOS 6.6 7.9 mW Single 3.3 V CMOS output at 15.36 MHz

9.9 11.9 mW Dual complementary 3.3 V CMOS output at 122.88 MHz

9.9 11.9 mW Dual in-phase 3.3 V CMOS output at 122.88 MHz

REFA, REFA, REFB, REFB, OSC_IN, OSC_IN, AND ZD_IN, ZD_IN INPUT CHARACTERISTICS

Clock distribution outputs running as follows: seven LVPECL outputs at 122.88 MHz, three LVDS outputs (3.5 mA) at 61.44 MHz, three LVDS outputs (3.5 mA) at 245.76 MHz, one CMOS 10 pF load at

122.88 MHz, and one differential input reference at 30.72 MHz; f

= 122.88 MHz, f

VCXO

= 3932.16 MHz; PLL2 BW = 530 kHz,

VCO

doubler is off PD pin pulled low, with typical configuration conditions

Absolute total power with clock distribution; one LVPECL output running at 122.88 MHz; one differential input reference at

30.72 MHz; f

= 122.88 MHz, f

VCXO

= 3932.16 MHz; doubler is off

VCO

Table 4.

Parameter Min Typ Max Unit Test Conditions/Comments

DIFFERENTIAL MODE

Input Frequency Range 400 MHz Input Slew Rate (OSC_IN) 400 V/µs Minimum limit imposed for jitter performance Common-Mode Internally

0.6 0.7 0.8 V

Generated Input Voltage

Input Common-Mode Range 1.025 1.475 V For dc-coupled LVDS (maximum swing) Differential Input Voltage,

Sensitivity Frequency < 250 MHz

100 mV p-p

Capacitive coupling required; can accommodate single-ended input by ac grounding of unused input; the instantaneous voltage on either pin must not exceed the 1.8 V dc supply rails

Differential Input Voltage,

Sensitivity Frequency > 250 MHz

200 mV p-p

Capacitive coupling required; can accommodate single-ended input by ac grounding of unused input; the instantaneous voltage

on either pin must not exceed the 1.8 V dc supply rails Differential Input Resistance 4.8 kΩ Differential Input Capacitance 1 pF Duty Cycle Duty cycle bounds are set by pulse width high and pulse width low

Pulse Width Low 1 ns Pulse Width High 1 ns

CMOS MODE SINGLE-ENDED INPUT

Input Frequency Range 250 MHz Input High Voltage 1.62 V Input Low Voltage 0.52 V Input Threshold Voltage 1.0 V

When ac coupling to the input receiver, the user must dc bias the

input to 1 V; the singl-ended CMOS input is 3.3 V compatible Input Capacitance 1 pF Duty Cycle Duty cycle bounds are set by pulse width high and pulse width low

Pulse Width Low 1.6 ns Pulse Width High 1.6 ns

Rev. B | Page 5 of 56

AD9523

OSC_CTRL OUTPUT CHARACTERISTICS

Table 5.

Parameter Min Typ Max Unit Test Conditions/Comments

OUTPUT VOLTAGE

High VDD3_PLL1 − 0.15 V R Low 150 mV

REF_TEST INPUT CHARACTERISTICS

Table 6.

Parameter Min Typ Max Unit Test Conditions/Comments

REF_TEST INPUT

Input Frequency Range 250 MHz Input High Voltage 2.0 V Input Low Voltage 0.8 V

PLL1 OUTPUT CHARACTERISTICS

Table 7.

Parameter1 Min Typ Max Unit Test Conditions/Comments

MAXIMUM OUTPUT FREQUENCY 250 MHz

Rise/Fall Time (20% to 80%) 387 665 ps 15 pF load Duty Cycle 45 50 55 % f = 250 MHz

OUTPUT VOLTAGE HIGH Output driver static

VDD3_PLL1 − 0.25 V Load current = 10 mA VDD3_PLL1 − 0.1 V Load current = 1 mA

OUTPUT VOLTAGE LOW Output driver static

0.2 V Load current = 10 mA

0.1 V Load current = 1 mA

CMOS driver strength = strong (see Table 51).

LOAD

> 20 kΩ

Rev. B | Page 6 of 56

AD9523

DISTRIBUTION OUTPUT CHARACTERISTICS (OUT0, OUT0 TO OUT13, OUT13)

Duty cycle performance is specified with the invert divider bit set to 1, and the divider phase bits set to 0.5. (For example, for Channel 0, 0x190[7] = 1 and 0x192[7:2] = 1.)

Table 8.

Parameter Min Typ Max Unit Test Conditions/Comments

LVPECL MODE

Maximum Output Frequency 1 GHz Minimum VCO/maximum dividers Rise Time/Fall Time (20% to 80%) 117 147 ps 100 Ω termination across output pair Duty Cycle 47 50 52 % f < 500 MHz 43 48 52 % f = 500 MHz to 800 MHz 40 49 54 % f = 800 MHz to 1 GHz Differential Output Voltage Magnitude 643 775 924 mV Voltage across pins, output driver static Common-Mode Output Voltage VDD – 1.5 VDD − 1.4 VDD − 1.25 V Output driver static

SCALED HSTL MODE, 16 mA

Maximum Output Frequency 1 GHz Minimum VCO/maximum dividers Rise Time/Fall Time (20% to 80%) 112 141 ps 100 Ω termination across output pair Duty Cycle 47 50 52 % f < 500 MHz 44 48 51 % f = 500 MHz to 800 MHz 40 49 54 % f = 800 MHz to 1 GHz Differential Output Voltage Magnitude 1.3 1.6 1.7 V

Supply Sensitivity 0.6

Common-Mode Output Voltage VDD − 1.76 VDD − 1.6 VDD − 1.42 V

LVDS MODE, 3.5 mA

Maximum Output Frequency 1 GHz Rise Time/Fall Time (20% to 80%) 138 161 ps 100 Ω termination across output pair Duty Cycle 48 51 53 % f < 500 MHz 43 49 53 % f = 500 MHz to 800 MHz 41 49 55 % f = 800 MHz to 1 GHz Differential Output Voltage Magnitude

Balanced 247 454 mV Voltage across pins; output driver static Unbalanced 50 mV

Common-Mode Output Voltage 1.125 1.375 V Output driver static Common-Mode Difference 50 mV

Short-Circuit Output Current 3.5 24 mA Output driver static

CMOS MODE

Maximum Output Frequency 250 MHz Rise Time/Fall Time (20% to 80%) 387 665 ps 15 pF load Duty Cycle 45 50 55 % f = 250 MHz Output Voltage High Output driver static

VDD − 0.25 V Load current = 10 mA VDD − 0.1 V Load current = 1 mA

Output Voltage Low Output driver static

0.2 V Load current = 10 mA

0.1 V Load current = 1 mA

mV/ mV

Voltage across pins, output driver static; nominal supply

Change in output swing vs. VDD3_OUT[x:y]

/∆VDD3)

(∆V

Absolute difference between voltage magnitude of normal pin and inverted pin

Voltage difference between output pins; output driver static

Rev. B | Page 7 of 56

AD9523

TIMING ALIGNMENT CHARACTERISTICS

Table 9.

Parameter Min Typ Max Unit Test Conditions/Comments

OUTPUT TIMING SKEW

Between Outputs in Same Group1

LVPECL, HSTL, and LVDS

Between LVPECL, HSTL, and LVDS

30 183 ps

Outputs

CMOS

Between CMOS Outputs 100 300 ps Single-ended true phase high-Z mode Mean Delta Between Groups1 50 Adjustable Delay 0 63 Steps Resolution step; for example, 8 × 0.5/1 GHz

Resolution Step 500 ps ½ period of 1 GHz

Zero Delay

Between Input Clock Edge on REFA or

150 500 ps REFB to ZD_IN Input Clock Edge, External Zero Delay Mode

There are three groups of outputs. They are as follows: the top outputs group: OUT0, OUT1, OUT2, OUT3; the right outputs group: OUT4, OUT5, OUT6, OUT7, OUT8,

OUT9; and the bottom outputs group: OUT10, OUT11, OUT12, OUT13.

Delay off on all outputs; maximum deviation between rising edges of outputs; all outputs are on, unless otherwise noted

PLL1 settings: PFD = 7.68 MHz, ICP = 63.5 µA, R

= 10 kΩ,

ZERO

antibacklash pulse width is at maximum, BW = 40 Hz, REFA and ZD_IN are set to differential mode

JITTER AND NOISE CHARACTERISTICS

Table 10.

Parameter Min Typ Max Unit Test Conditions/Comments

OUTPUT ABSOLUTE RMS TIME JITTER

LVPECL Mode, HSTL Mode, LVDS Mode 125 fs Integrated BW = 200 kHz to 5 MHz 136 fs Integrated BW = 200 kHz to 10 MHz 169 fs Integrated BW = 12 kHz to 20 MHz 212 fs Integrated BW = 10 kHz to 61 MHz 223 fs Integrated BW = 1 kHz to 61 MHz

Application example based on a typical setup (see Table 3); f = 122.88 MHz

Rev. B | Page 8 of 56

AD9523

PLL2 CHARACTERISTICS

Table 11.

Parameter Min Typ Max Unit Test Conditions/Comments

VCO (ON CHIP)

Frequency Range 3600 4000 MHz Gain 45 MHz/V

PLL2 FIGURE OF MERIT (FOM) −226 dBc/Hz MAXIMUM PFD FREQUENCY

Antibacklash Pulse Width

Minimum and Low 250 MHz Maximum and High 125 MHz

LOGIC INPUT PINS—PD, EEPROM_SEL, REF_SEL, RESET, SYNC

Table 12.

Parameter Min Typ Max Unit Test Conditions/Comments

VOLTAGE

Input High 2.0 V Input Low 0.8 V

INPUT LOW CURRENT ±80 ±250 µA

CAPACITANCE 3 pF RESET TIMING

Pulse Width Low 50 ns Inactive to Start of Register Programming 100 ns

SYNC TIMING

Pulse Width Low 1.5 ns High speed clock is CLK input signal

The minus sign indicates that, due to the internal pull-up resistor, current is flowing out of the AD9523

STATUS OUTPUT PINS—STATUS1, STATUS0

Table 13.

Parameter Min Typ Max Unit Test Conditions/Comments

VOLTAGE

Output High 2.94 V Output Low 0.4 V

Rev. B | Page 9 of 56

AD9523

SERIAL CONTROL PORT—SPI MODE

Table 14.

Parameter Min Typ Max Unit Test Conditions/Comments

CS (INPUT)

Voltage

Input Logic 1 2.0 V Input Logic 0 0.8 V

Current

Input Logic 1 30 µA Input Logic 0 −110 µA

Input Capacitance 2 pF

SCLK (INPUT) IN SPI MODE

Voltage

Input Logic 1 2.0 V Input Logic 0 0.8 V

Current

Input Logic 1 240 µA Input Logic 0 1 µA

Input Capacitance 2 pF

SDIO (WHEN INPUT IS IN BIDIRECTIONAL MODE)

Voltage

Input Logic 1 2.0 V Input Logic 0 0.8 V

Current

Input Logic 1 1 µA Input Logic 0 1 µA

Input Capacitance 2 pF

SDIO, SDO (OUTPUTS)

Output Logic 1 Voltage 2.7 V Output Logic 0 Voltage 0.4 V

TIMING

Clock Rate (SCLK, 1/t Pulse Width High, t Pulse Width Low, t

) 25 MHz

SCLK

8 ns

HIGH

12 ns

LOW

SDIO to SCLK Setup, tDS 3.3 ns SCLK to SDIO Hold, tDH 0 ns SCLK to Valid SDIO and SDO, tDV 14 ns CS to SCLK Setup, tS CS to SCLK Setup and Hold, tS, tC

CS Minimum Pulse Width High, t

PWH

CS has an internal 40 kΩ pull-up resistor

The minus sign indicates that, due to the internal pull-up resistor, current is flowing out of the AD9523

SCLK has an internal 40 kΩ pull-down resistor in SPI mode but not in I

10 ns 0 ns 6 ns

C mode

Rev. B | Page 10 of 56

AD9523

SERIAL CONTROL PORT—I²C MODE

VDD = VDD3_REF, unless otherwise noted.

Table 15.

Parameter Min Typ Max Unit Test Conditions/Comments

SDA, SCL (WHEN INPUTTING DATA)

Input Logic 1 Voltage 0.7 × VDD V Input Logic 0 Voltage 0.3 × VDD V Input Current with an Input Voltage Between

0.1 × VDD and 0.9 × VDD Hysteresis of Schmitt Trigger Inputs 0.015 × VDD V Pulse Width of Spikes That Must Be

Suppressed by the Input Filter, t

SPIKE

SDA (WHEN OUTPUTTING DATA)

Output Logic 0 Voltage at 3 mA Sink Current 0.4 V Output Fall Time from VIH

MIN

to VIL

MAX

with

a Bus Capacitance from 10 pF to 400 pF

TIMING

Clock Rate (SCL, f

) 400 kHz

I2C

Bus Free Time Between a Stop and Start

Condition, t

IDLE

Setup Time for a Repeated Start Condition,

SET; STR

Hold Time (Repeated) Start Condition, t

Setup Time for Stop Condition, t Low Period of the SCL Clock, t High Period of the SCL Clock, t SCL, SDA Rise Time, t SCL, SDA Fall Time, t Data Setup Time, t Data Hold Time, t

20 + 0.1 C

RISE

20 + 0.1 C

FAL L

100 ns

SET; DAT

100 880 ns

HLD; DAT

Capacitive Load for Each Bus Line, C

CB is the capacitance of one bus line in picofarads (pF).

According to the original I2C specification, an I2C master must also provide a minimum hold time of 300 ns for the SDA signal to bridge the undefined region of the SCL

falling edge.

HLD; STR

0.6 µs

SET; STP

1.3 µs

LOW

0.6 µs

HIGH

400 pF

−10 +10 µA

50 ns

20 + 0.1 C

250 ns

Note that all I VIH

MIN

1.3 µs

0.6 µs

After this period, the first clock pulse is generated

300 ns

This is a minor deviation from the original I²C specification of 0 ns minimum2

C timing values are referred to

(0.3 × VDD) and VIL

levels (0.7 × VDD)

MAX

Rev. B | Page 11 of 56

AD9523

ABSOLUTE MAXIMUM RATINGS

Table 16.

Parameter Rating

VDD3_PLL1, VDD3_PLL2, VDD3_REF,

−0.3 V to +3.6 V

VDD3_OUT, LDO_VCO to GND REFA, REFA, REFIN, REFB, REFB to GND SCLK/SCL, SDIO/SDA, SDO, CS to GND OUT0, OUT0, OUT1, OUT1, OUT2, OUT2,

OUT3, OUT3

, OUT4, OUT4, OUT5, OUT5,

−0.3 V to +3.6 V

OUT6, OUT6, OUT7, OUT7, OUT8, OUT8,

OUT9, OUT9

, OUT10, OUT10, OUT11, OUT11, OUT12, OUT12, OUT13, OUT13 to GND

SYNC, RESET, PD to GND

−0.3 V to +3.6 V STATUS0, STATUS1 to GND −0.3 V to +3.6 V SP0, SP1, EEPROM_SEL to GND −0.3 V to +3.6 V VDD1.8_PLL2, VDD1.8_OUT, LDO_PLL1,

2 V

LDO_PLL2 to GND Junction Temperature1 115°C Storage Temperature Range −65°C to +150°C Lead Temperature (10 sec) 300°C

See Table 17 for θJA.

Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

THERMAL RESISTANCE

θJA is specified for the worst-case conditions, that is, a device soldered in a circuit board for surface-mount packages.

Table 17. Thermal Resistance

Package Type

72-Lead LFCSP,

10 mm × 10 mm

Per JEDEC 51-7, plus JEDEC 51-5 2S2P test board.

Per JEDEC JESD51-2 (still air) or JEDEC JESD51-6 (moving air).

Per MIL-Std 883, Method 1012.1.

Per JEDEC JESD51-8 (still air).

For information about power dissipation, refer to the Power Dissipation and Thermal Considerations section.

ESD CAUTION

Airflow Velocity (m/sec) θ

1, 2

1, 3

1, 4

1, 2

Unit

0 21.3 1.7 12.6 0.1 °C/W

1.0 20.1 0.2 °C/W

2.5 18.1 0.3 °C/W

Rev. B | Page 12 of 56

AD9523

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

PLL1_OUT

ZD_IN

VDD1.8_PLL2

OUT0

VDD3_OUT[0:1]

OUT1

VDD1.8_OUT[0: 3]

OUT2

VDD3_OUT[2:3]

OUT3

EEPROM_SEL

STATUS0/SP0

STATUS1/SP1

7271706968676665646362616059585756

LDO_PLL1

VDD3_PLL1

LF1_EXT _CAP

OSC_CTRL

LF2_EXT _CAP

LDO_PLL2

VDD3_PLL2

LDO_VCO

REF_SE L

NOTES

1. THE EXPOSED PADDLE IS THE GROUND CONNECTION ON THE CHIP. IT MUST BE SOLDERED TO THE ANALOG GRO UND OF THE PCB TO ENSURE PROPER FUNCTI ONALITY

AND HEAT DISSIPATION, NOISE, AND MECHANICA L STRENGTH BENEFITS.

REFA REFA REFB REFB

OSC_IN OSC_IN

1 2 3 4 5 6 7 8 9

11 12 13 14 15 16

17SYNC

18VDD3_REF

PIN 1 INDICATOR

192021222324252627282930313233

SDO

RESET

SDIO/SDA

SCLK/SCL

REF_TEST

AD9523

(TOP VIEW)

OUT13

OUT12

VDD3_OUT[12:13]

VDD1.8_OUT[ 4:5]

OUT4

VDD3_OUT[4:5]

OUT5

VDD1.8_OUT[ 6:7]

OUT6

VDD3_OUT[6:7]

OUT7

VDD1.8_OUT[ 8:9]

OUT8

VDD3_OUT[8:9]

OUT9

35OUT10

36VDD1.8_OUT[10:11]

OUT11

OUT12

VDD1.8_OUT[ 12:13]

OUT10

VDD3_OUT[10: 11]

08439-002

Figure 2. Pin Configuration

Table 18. Pin Function Descriptions

Pin No.

Mnemonic Type

1 LDO_PLL1 P/O

Description

1.8 V Internal LDO Regulator Decoupling Pin for PLL1. Connect a 0.47 µF decoupling capacitor from this pin to ground. Note that, for best performance, the LDO bypass capacitor must be placed in

close proximity to the device. 2 VDD3_PLL1 P 3.3 V Supply PLL1. Use the same supply as VCXO. 3 REFA I

Reference Clock Input A. Along with REFA

, this pin is the differential input for the PLL reference.

Alternatively, this pin can be programmed as a single-ended 3.3 V CMOS input. 4

REFA

Complementary Reference Clock Input A. Along with REFA, this pin is the differential input for the

PLL reference. Alternatively, this pin can be programmed as a single-ended 3.3V CMOS input. 5 REFB I

Reference Clock Input B. Along with REFB

, this pin is the differential input for the PLL reference.

Alternatively, this pin can be programmed as a single-ended 3.3 V CMOS input. 6

REFB

Complementary Reference Clock Input B. Along with REFB, this pin is the differential input for the PLL

reference. Alternatively, this pin can be programmed as a single-ended 3.3 V CMOS input. 7 LF1_EXT_CAP O PLL1 External Loop Filter Capacitor. Connect this pin to ground. 8 OSC_CTRL O Oscillator Control Voltage. Connect this pin to the voltage control pin of the external oscillator. 9 OSC_IN I

PLL1 Oscillator Input. Along with OSC_IN

, this pin is the differential input for the PLL reference.

Alternatively, this pin can be programmed as a single-ended 3.3 V CMOS input. 10

OSC_IN

Complementary PLL1 Oscillator Input. Along with OSC_IN, this pin is the differential input for the PLL

reference. Alternatively, this pin can be programmed as a single-ended 3.3 V CMOS input. 11 LF2_EXT_CAP O PLL2 External Loop Filter Capacitor Connection. Connect capacitor to this pin and the LDO_VCO pin. 12 LDO_PLL2 P/O

LDO Decoupling Pin for PLL2 1.8 V Internal Regulator. Connect a 0.47 F decoupling capacitor from

this pin to ground. Note that for best performance, the LDO bypass capacitor must be placed in close

proximity to the device. 13 VDD3_PLL2 P 3.3 V Supply for PLL2.

Rev. B | Page 13 of 56

AD9523

Pin No. Mnemonic Type

14 LDO_VCO P/O

PD 16 REF_SEL I Reference Input Select. This pin has an internal 40 kΩ pull-down resistor. 17

SYNC

18 VDD3_REF P 3.3 V Supply for Output Clock Drivers Reference. 19

RESET

CS 21 SCLK/SCL I

22 SDIO/SDA I/O Serial Control Port Bidirectional Serial Data In/Data Out for SPI Mode (SDIO) or I²C Mode (SDA). 23 SDO O

24 REF_TEST I Test Input to PLL1 Phase Detector. 25

OUT13

26 OUT13 O

27 VDD3_OUT[12:13] P 3.3 V Supply for Output 12 and Output 13 Clock Drivers. 28

OUT12

29 OUT12 O

30 VDD1.8_OUT[12:13] P 1.8 V Supply for Output 12 and Output 13 Clock Dividers. 31

OUT11

32 OUT11 O

33 VDD3_OUT[10:11] P 3.3 V Supply for Output 10 and Output 11 Clock Drivers. 34

OUT10

35 OUT10 O

36 VDD1.8_OUT[10:11] P 1.8 V Supply for Output 10 and Output 11 Clock Dividers. 37

OUT9

38 OUT9 O

39 VDD3_OUT[8:9] P 3.3 V Supply for Output 8 and Output 9 Clock Drivers. 40

OUT8

41 OUT8 O

42 VDD1.8_OUT[8:9] P 1.8 V Supply for Output 8 and Output 9 Clock Dividers. 43

OUT7

44 OUT7 O

45 VDD3_OUT[6:7] P 3.3 V Supply for Output 6 and Supply Output 7 Clock Drivers. 46

OUT6

47 OUT6 O

Description

2.5 V LDO Internal Regulator Decoupling Pin for VCO. Connect a 0.47 µF decoupling capacitor from this pin to ground. Note that, for best performance, the LDO bypass capacitor must be placed in close proximity to the device.

I Chip Power-Down, Active Low. This pin has an internal 40 kΩ pull-up resistor.

Manual Synchronization. This pin initiates a manual synchronization and has an internal 40 kΩ pull-up resistor.

Digital Input, Active Low. Resets internal logic to default states. This pin has an internal 40 kΩ pull-up resistor.

I Serial Control Port Chip Select, Active Low. This pin has an internal 40 kΩ pull-up resistor.

Serial Control Port Clock Signal for SPI Mode (SCLK) or I

C Mode (SCL). Data clock for serial program-

ming. This pin has an internal 40 kΩ pull-down resistor in SPI mode but is high impedance in I²C mode.

Serial Data Output. Use this pin to read data in 4-wire mode (high impedance in 3-wire mode). There is no internal pull-up/pull-down resistor on this pin.

Complementary Square Wave Clocking Output 13. This pin can be configured as one side of a differential LVPECL/LVDS/HSTL output or as a single-ended CMOS output.

Square Wave Clocking Output 13. This pin can be configured as one side of a differential LVPECL/ LVDS/HSTL output or as a single-ended CMOS output.

Complementary Square Wave Clocking Output 12. This pin can be configured as one side of a differential LVPECL/LVDS/HSTL output or as a single-ended CMOS output.

Square Wave Clocking Output 12. This pin can be configured as one side of a differential LVPECL/ LVDS/HSTL output or as a single-ended CMOS output.

Complementary Square Wave Clocking Output 11. This pin can be configured as one side of a differential LVPECL/LVDS/HSTL output or as a single-ended CMOS output.

Square Wave Clocking Output 11. This pin can be configured as one side of a differential LVPECL/ LVDS/HSTL output or as a single-ended CMOS output.

Complementary Square Wave Clocking Output 10. This pin can be configured as one side of a differential LVPECL/LVDS/HSTL output or as a single-ended CMOS output.

Square Wave Clocking Output 10. This pin can be configured as one side of a differential LVPECL/ LVDS/HSTL output or as a single-ended CMOS output.

Complementary Square Wave Clocking Output 9. This pin can be configured as one side of a differential LVPECL/LVDS/HSTL output or as a single-ended CMOS output.

Square Wave Clocking Output 9. This pin can be configured as one side of a differential LVPECL/ LVDS/HSTL output or as a single-ended CMOS output.

Complementary Square Wave Clocking Output 8. This pin can be configured as one side of a differential LVPECL/LVDS/HSTL output or as a single-ended CMOS output.

Square Wave Clocking Output 8. This pin can be configured as one side of a differential LVPECL/ LVDS/HSTL output or as a single-ended CMOS output.

Complementary Square Wave Clocking Output 7. This pin can be configured as one side of a differential LVPECL/LVDS/HSTL output or as a single-ended CMOS output.

Square Wave Clocking Output 7. This pin can be configured as one side of a differential LVPECL/ LVDS/HSTL output or as a single-ended CMOS output.

Complementary Square Wave Clocking Output 6. This pin can be configured as one side of a differential LVPECL/LVDS/HSTL output or as a single-ended CMOS output.

Square Wave Clocking Output 6. This pin can be configured as one side of a differential LVPECL/ LVDS/HSTL output or as a single-ended CMOS output.

Rev. B | Page 14 of 56

AD9523

Pin No. Mnemonic Type

48 VDD1.8_OUT[6:7] P 1.8 V Supply for Output 6 and Output 7 Clock Dividers. 49

OUT5

50 OUT5 O

51 VDD3_OUT[4:5] P 3.3 V Supply for Output 4 and Output 5 Clock Drivers. 52

OUT4

53 OUT4 O

54 VDD1.8_OUT[4:5] P 1.8 V Supply for Output 4 and Output 5 Clock Dividers. 55 STATUS1/SP1 I/O

56 STATUS0/SP0 I/O

57 EEPROM_SEL I

OUT3

59 OUT3 O

60 VDD3_OUT[2:3] P 3.3 V Supply for Output 2 and Output 3 Clock Drivers. 61

OUT2

62 OUT2 O

63 VDD1.8_OUT[0:3] P 1.8 V Supply for Output 0, Output 1, Output 2, and Output 3 Clock Dividers. 64

OUT1

65 OUT1 O

66 VDD3_OUT[0:1] P 3.3 V Supply for Output 0 and Output 1 Clock Drivers. 67

OUT0

68 OUT0 O

69 VDD1.8_PLL2 P 1.8 V Supply for PLL2. 70 ZD_IN I

ZD_IN

72 PLL1_OUT O

EP EP, GND GND

P = power, I = input, O = output, I/O = input/output, P/O = power/output, GND = ground.

Description

Complementary Square Wave Clocking Output 5. This pin can be configured as one side of a differential LVPECL/LVDS/HSTL output or as a single-ended CMOS output.

Square Wave Clocking Output 5. This pin can be configured as one side of a differential LVPECL/ LVDS/HSTL output or as a single-ended CMOS output.

Complementary Square Wave Clocking Output 4. This pin can be configured as one side of a differential LVPECL/LVDS/HSTL output or as a single-ended CMOS output.

Square Wave Clocking Output 4. This pin can be configured as one side of a differential LVPECL/ LVDS/HSTL output or as a single-ended CMOS output.

Lock Detect and Other Status Signals (STATUS1)/I down resistor.

Lock Detect and Other Status Signals (STATUS0)/I down resistor.

EEPROM Select. Setting this pin high selects the register values stored in the internal EEPROM to be loaded at reset and/or power-up. Setting this pin low causes the AD9523 to load the hard-coded default register values at power-up/reset. This pin has an internal 40 kΩ pull-down resistor.

Complementary Square Wave Clocking Output 3. This pin can be configured as one side of a differential LVPECL/LVDS/HSTL output or as a single-ended CMOS output.

Square Wave Clocking Output 3. This pin can be configured as one side of a differential LVPECL/ LVDS/HSTL output or as a single-ended CMOS output.

Complementary Square Wave Clocking Output 2. This pin can be configured as one side of a differential LVPECL/LVDS/HSTL output or as a single-ended CMOS output.

Square Wave Clocking Output 2. This pin can be configured as one side of a differential LVPECL/ LVDS/HSTL output or as a single-ended CMOS output.

Complementary Square Wave Clocking Output 1. This pin can be configured as one side of a differential LVPECL/LVDS/HSTL output or as a single-ended CMOS output.

Square Wave Clocking Output 1. This pin can be configured as one side of a differential LVPECL/ LVDS/HSTL output or as a single-ended CMOS output.

Complementary Square Wave Clocking Output 0. This pin can be configured as one side of a differential LVPECL/LVDS/HSTL output or as a single-ended CMOS output.

Square Wave Clocking Output 0. This pin can be configured as one side of a differential LVPECL/ LVDS/HSTL output or as a single-ended CMOS output.

External Zero Delay Clock Input. Along with ZD_IN reference. Alternatively, this pin can be programmed as a single-ended 3.3 V CMOS input.

Complementary External Zero Delay Clock Input. Along with ZD_IN, this pin is the differential input for the PLL reference. Alternatively, this pin can be programmed as a single-ended 3.3 V CMOS input.

Single-Ended CMOS Output from PLL1. This pin has settings for weak and strong in Register 0x1BA, Bit 4 (see Table 51).

Exposed Paddle. The exposed paddle is the ground connection on the chip. It must be soldered to the analog ground of the PCB to ensure proper functionality and heat dissipation, noise, and mechanical strength benefits.

C Address (SP1). This pin has an internal 40 kΩ pull-

C Address (SP0). This pin has an internal 40 kΩ pull-

, this pin is the differential input for the PLL

Rev. B | Page 15 of 56

AD9523

TYPICAL PERFORMANCE CHARACTERISTICS

= 122.88 MHz, REFA differential at 30.72 MHz, f

VCXO

CURRENT (mA)

HSTL = 16mA

HSTL = 8mA

= 3686.4 MHz, and doubler is off, unless otherwise noted.

VCO

CURRENT (mA)

20pF

10pF

2pF

0 200 400 600 800 1000 1200

FREQUENCY ( MHz)

08439-003

Figure 3. VDD3_OUT[x:y] Current (Typical) vs. Frequency;

HSTL Mode, 16 mA and 8 mA

CURRENT (mA)

0 200 400 600 800 1000 1200

LVD S = 7 mA

LVDS = 3.5mA

08439-004

FREQUENCY ( MHz)

Figure 4. VDD3_OUT[x:y] Current (Typical) vs. Frequency;

LVDS Mode, 7 mA and 3.5 mA

CURRENT (mA)

0 200 400 600 800 1000 1200

FREQUENCY ( MHz)

08439-005

Figure 5. VDD3_OUT[x:y] Current (Typical) vs. Frequency, LVPECL Mode

0 100 200 300 400 500 600

FREQUENCY ( MHz)

08439-006

Figure 6. VDD3_OUT[x:y] Current (Typical) vs. Frequency;

CMOS Mode, 20 pF, 10 pF, and 2 pF Load

3.5

3.0

2.5

2.0

L SWING (V p-p)

1.5

1.0

DIFFERENTI

0.5

0 200 400 600 800 1000 1200

HSTL = 16mA

HSTL = 8mA

FREQUENCY ( MHz)

08439-007

Figure 7. Differential Voltage Swing vs. Frequency;

HSTL Mode, 16 mA and 8 mA

1.6

1.4

1.2

1.0

0.8

0.6

0.4

DIFFERENTIAL SWING (V p-p)

0.2

0 200 400 600 800 1000 1200

FREQUENCY (MHz)

08439-008

Figure 8. Differential Voltage Swing vs. Frequency,

LVPECL Mode

Rev. B | Page 16 of 56

AD9523

–

1.4

1.2

LVD S = 7 m A

1.0

0.8

L SWING (V p-p )

0.6

LVD S = 3 . 5m A

0.4

DIFFERENTI

0.2

0 200 400 600 800 1000 1200

FREQUENCY ( MHz)

Figure 9. Differential Voltage Swing vs. Frequency;

LVDS Mode, 7 mA and 3.5 mA

08439-009

–80

–90

–100

–110

–120

–130

–140

PHASE NOISE (dBc/Hz)

–150

–160

–170

100 1k 10k 100k 1M 10M

NOISE: ANALYSIS RANG E X: BAND M ARKER ANALYSIS RANG E Y: BAND M ARKER INTG NOISE: –75.94595dBc/39.99MHz

RMS NOISE: 225.539µRAD

12.9224mdeg RMS JITTER: 194.746fsec RESIDUAL FM: 2.81623kHz

1: 100Hz, –85.0688dBc/Hz 2: 1kHz, –113.3955dBc/Hz 3: 8kHz, –125.8719dBc/Hz 4: 16kHz, –129.5942dBc/Hz 5: 100kHz, –134.5017dBc/Hz 6: 1MHz, –145.2872dBc/Hz 7: 10MHz, –156.2706dBc/Hz 8: 40MHz, –157.4153dBc/Hz x: START 12kHz

CENTER 40.006MHz SPAN 79.988MHz

FREQUENCY (Hz)

Figure 12. Phase Noise, Output = 184.32 MHz

(VCXO = 122.88 MHz, Crystek VCXO CVHD-950)

STOP 80MHz

08439-015

4.0

3.5

3.0

2.5

2pF

10pF

20pF

2.0

1.5

AMPLITUDE (V)

1.0

0.5

0 100 200 300 400 500 600

FREQUENCY ( MHz)

Figure 10. Amplitude vs. Frequency and Capacitive Load;

CMOS Mode, 2 pF, 10 pF, and 20 pF

–80

–90

–100

–110

–120

–130

–140

PHASE NOISE (dBc/Hz)

–150

–160

08439-010

–170

100 1k 10k 100k 1M 10M

NOISE: ANALYSIS RANG E X: BAND M ARKER ANALYSIS RANG E Y: BAND M ARKER INTG NOISE: –78.8099dBc/39.99MHz

RMS NOISE: 162.189µRAD

9.29276mdeg RMS JITTER: 210.069fsec RESIDUAL FM: 2.27638kHz

FREQUENCY (Hz)

1: 100Hz, –89.0260dBc/Hz 2: 1kHz, –116.9949dBc/Hz 3: 8kHz, –129.5198dBc/Hz 4: 16kHz, –133.3916dBc/Hz 5: 100kHz, –137.7680dBc/Hz 6: 1MHz, –148.3519dBc/Hz 7: 10MHz, –158.3307dBc/Hz 8: 40MHz, 159.1629–dBc/Hz x: START 12kHz

STOP 80MHz CENTER 40.006MHz SPAN 79.988MHz

08439-016

Figure 13. Phase Noise, Output = 122.88 MHz

(VCXO = 122.88 MHz, Crystek VCXO CVHD-950; Doubler Is Off)

CH1 200mV 2.5ns/DI V

40.0GS/s

A CH1 104mV

Figure 11. Output Waveform (Differential), LVPECL at 122.88 MHz

08439-013

CH1 500mV Ω 2.5ns/DIV

40.0GS/s

A CH1 80mV

08439-049

Figure 14. Output Waveform (Differential), HSTL at 16 mA, 122.88 MHz

Rev. B | Page 17 of 56

AD9523

INPUT/OUTPUT TERMINATION RECOMMENDATIONS

AD9523

LVD S

OUTPUT

0.1µF

100Ω

0.1µF

HIGH

IMPEDANCE

INPUT

DOWNSTREAM

Figure 15. AC-Coupled LVDS Output Driver

AD9523

LVD S

OUTPUT

100Ω

HIGH

IMPEDANCE

INPUT

DOWNSTREAM

Figure 16. DC-Coupled LVDS Output Driver

AD9523

LVPECL-

COMPATIBLE

OUTPUT

0.1µF

100Ω

0.1µF

HIGH

IMPEDANCE

INPUT

DOWNSTREAM

Figure 17. AC-Coupled LVPECL Output Driver

DEVICE

AD9523

HSTL

OUTPUT

08439-142

0.1µF

100Ω

0.1µF

HIGH

IMPEDANCE

INPUT

DOWNSTRE AM

DEVICE

08439-046

Figure 19. AC-Coupled HSTL Output Driver

AD9523

HSTL

OUTPUT

08439-143

100Ω

HIGH

IMPEDANCE

INPUT

DOWNSTREAM

DEVICE

08439-047

Figure 20. DC-Coupled HSTL Output Driver

AD9523

0.1µF

SELF-BIASED

REF, VCXO,

ZERO DEL AY

INPUTS

08439-048

100Ω

(OPTIONAL

08439-044

)

RESISTOR VALUE DEPENDS UPON

REQUIRED TERMINATION OF S OURCE.

Figure 21. REF, VCXO, and Zero Delay Input Differential Mode

AD9523

LVPECL

COMPATIBLE

OUTPUT

100Ω

HIGH

IMPEDANCE

INPUT

DOWNSTREAM

DEVICE

08439-045

Figure 18. DC-Coupled LVPECL Output Driver

Rev. B | Page 18 of 56

AD9523

TERMINOLOGY

Phase Jitter and Phase Noise

An ideal sine wave can be thought of as having a continuous and even progression of phase with time from 0° to 360° for each cycle. Actual signals, however, display a certain amount of variation from ideal phase progression over time. This phenomenon is called phase jitter. Although many causes can contribute to phase jitter, one major cause is random noise, which is characterized statistically as being Gaussian (normal) in distribution.

This phase jitter leads to a spreading out of the energy of the sine wave in the frequency domain, producing a continuous power spectrum. This power spectrum is usually reported as a series of values whose units are dBc/Hz at a given offset in frequency from the sine wave (carrier). The value is a ratio (expressed in decibels) of the power contained within a 1 Hz bandwidth with respect to the power at the carrier frequency. For each measurement, the offset from the carrier frequency is also given.

It is meaningful to integrate the total power contained within some interval of offset frequencies (for example, 10 kHz to 10 MHz). This is called the integrated phase noise over that frequency offset interval and can be readily related to the time jitter due to the phase noise within that offset frequency interval.

Phase noise has a detrimental effect on the performance of ADCs, DACs, and RF mixers. It lowers the achievable dynamic range of the converters and mixers, although they are affected in somewhat different ways.

Time Jitter

Phase noise is a frequency domain phenomenon. In the time domain, the same effect is exhibited as time jitter. When observing a sine wave, the time of successive zero crossings varies. In a square

wave, the time jitter is a displacement of the edges from their ideal (regular) times of occurrence. In both cases, the variations in timing from the ideal are the time jitter. Because these variations are random in nature, the time jitter is specified in seconds root mean square (rms) or 1 sigma (Σ) of the Gaussian distribution.

Time jitter that occurs on a sampling clock for a DAC or an ADC decreases the signal-to-noise ratio (SNR) and dynamic range of the converter. A sampling clock with the lowest possible jitter provides the highest performance from a given converter.

Additive Phase Noise

Additive phase noise is the amount of phase noise that can be attributed to the device or subsystem being measured. The phase noise of any external oscillators or clock sources is subtracted. This makes it possible to predict the degree to which the device impacts the total system phase noise when used in conjunction with the various oscillators and clock sources, each of which contributes its own phase noise to the total. In many cases, the phase noise of one element dominates the system phase noise. When there are multiple contributors to phase noise, the total is the square root of the sum of squares of the individual contributors.

Additive Time Jitter

Additive time jitter is the amount of time jitter that can be attributed to the device or subsystem being measured. The time jitter of any external oscillators or clock sources is subtracted. This makes it possible to predict the degree to which the device impacts the total system time jitter when used in conjunction with the various oscillators and clock sources, each of which contributes its own time jitter to the total. In many cases, the time jitter of the external oscillators and clock sources dominates the system time jitter.

Rev. B | Page 19 of 56

AD9523

THEORY OF OPERATION

DETAILED BLOCK DIAGRAM

VCXO

STATUS0/

VDD3_PLL1

LDO_PLL1 LDO_VCO

OSC_CTRL OSC_IN

PLL1_OUT

SP0

STATUS1/

SP1

LF2_EXT_CAPLF1_EXT_CAP

VDD1.8_O UT[x:y]

VDD3_OUT[ x:y]

REFA

REF_SEL

REFB REFB

REF_TEST

SDIO/SDA

SDO

SCLK/SCL

RESET

EEPROM_SEL

÷R

SWITCH-

OVER

CONTROL

÷R

CONTROL

INTERFACE

(SDI AND I

EEPROM

÷N1

LOCK

DETECT

P F D

LOOP

FILTER

CHARGE

PUMP

PLL1

AD9523

LDO_PLL2

Figure 22. Top Level Diagram

OVERVIEW

The AD9523 is a clock generator that employs integer-N-based phase-locked loops (PLL). The device architecture consists of two cascaded PLL stages. The first stage, PLL1, consists of an integer division PLL that uses an external voltage-controlled crystal oscillator (VCXO) from 15 MHz to 250 MHz. PLL1 has a narrow-loop bandwidth that provides initial jitter cleanup of the input reference signal. The second stage, PLL2, is a frequency multiplying PLL that translates the first stage output frequency to a range of 3.6 GHz to 4.0 GHz. PLL2 incorporates an integerbased feedback divider that enables integer frequency multiplication. Programmable integer dividers (1 to 1024) follow PLL2, establishing a final output frequency of 1 GHz or less.

The AD9523 includes reference signal processing blocks that enable a smooth switching transition between two reference inputs. This circuitry automatically detects the presence of the reference input signals. If only one input is present, the device uses it as the active reference. If both are present, one becomes the active reference and the other becomes the backup reference. If the active reference fails, the circuitry automatically switches to the backup reference (if available), making it the new active reference. A register setting determines what action to take

Rev. B | Page 20 of 56

÷D1

×2

STATUS MO NITOR

LOCK DETECT/

SERIAL PORT

ADDRESS

LOCK

DETECT

CHARGE

PUMP

÷N2

VDD3_PLL2 VDD1.8_PLL2

LOOP

FILTER

VCO

SYNC

SIGNAL

÷M1

PLL2

TO SYNC

SYNC

∆t

÷D

EDGE

∆t

÷D

EDGE

∆t

÷D

EDGE

∆t

÷D

EDGE

∆t

÷D

EDGE

∆t

÷D

EDGE

∆t

÷D

EDGE

∆t

÷D

EDGE

∆t

÷D

EDGE

∆t

÷D

EDGE

∆t

÷D

EDGE

∆t

÷D

EDGE

∆t

÷D

EDGE

∆t

÷D

EDGE

OUT13 OUT13 OUT12 OUT12 OUT11 OUT11 OUT10 OUT10 OUT9 OUT9 OUT8 OUT8 OUT7 OUT7 OUT6 OUT6 OUT5 OUT5 OUT4 OUT4

OUT3 OUT3

OUT2 OUT2

OUT1 OUT1

OUT0 OUT0

ZD_IN ZD_IN

if the failed reference is once again available: either stay on Reference B or revert to Reference A. If neither reference can be used, the AD9523 supports a holdover mode. A reference select pin (REF_SEL, Pin 16) is available to manually select which input reference is active (see Table 4 2). The accuracy of the holdover is dependent on the external VCXO frequency stability at half supply voltage.

Any of the divider settings are programmable via the serial programming port, enabling a wide range of input/output frequency ratios under program control. The dividers also include a programmable delay to adjust timing of the output signals, if required.

The output is compatible with LVPECL, LVDS, or HSTL logic levels (see the Input/Output Termination Recommendations section); however, the AD9523 is implemented only in CMOS.

The loop filters of each PLL are integrated and programmable. Only a single external capacitor for each of the two PLL loop filters is required.

The AD9523 operates over the extended industrial temperature range of −40°C to +85°C.

08439-020

AD9523

COMPONENT BLOCKS—INPUT PLL (PLL1)

PLL1 General Description

Fundamentally, the input PLL (referred to as PLL1) consists of a phase-frequency detector (PFD), charge pump, passive loop filter, and an external VCXO operating in a closed loop.

PLL1 has the flexibility to operate with a loop bandwidth of approximately 10 Hz to 100 Hz. This relatively narrow loop bandwidth gives the AD9523 the ability to suppress jitter that appears on the input references (REFA and REFB). The output of PLL1 then becomes a low jitter phase-locked version of the reference input system clock.

PLL1 Reference Clock Inputs

The AD9523 features two separate differential reference clock inputs, REFA and REFB. These inputs can be configured to operate in full differential mode or single-ended CMOS mode.

In differential mode, these pins are internally self-biased. If

REFA

REFA or REFB is driven single-ended, the unused side ( REFB

) should be decoupled via a suitable capacitor to a quiet

ground. shows the equivalent circuit of REFA or REFB.

Figure 21 It is possible to dc-couple to these inputs, but the dc operation point should be set as specified in the tables.

Specifications

To operate either the REFA or the REFB inputs in 3.3 V CMOS mode, the user must set Bit 5 or Bit 6, respectively, in Register 0x01A (see Tabl e 4 0 ). The single-ended inputs can be driven by either a dc-coupled CMOS level signal or an ac-coupled sine wave or square wave.

The differential reference input receiver is powered down when the differential reference input is not selected, or when the PLL is powered down. The single-ended buffers power down when the PLL is powered down, when their respective individual powerdown registers are set, or when the differential receiver is selected.

The REFB R divider uses the same value as the REFA R divider unless Bit 7, the enable REFB R divider independent division control bit in Register 0x01C, is programmed as shown in Tab le 4 2 .

PLL1 Loop Filter

The PLL1 loop filter requires the connection of an external capacitor from LF1_EXT_CAP (Pin 7) to ground. The value of the external capacitor depends on the use of an external VCXO, as well as such configuration parameters as input clock rate and desired bandwidth. Normally, a 0.3 µF capacitor allows the loop bandwidth to range from 10 Hz to 100 Hz and ensures loop stability over the intended operating parameters of the device (see Tabl e 43 for R

AD9523

ZERO

CHARGE

PUMP

values).

ZERO

LF1_EXT_CAP LDO_PLL1

POLE1

POLE2

Figure 23. PLL1 Loop Filter

BUFFER

OSC_CTRL

1kΩ

0.3µF

Table 19. PLL1 Loop Filter Programmable Values

ZERO

(kΩ)

POLE1

(nF)

POLE2

(kΩ)

POLE2

(nF)

LF1_EXT_CAP1 (μF)

883 1.5 fixed 165 fixed 0.337 fixed 0.3 677 341 135 10 External

External loop filter capacitor.

An external R-C low-pass filter should be used at the OSC_CTRL output. The values shown in Figure 23 add an additional low-pass pole at ~530 Hz. This R-C network filters the noise associated with the OSC_CTRL buffer to achieve the best noise performance at the 1 kHz offset region.

08439-022

LF1_EXT_CAP

REFA REFA

REF_SEL

REFB REFB

REF_TEST

DIVIDE- BY1, 2, .. .1023

SWITCH-

OVER

DIVIDE- BY1, 2, .. .1023

3.3V CMOS OR 1.8V

DIFFERENTIAL

DIVIDE-BY-

1, 2, ...63

1.8V LDO

VDD3_PLL LDO_PLL1

CONTROL

Figure 24. Input PLL (PLL1) Block Diagram

Rev. B | Page 21 of 56

0.5µA LSB

ZERO

CHARGE

PUMP

7 BITS,

POLE1

DIVIDE- BY-

1, 2, .. .1023

POLE2

AD9523

OSC_CTRL

VCXO

OSC_IN

08439-021

AD9523

PLL1 Input Dividers

Each reference input feeds a dedicated reference divider block. The input dividers provide division of the reference frequency in integer steps from 1 to 1023. They provide the bulk of the frequency prescaling that is necessary to reduce the reference frequency to accommodate the bandwidth that is typically desired for PLL1.

PLL1 Reference Switchover

The reference monitor verifies the presence/absence of the prescaled REFA and REFB signals (that is, after division by the input dividers). The status of the reference monitor guides the activity of the switchover control logic. The AD9523 supports automatic and manual PLL reference clock switching between REFA (the REFA and REFB

pins). This feature supports networking and infrastructure

REFA

pins) and REFB (the REFB and

applications that require redundant references.

There are several configurable modes of reference switchover. The manual switchover is achieved either via a program-ming register setting or by using the REF_SEL pin. The automatic switchover occurs when REFA disappears and there is a reference on REFB.

The reference automatic switchover can be set to work as follows:

• Nonrevertive: stay on REFB. Switch from REFA to REFB

when REFA disappears, but do not switch back to REFA if it reappears. If REFB disappears, then go back to REFA.

• Revert to REFA. Switch from REFA to REFB when REFA

disappears. Return to REFA from REFB when REFA returns.

See Tab le 4 2 for the PLL1 miscellaneous control register bit settings.

PLL1 Holdover

In the absence of both input references, the device enters holdover mode. Holdover is a secondary function that is provided by PLL1. Because PLL1 has an external VCXO available as a frequency source, it continues to operate in the

absence of the input reference signals. When the device switches to holdover, the charge pump tristates. The device continues operating in this mode until a reference signal becomes available. Then the device exits holdover mode, and PLL1 resynchronizes with the active reference. In addition to tristate, the charge pump can be forced to VCC/2 during holdover (see Ta b l e 42, Bit 6 in Register 0x01C).

COMPONENT BLOCKS—OUTPUT PLL (PLL2)

PLL2 General Description

The output PLL (referred to as PLL2) consists of an optional input reference doubler, phase-frequency detector (PFD), a partially integrated analog loop filter (see Figure 25), an integrated voltage-controlled oscillator (VCO), and a feedback divider. The VCO produces a nominal 3.8 GHz signal with an output divider that is capable of division ratios of 4 to 11.

The PFD of the output PLL drives a charge pump that increases, decreases, or holds constant the charge stored on the loop filter capacitors (both internal and external). The stored charge results in a voltage that sets the output frequency of the VCO. The feedback loop of the PLL causes the VCO control voltage to vary in a way that phase locks the PFD input signals.

The gain of PLL2 is proportional to the current delivered by the charge pump. The loop filter bandwidth is chosen to reduce noise contributions from PLL sources that could degrade phase noise requirements.

The output PLL has a VCO with multiple bands spanning a range of 3.6 GHz to 4.0 GHz. However, the actual operating frequency within a particular band depends on the control voltage that appears on the loop filter capacitor. The control voltage causes the VCO output frequency to vary linearly within the selected band. This frequency variability allows the control loop of the output PLL to synchronize the VCO output signal with the reference signal applied to the PFD. Typically, the device automatically selects the appropriate band as part of its calibration process (invoked via the VCO control register at Address 0x0F3).

PLL1_OUT

AD9523

DIVIDE BY

1, 2, 4, 8, 16

×2

PFD

LF2_EXT_CAP

ZERO

CHARGE PUMP

8 BITS, 3. 5µA LSB

A/B

COUNTER S

Figure 25. Output PLL (PLL2) Block Diagram

Rev. B | Page 22 of 56

LDO_VCO

POLE1

N DIVIDER

POLE2

DIVIDE-BY-4

PRESCALER

LDO

PLL_1.8V

DIVIDE BY

4, 5, 6, .. .11

LDO_PLL2VDD3_PLL2

TO DIST/ RESYNC

08439-023

AD9523

Input 2× Frequency Multiplier

The 2× frequency multiplier provides the option to double the frequency at the PLL2 input. This allows the user to take advantage of a higher frequency at the input to the PLL (PFD) and, thus, allows for reduced in-band phase noise and greater separation between the frequency generated by the PLL and the modulation spur associated with PFD. However, increased reference spur separation results in harmonic spurs introduced by the frequency multiplier that increase as the duty cycle deviates from 50% at the OSC_IN inputs. As such, beneficial use of the frequency multiplier is application-specific. Typically, a VCXO with proper interfacing has a duty cycle that is approximately 50% at the OSC_IN inputs. Note that the maximum output frequency of the 2× frequency multipliers must not exceed the maximum PFD rate that is specified in Tabl e 11 .

PLL2 Feedback Divider

PLL2 has a feedback divider (N divider) that enables it to provide integer frequency up-conversion.

bination of a prescaler (P) and two counters, A and B.

divider value is

The PLL2 N divider is a com-

The total

N = (P × B) + A

where P = 4.

The feedback divider is a dual modulus prescaler architecture, with a nonprogrammable P that is equal to 4. The value of the B counter can be from 4 to 63, and the value of the A counter can be from 0 to 3. However, due to the architecture of the divider, there are constraints, as listed in

Tabl e 45 .

PLL2 Loop Filter

The PLL2 loop filter requires the connection of an external capacitor from LF2_EXT_CAP (Pin 11) to LDO_VCO (Pin 14), as illustrated in Figure 25. The value of the external capacitor depends on the operating mode and the desired phase noise performance. For example, a loop bandwidth of approximately 500 kHz produces the lowest integrated jitter. A lower bandwidth produces lower phase noise at 1 MHz but increases the total integrated jitter.

Table 20. PLL2 Loop Filter Programmable Values

ZERO

(Ω)

3250 48 900 Fixed at 16 Typical at 1000 3000 40 450 2750 32 300 2500 24 225 2250 16 2100 8 2000 0 1850

External loop filter capacitor.

POLE1

(pF)

POLE2

(Ω)

POLE2

(pF)

LF2_EXT_CAP1 (pF)

VCO Divider

The VCO divider provides frequency division between the internal VCO and the clock distribution. The VCO divider can be set to divide by 4, 5, 6, 7, 8, 9, 10, or 11.

VCO Calibration

The AD9523 on-chip VCO must be manually calibrated to ensure proper operation over process and temperature. This is accomplished by setting the calibrate VCO bit (Register 0x0F3, Bit 1) to 1. (This bit is not self-clearing.) The setting can be performed as part of the initial setup before executing the IO_Update bit (Register 0x234, Bit 0 = 1). A readback bit, VCO calibration in progress (Register 0x22D, Bit 0), indicates when a VCO calibration is in progress by returning a logic true (that is, Bit 0 = 1). If the EEPROM is in use, setting the calibrate VCO bit to 1 before saving the register settings to the EEPROM ensures that the VCO calibrates automatically after the EEPROM has loaded. After calibration, it is recommended that a sync be initiated (see the Clock Distribution Synchronization section).

Note that the calibrate VCO bit defaults to 0. This bit must change from 0 to 1 to initiate a calibration sequence. Therefore, any subsequent calibrations require the following sequence:

1. Register 0x0F3, Bit 1 (calibrate VCO bit) = 0

2. Register 0x234, Bit 0 (IO_Update bit) = 1

3. Register 0x0F3, Bit 1 (calibrate VCO bit) = 1

4. Register 0x234, Bit 0 (IO_Update bit) = 1

VCO calibration is controlled by a calibration controller that runs off the VCXO input clock. The calibration requires that PLL2 be set up properly to lock the PLL2 loop and that the VCXO clock be present.

During power-up or reset, the distribution section is automatically held in sync until the first VCO calibration is finished. Therefore, no outputs can occur until VCO calibration is complete and PLL2 is locked.

Initiate a VCO calibration under the following conditions:

• After changing any of the PLL2 B counter and A counter

settings or after a change in the PLL2 reference clock frequency. This means that a VCO calibration should be initiated any time that a PLL2 register or reference clock changes such that a different VCO frequency is the result.

• Whenever system calibration is desired. The VCO is designed

to operate properly over extremes of temperature even when it is first calibrated at the opposite extreme. However, a VCO calibration can be initiated at any time, if desired.

Rev. B | Page 23 of 56

AD9523

CLOCK DISTRIBUTION

The clock distribution block provides an integrated solution for generating multiple clock outputs based on frequency dividing the PLL2 VCO divider output. The distribution output consists of 14 channels (OUT0 to OUT13). Each of the output channels has a dedicated divider and output driver, as shown in Figure 25. The AD9523 also has the capability to route the VCXO output to four of the outputs (OUT0 to OUT3).

Clock Dividers

The output clock distribution dividers are referred to as D0 to D13, corresponding to output channels OUT0 through OUT13, respectively. Each divider is programmable with 10 bits of division depth that is equal to 1 to 1024. Dividers have duty cycle correction to always give 50% duty cycle, even for odd divides.

Output Power-Down

Each of the output channels offers independent control of the power-down functionality via the Channel 0 to Channel 13 control registers (see Ta b le 5 0). Each output channel has a dedicated power-down bit for powering down the output driver. However, if all 14 outputs are powered down, the entire distribution output enters a deep sleep mode. Although each channel has a channel power-down control signal, it may sometimes be desirable to power down an output driver while maintaining the divider’s synchronization with the other channel dividers. This is accomplished by placing the output in tristate mode (this works in CMOS mode, as well).

Multimode Output Drivers

The user has independent control of the operating mode of each of the fourteen output channels via the Channel 0 to Channel 13 control registers (see Tabl e 50 ). The operating mode control includes the following:

• Logic family and pin functionality

• Output drive strength

• Output polarity

If the output channel is ac-coupled to the circuit to be clocked, changing the mode varies the voltage swing to determine sensitivity to the drive level. For example, in LVDS mode, a current of

3.5 mA causes a 350 mV peak voltage. Likewise, in LVPECL mode, a current of 8 mA causes an 800 mV peak voltage at the 100 Ω load resistor.

In addition to the four mode bits, each of the 14 Channel 0 to Channel 13 control registers includes the following control bits:

• Invert divider output. Enables the user to choose between

normal polarity and inverted polarity. Normal polarity is the default state. Inverted polarity reverses the representation of Logic 0 and Logic 1, regardless of the logic family.

• Ignore sync. Makes the divider ignore the

SYNC

signal

from any source.

• Power down channel. Powers down the entire channel.

• Lower power mode.

• Driver mode.

• Channel divider.

• Divider phase.

DD3_OUT[x:y]

1.25V LVDS

VDD – 1.3V LVPECL

COMMON-MODE

CIRCUIT

+–

100Ω LOAD

50Ω

HSTL ENABLED

The four least significant bits (LSBs) of each of the 14 Channel 0 to Channel 13 control registers comprise the driver mode bits. The mode value selects the desired logic family and pin functionality

3.5mA/8mA

LVDS/LVPECL

ENABLED

50Ω

HSTL ENABLED

of an output channel, as listed in Tab le 5 0. This driver design allows a common 100 Ω external resistor for all the different driver modes of operation that are illustrated in Figure 26.

Rev. B | Page 24 of 56

Figure 26. Multimode Driver

08439-031

AD9523

Clock Distribution Synchronization

A block diagram of the clock distribution synchronization functionality is shown in Figure 27. The synchronization sequence begins with the primary synchronization signal, which ultimately results in delivery of a synchronization strobe to the clock distribution logic.

As indicated, the primary synchronization signal originates from one of the following sources:

• Direct synchronization source via the sync dividers bit (see

• Device pin,

SYNC

(Pin 17)

An automatic synchronization of the divider is initiated the first time that PLL2 locks after a power-up or reset event. Subsequent lock/unlock events do not initiate a resynchronization of the distribution dividers unless they are preceded by a power-down or reset of the part.

Both sources of the primary synchronization signal are logic OR’d; therefore, any one of them can synchronize the clock distribution output at any time. When using the sync dividers bit, the user

first sets and then clears the bit. The synchronization event is the clearing operation (that is, the Logic 1 to Logic 0 transition of the bit). The dividers are all automatically synchronized to each other when PLL2 is ready. The dividers support programmable phase offsets from 0 to 63 steps, in half periods of the input clock (for example, the VCO divider output clock). The phase offsets are incorporated in the dividers through a preset for the first output clock period of each divider. Phase offsets are supported only by programming the initial phase and divide value and then issuing a sync to the distribution (automatically at startup or manually, if desired).

In normal operation, the phase offsets are already programmed through the EEPROM or the SPI/I

C port before the AD9523 starts to provide outputs. Although the user cannot adjust the phase offsets while the dividers are operating, it is possible to adjust the phase of all the outputs together without powering down PLL1 and PLL2. This is accomplished by programming the new phase offset, using Bits[7:2] in Register 0x192 (see Tabl e 50 ) and then issuing a divide sync signal by using the SYNC

pin or the sync dividers bit (Register 0x232, Bit 0).

DIVIDE

PHASE

SYNC

DIVIDER

OUT

DRIVER

OUTx

VCO OUTPUT DIVIDER

FAN OUT

SYNC (PIN 17)

SYNC DIVIDERS BI T

Figure 27. Clock Output Synchronization Block Diagram

SYNC

08439-025

SYNC

VCO DIVIDER OUT PUT CLOCK

DIVIDE = 2, PHASE = 0

DIVIDE = 2, PHASE = 6

CONTROL

6 × 0.5 PERIODS

Figure 28. Clock Output Synchronization Timing Diagram

8439-026

Rev. B | Page 25 of 56

AD9523

All outputs that are not programmed to ignore the sync are disabled temporarily while the sync is active. Note that, if an output is used for the zero delay path, it also disappears momentarily. However, this is desirable because it ensures that all the synchronized outputs have a deterministic phase relation-ship with respect to the zero delay output and, therefore, also with respect to the input.

ZERO DELAY OPERATION

Zero delay operation aligns the phase of the output clocks with the phase of the external PLL reference input. The OUT0 output is designed to be used as the output for zero delay. There are two zero delay modes on the AD9523: internal and external (see Figure 29). Note that the external delay mode provides better matching than the internal delay mode because the output drivers are included in the zero delay path. Setting the anitbacklash pulse width control of PLL1 to maximum gives the best zero delay matching.

Internal Zero Delay Mode

The internal zero delay function of the AD9523 is achieved by feeding the output of Channel Divider 0 back to the PLL1 N divider. Bit 5 in Register 0x01B is used to select internal zero delay mode (see Tabl e 4 1 ). In the internal zero delay mode, the output of Channel Divider 0 is routed back to the PLL1 (N divider)

through a mux. PLL1 synchronizes the phase/edge of the output of Channel Divider 0 with the phase/edge of the reference input.

Because the channel dividers are synchronized to each other, the outputs of the channel divider are synchronous with the reference input.

External Zero Delay Mode

The external zero delay function of the AD9523 is achieved by feeding OUT0 back to the ZD_IN input and, ultimately, back to the PLL1 N divider. In Figure 29, the change in signal routing for external zero delay is external to the AD9523.

Bit 5 in Register 0x01B is used to select the external zero delay mode. In external zero delay mode, OUT0 must be routed back to PLL1 (the N divider) through the ZD_IN and

ZD_IN

pins.

PLL1 synchronizes the phase/edge of the feedback output clock with the phase/edge of the reference input. Because the channel dividers are synchronized to each other, the clock outputs are synchronous with the reference input. Both the reference path delay and the feedback delay from ZD_IN are designed to have the same propagation delay from the output drivers and PLL components to minimize the phase offset between the clock output and the reference input to achieve zero delay.

REFA REFA

ZD_IN

FEEDBACK

DELAY

REF

DELAY

INTERNAL FB

PFD

OUT0OUT0ZD_IN

ENB

AD9523

Figure 29. Zero Delay Function

08439-027

Rev. B | Page 26 of 56

AD9523

SERIAL CONTROL PORT

The AD9523 serial control port is a flexible, synchronous serial communications port that allows an easy interface with many industry-standard microcontrollers and microprocessors. The AD9523 serial control port is compatible with most synchronous transfer formats, including Philips IC®, Motorola® SPI, and Intel® SSR protocols. The AD9523 IC implementation deviates from the classic IC specification in two specifications, and these deviations are documented in Tabl e 1 5 of this data sheet. The serial control port allows read/write access to all registers that configure the AD9523.

SPI/I²C PORT SELECTION

The AD9523 has two serial interfaces, SPI and IC. Users can select either the SPI or IC depending on the states (logic high, logic low) of the two logic level input pins, SP1 and SP0, when power is applied or after a 40 kΩ pull-down resistor).

the SPI interface is active. Otherwise, I

different I in . The five MSBs of the slave address are hardware

Tabl e 21

C slave address settings (seven bits wide), as shown

RESET

(each pin has an internal

When both SP1 and SP0 are low,

C is active with three

coded as 11000, and the two LSBs are determined by the logic levels of the SP1 and SP0 pins.

Table 21. Serial Port Mode Selection

SP1 SP0 Address

Low Low SPI Low High I2C: 1100000 High Low I2C: 1100001 High High I2C: 1100010

I²C SERIAL PORT OPERATION

The AD9523 IC port is based on the IC fast mode standard. The AD9523 supports both IC protocols: standard mode (100 kHz) and fast mode (400 kHz).

The AD9523 IC port has a 2-wire interface consisting of a serial data line (SDA) and a serial clock line (SCL). In an IC bus system, the AD9523 is connected to the serial bus (data bus SDA and clock bus SCL) as a slave device, meaning that no clock is generated by the AD9523. The AD9523 uses direct 16-bit (two bytes) memory addressing instead of traditional 8-bit (one byte) memory addressing.

I2C Bus Characteristics

Table 22. I2C Bus Definitions

Abbreviation Definition

S Start Sr Repeated start P A A W

Stop Acknowledge No acknowledge Write

R Read

One pulse on the SCL clock line is generated for each data bit that is transferred.

The data on the SDA line must not change during the high period of the clock. The state of the data line can change only when the clock on the SCL line is low.

SDA

SCL

DATA LINE

STABLE;

DATA VALID

Figure 30. Valid Bit Transfer

CHANGE OF DATA

ALLOWED

A start condition is a transition from high to low on the SDA line while SCL is high. The start condition is always generated by the master to initialize the data transfer.

A stop condition is a transition from low to high on the SDA line while SCL is high. The stop condition is always generated by the master to end the data transfer.

SCL

START

CONDITION

Figure 31. Start and Stop Conditions

STOP

CONDITIO N

A byte on the SDA line is always eight bits long. An acknowledge bit must follow every byte. Bytes are sent MSB first.

The acknowledge bit is the ninth bit attached to any 8-bit data byte. An acknowledge bit is always generated by the receiving device (receiver) to inform the transmitter that the byte has been received. It is accomplished by pulling the SDA line low during the ninth clock pulse after each 8-bit data byte.

8439-160

08439-161

Rev. B | Page 27 of 56

AD9523

SDA

MSB

ACKNOWLEDGE FROM

SLAVE-RECEIV ER

ACKNOWLEDGE FROM

SLAVE-RECEIVER

SCL

1 2 8 9 1 2 83 TO 73 TO 7 9 10

Figure 32. Acknowledge Bit

MSB = 0

ACKNOWLEDGE FROM

SLAVE-RECEIV ER

1 2 8 9 1 2 83 TO 73 TO 7 9 10

Figure 33. Data Transfer Process (Master Write Mode, 2-Byte Transfer Used for Illustration)

MSB = 1

ACKNOWLEDGE FROM

MASTER-RECEIVER

1 2 8 9 1 2 83 TO 73 TO 7 9 10

Figure 34. Data Transfer Process (Master Read Mode, 2-Byte Transfer Used for Illustration)

The no acknowledge bit is the ninth bit attached to any 8-bit data byte. A no acknowledge bit is always generated by the receiving device (receiver) to inform the transmitter that the byte has not been received. It is accomplished by leaving the SDA line high during the ninth clock pulse after each 8-bit data byte.

Data Transfer Process

The master initiates data transfer by asserting a start condition. This indicates that a data stream follows. All IC slave devices connected to the serial bus respond to the start condition.

The master then sends an 8-bit address byte over the SDA line,

consisting of a 7-bit slave address (MSB first), plus an R/

bit.

This bit determines the direction of the data transfer, that is, whether data is written to or read from the slave device (0 = write, 1 = read).

The peripheral whose address corresponds to the transmitted address responds by sending an acknowledge bit. All other devices on the bus remain idle while the selected device waits for data to be read from or written to it. If the R/ (transmitter) writes to the slave device (receiver). If the R/

bit is 0, the master

bit is 1,

the master (receiver) reads from the slave device (transmitter).

The format for these commands is described in the Data Transfe r Format section.

Data is then sent over the serial bus in the format of nine clock pulses, one data byte (eight bits) from either master (write mode) or slave (read mode), followed by an acknowledge bit from the receiving device. The number of bytes that can be transmitted per transfer is unrestricted. In write mode, the first two data bytes immediately after the slave address byte are the internal memory (control registers) address bytes with the high address byte first.

Rev. B | Page 28 of 56

08439-162

ACKNOWLEDGE FROM

SLAVE-RECEI VER

08439-163

NO ACKNOWLEDGE

FROM

SLAVE-RECEIV ER

08439-164

This addressing scheme gives a memory address of up to 2

− 1 = 65,535. The data bytes after these two memory address bytes are register data written into the control registers. In read mode, the data bytes after the slave address byte are register data read from the control registers. A single I

C transfer can contain multiple data bytes that can be read from or written to control registers whose address is automatically incremented starting from the base memory address.

When all data bytes are read or written, stop conditions are established. In write mode, the master (transmitter) asserts a stop condition to end data transfer during the 10th clock pulse following the acknowledge bit for the last data byte from the slave device (receiver). In read mode, the master device (receiver) receives the last data byte from the slave device (transmitter) but does not pull it low during the ninth clock pulse. This is known as a no acknowledge bit. Upon receiving the no acknowledge bit, the slave device knows that the data transfer is finished and releases the SDA line. The master then takes the data line low during the low period before the 10th clock pulse and high during the 10th clock pulse to assert a stop condition.

A repeated start (Sr) condition can be used in place of a stop condition. Furthermore, a start or stop condition can occur at any time, and partially transferred bytes are discarded.

For an I

C data write transfer containing multiple data bytes, the peripheral drives a no acknowledge for the data byte that follows a write to Register 0x234, thereby ending the I

For an I

C data read transfer containing multiple data bytes,

C transfer.

the peripheral drives data bytes of 0x00 for subsequent reads that follow a read from Register 0x234.

AD9523

Data Transfer Format

Send byte format. The send byte protocol is used to set up the register address for subsequent commands.

S Slave Address W A RAM Address High Byte A RAM Address Low Byte A P

Write byte format. The write byte protocol is used to write a register address to the RAM, starting from the specified RAM address.

RAM Address

S Slave Address W A

High Byte

Receive byte format. The receive byte protocol is used to read the data byte(s) from the RAM, starting from the current address.

S Slave Address R A RAM Data 0 A RAM Data 1 A RAM Data 2

Read byte format. The combined format of the send byte and the receive byte.

Slave

Address

W A

RAM Address

High Byte

I²C Serial Port Timing

SDA

SET; DAT

RISE

SCL

FALL

LOW

RAM Address

Low Byte

RAM Address

Low Byte

FALL

A Sr

Slave

Address

RAM

Data 0

HLD; STR

R A

RAM

Data 0

SPIKE

RAM

Data 1

RISE

RAM

Data 1

IDLE

RAM

Data 2

RAM

Data 2

A P

HLD; STR

S Sr P S

HLD; DAT

HIGH

SET; STR

Figure 35. I²C Serial Port Timing

Table 23. IC Timing Definitions

Parameter Description

I²C clock frequency

I2C

Bus idle time between stop and start conditions

IDLE

Hold time for repeated start condition

HLD; STR

Setup time for repeated start condition

SET; STR

Setup time for stop condition

SET; STP

Hold time for data

HLD; DAT

Setup time for data

SET; DAT

Duration of SCL clock low

LOW

Duration of SCL clock high

HIGH

SCL/SDA rise time

RISE

SCL/SDA fall time

FAL L

Voltage spike pulse width that must be suppressed by the input filter

SPIKE

SET; STP

08439-165

Rev. B | Page 29 of 56

AD9523

SPI SERIAL PORT OPERATION

Pin Descriptions

SCLK (serial clock) is the serial shift clock. This pin is an input. SCLK is used to synchronize serial control port reads and writes. Write data bits are registered on the rising edge of this clock, and read data bits are registered on the falling edge. This pin is internally pulled down by a 40 kΩ resistor to ground.

SDIO (serial data input/output) is a dual-purpose pin and acts either as an input only (unidirectional mode) or as an input/ output (bidirectional mode). The AD9523 defaults to the bidirectional I/O mode.

SDO (serial data out) is used only in the unidirectional I/O mode as a separate output pin for reading back data. SDO is always active; therefore, the unidirectional I/O mode should not be used in a multislave environment.

(chip select bar) is an active low control that gates the read and write cycles. When state. This pin is internally pulled up by a 40 kΩ resistor to

VDD3_REF.

SPI Mode Operation

In SPI mode, single or multiple byte transfers are supported, as well as MSB first or LSB first transfer formats. The AD9523 serial control port can be configured for a single bidirectional I/O pin (SDIO only) or for two unidirectional I/O pins (SDIO/ SDO). By default, the AD9523 is in bidirectional mode. Short instruction mode (8-bit instructions) is not supported. Only long (16-bit) instruction mode is supported.

A write or a read operation to the AD9523 is initiated by pulling CS

low.

The

stalled high mode is supported in data transfers where three or fewer bytes of data (plus instruction data) are transferred (see ). In this mode, the Tabl e 24 high on any byte boundary, allowing time for the system controller to process the next byte. however, it can go high during either phase (instruction or data) of the transfer.

During this period, the serial control port state machine enters a wait state until all data is sent. If the system controller decides to abort the transfer before all of the data is sent, the state machine must be reset either by completing the remaining transfers or by returning

low for at least one complete SCLK cycle (but fewer than eight SCLK cycles). Raising the boundary terminates the serial transfer and flushes the buffer.

is high, SDIO is in a high impedance

SCLK/SCL

SDIO/SDA

SDO

Figure 36. Serial Control Port

AD9523

SERIAL

CONTROL

PORT

8439-034

pin can temporarily return

can go high only on byte boundaries;

pin on a nonbyte

Rev. B | Page 30 of 56

In streaming mode (see Ta b le 2 4), any number of data bytes can be transferred in a continuous stream. The register address is automatically incremented or decremented (see the SPI MSB/LSB First Transfers section).

must be raised at the end of the last

byte to be transferred, thereby ending streaming mode.

Communication Cycle—Instruction Plus Data

There are two parts to a communication cycle with the AD9523. The first part writes a 16-bit instruction word into the AD9523, coincident with the first 16 SCLK rising edges. The instruction word provides the AD9523 serial control port with information regarding the data transfer, which is the second part of the communication cycle. The instruction word defines whether the upcoming data transfer is a read or a write, the number of bytes in the data transfer, and the starting register address for the first byte of the data transfer.

Write

If the instruction word is for a write operation, the second part is the transfer of data into the serial control port buffer of the AD9523. Data bits are registered on the rising edge of SCLK.

The length of the transfer (one, two, or three bytes or streaming mode) is indicated by two bits (W1, W0) in the instruction byte. When the transfer is one, two, or three bytes but not streaming,

can be raised after each sequence of eight bits to stall the bus (except after the last byte, where it ends the cycle). When the bus is stalled, the serial transfer resumes when

the

pin on a nonbyte boundary resets the serial control port.

is lowered. Raising

During a write, streaming mode does not skip over reserved or blank registers, and the user can write 0x00 to the reserved register addresses.

Because data is written into a serial control port buffer area, and not directly into the actual control registers of the AD9523, an additional operation is needed to transfer the serial control port buffer contents to the actual control registers of the AD9523, thereby causing them to become active. The update registers operation consists of setting the self-clearing IO_Update bit, Bit 0 of Register 0x234 (see Table 56 ). Any number of data bytes can be changed before executing an update registers operation. The update registers simultaneously actuates all register changes that have been written to the buffer since any previous update.

Read

The AD9523 supports only the long instruction mode. If the instruction word is for a read operation, the next N × 8 SCLK cycles clock out the data from the address specified in the instruction word, where N is 1 to 3 as determined by Bits[W1:W0]. If N = 4, the read operation is in streaming mode, continuing

until

is raised. Streaming mode does not skip over reserved or blank registers. The readback data is valid on the falling edge of SCLK.

AD9523

The default mode of the AD9523 serial control port is the bidirectional mode. In bidirectional mode, both the sent data and the readback data appear on the SDIO pin. It is also possible to set the AD9523 to unidirectional mode. In unidirectional mode, the readback data appears on the SDO pin.

A readback request reads the data that is in the serial control port buffer area or the data that is in the active registers (see Figure 37).

SCLK/SCL

SDIO/SDA

SDO

Figure 37. Relationship Between Serial Control Port Buffer Registers and

SERIAL

CONTROL

PORT

BUFFER

REGISTERS

UPDATE

REGISTERS

Active Registers

ACTIVE

REGISTERS

8439-035

SPI INSTRUCTION WORD (16 BITS)

The MSB of the instruction word is R/W, which indicates whether the instruction is a read or a write. The next two bits ([W1:W0]) indicate the length of the transfer in bytes. The final 13 bits are the address ([A12:A0]) at which to begin the read or write operation.

For a write, the instruction word is followed by the number of bytes of data indicated by Bits[W1:W0] (see Tab l e 2 4 ).

Table 24. Byte Transfer Count

0 0 1 0 1 2 1 0 3 1 1 Streaming mode

Bits[A12:A0] select the address within the register map that is written to or read from during the data transfer portion of the communications cycle. Only Bits[A11:A0] are needed to cover the range of the 0x234 registers used by the AD9523. Bit A12 must always be 0. For multibyte transfers, this address is the starting byte address. In MSB first mode, subsequent bytes decrement the address.

W0 Bytes to Transfer

SPI MSB/LSB FIRST TRANSFERS

The AD9523 instruction word and byte data can be MSB first or LSB first. Any data written to Register 0x000 must be mirrored: Bit 7 is mirrored to Bit 0, Bit 6 to Bit 1, Bit 5 to Bit 2, and Bit 4 to Bit 3. This makes it irrelevant whether LSB first or MSB first is in effect. The default for the AD9523 is MSB first.

When LSB first is set by Register 0x000, Bit 1 and Register 0x000, Bit 6, it takes effect immediately because it affects only the operation of the serial control port and does not require that an update be executed.

When MSB first mode is active, the instruction and data bytes must be written from MSB to LSB. Multibyte data transfers in MSB first format start with an instruction byte that includes the register address of the most significant data byte. Subsequent data bytes must follow in order from the high address to the low address. In MSB first mode, the serial control port internal address generator decrements for each data byte of the multibyte transfer cycle.

When LSB first mode is active, the instruction and data bytes must be written from LSB to MSB. Multibyte data transfers in LSB first format start with an instruction byte that includes the register address of the least significant data byte, followed by multiple data bytes. In a multibyte transfer cycle, the internal byte address generator of the serial port increments for each byte.

The AD9523 serial control port register address decrements from the register address just written toward 0x000 for multibyte I/O operations if the MSB first mode is active (default). If the LSB first mode is active, the register address of the serial control port increments from the address just written toward 0x234 for multibyte I/O operations. Unused addresses are not skipped for these operations.

For multibyte accesses that cross Address 0x234 or Address 0x000 in MSB first mode, the SPI internally disables writes to subsequent registers and returns zeros for reads to subsequent registers.

Streaming mode always terminates when crossing address boundaries (as shown in

Table 25. Streaming Mode (No Addresses Are Skipped)

Write Mode Address Direction Stop Sequence

MSB First Decrement …, 0x001, 0x000, stop

Tabl e 25 ).

Table 26. Serial Control Port, 16-Bit Instruction Word, MSB First

MSB LSB I15 I14 I13 I12 I11 I10 I9 I8 I7 I6 I5 I4 I3 I2 I1 I0

R/W

W1 W0 A12 = 0 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0

Rev. B | Page 31 of 56

AD9523

DON'T CARE

SCLK

DON'T CARE

SDIO A12W0W1R/W A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0

16-BIT INST RUCTION HEADE R REGISTER (N) DATA REG ISTER (N – 1) DATA

Figure 38. Serial Control Port Write—MSB First, 16-Bit Instruction, Two Bytes of Data

SCLK

DON'T CARE

SDIO

SDO

DON'T CARE

A12W0W1R/W A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A 1 A0

D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0

REGISTE R (N) DATA16-BIT INST RUCTION HE ADER REGISTE R (N – 1) DATA REG ISTER (N – 2) DATA REG ISTER (N – 3) DATA

Figure 39. Serial Control Port Read—MSB First, 16-Bit Instruction, Four Bytes of Data

HIGH

CLK

DON'T CARE

SCLK

SDIO

DON'T CARE

R/W

LOW

W1W0A12A11A10A9A8A7A6A5D4D3D2D1D0

Figure 40. Serial Control Port Write—MSB First, 16-Bit Instruction, Timing Measurements

DON'T CARE

DON'T

CARE

08439-040

8439-038

08439-039

SCLK

SDIO

DON'T CARE

SCLK

SDIO

SDO

DATA BIT N – 1DAT A BIT N

08439-041

Figure 41. Timing Diagram for Serial Control Port Register Read

A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 D1D0R/WW1W0 D2 D3 D4 D5 D6 D7 D0 D1 D2 D3 D4 D5 D6 D7

16-BIT INST RUCTION HEADE R REGISTER (N) DATA REG ISTER (N + 1) DATA

Figure 42. Serial Control Port Write—LSB First, 16-Bit Instruction, Two Bytes of Data

DON'T CARE

8439-042

Rev. B | Page 32 of 56

AD9523

SCLK

CLK

HIGH

LOW

SDIO

BIT N BIT N + 1

Figure 43. Serial Control Port Timing—Write

Table 27. Serial Control Port Timing

Parameter Description

tDS Setup time between data and rising edge of SCLK tDH Hold time between data and rising edge of SCLK t

Period of the clock

CLK

tS tC t

Minimum period that SCLK should be in a logic high state

HIGH

Minimum period that SCLK should be in a logic low state

LOW

SCLK to valid SDIO and SDO (see Figure 41)

Setup time between the CS falling edge and SCLK rising edge (start of communication cycle) Setup time between the SCLK rising edge and CS

rising edge (end of communication cycle)

8439-043

Rev. B | Page 33 of 56

AD9523

EEPROM OPERATIONS

The AD9523 contains an internal EEPROM (nonvolatile memory). The EEPROM can be programmed by the user to create and store a user-defined register setting file when the power is off. This setting file can be used for power-up and chip reset as a default setting. The EEPROM size is 512 bytes. Descriptions of the EEPROM registers that control EEPROM operation can be found in Tabl e 57 and Tabl e 5 8 .

During the data transfer process, the write and read registers are generally not available via the serial port, except for one readback bit: Status_EEPROM (Register 0xB00, Bit 0).

To determine the data transfer state through the serial port in SPI mode, users can read the value of the Status_EEPROM bit (1 = data transfer in process and 0 = data transfer complete).

In IC mode, the user can address the AD9523 slave port with the external IC master (send an address byte to the AD9523). If the AD9523 responds with a no acknowledge bit, the data transfer was not received. If the AD9523 responds with an acknowledge bit, the data transfer process is complete. The user can monitor the Status_EEPROM bit or use Register 0x232, Bit 4 to program the STATUS0 pin to monitor the status of the data transfer (see Tab le 54 ).

To transfer all 512 bytes to the EEPROM, it takes approximately 46 ms. To transfer the contents of the EEPROM to the active register, it takes approximately 40 ms.

RESET

, a hard reset (an asynchronous hard reset is executed by briefly pulling stored in EEPROM (the EEPROM pin = 1) or to the on-chip

setting (the EEPROM pin = 0). A hard reset also executes a SYNC operation, which brings the outputs into phase alignment according to the default settings. When EEPROM is inactive (the EEPROM pin = 0), it takes ~2 µs for the outputs to begin toggling after EEPROM pin = 1), it takes ~40 ms for the outputs to toggle after RESET

RESET

low), restores the chip either to the setting

RESET

is issued. When EEPROM is active (the

is brought high.

WRITING TO THE EEPROM

The EEPROM cannot be programmed directly through the serial port interface. To program the EEPROM and store a register setting file, follow these steps:

1. Program the AD9523 registers to the desired circuit state.

If the user wants PLL2 to lock automatically after power-up, the calibrate VCO bit (Bit 1, Register 0x0F3) must be set to 1. This allows VCO calibration to start automatically after register loading. Note that a valid input reference signal must be present during VCO calibration.

2. Set the IO_Update bit (Bit 0, Register 0x234) to 1.

3. Program the EEPROM buffer registers, if necessary (see

the Programming the EEPROM Buffer Segment section). This step is necessary only if users want to use the EEPROM to control the default settings of some (but not all) of the AD9523 registers, or if they want to control the register setting update sequence during power-up or chip reset.

Rev. B | Page 34 of 56

4. Set the enable EEPROM write bit (Bit 0, Register 0xB02)

to 1 to enable the EEPROM.

5. Set the REG2EEPROM bit (Bit 0, Register 0xB03) to 1.

This starts the process of writing data into the EEPROM to create the EEPROM setting file. This enables the EEPROM controller to transfer the current register values, as well as the memory address and instruction bytes from the EEPROM buffer segment, into the EEPROM. After the write process is completed, the internal controller sets bit REG2EEPROM back to 0. Bit 0 of the Status_EEPROM register (Register 0xB00) is used to indicate the data transfer status between the EEPROM and the control registers (1 = data transfer in process, and 0 = data transfer complete). At the beginning of the data transfer, the Status_EEPROM bit is set to 1 by the EEPROM controller and cleared to 0 at the end of the data transfer. The user can access Status_EEPROM via the STATUS0 pin when the STATUS0 pin is programmed to monitor the Status_EEPROM bit. Alternatively, the user can monitor the Status_EEPROM bit directly.

6. When the data transfer is complete (Status_EEPROM = 0),

set the enable EEPROM write bit (Bit 0 in Register 0xB02) to 1. Clearing the enable EEPROM write bit to 0 disables writing to the EEPROM.

To ensure that the data transfer has completed correctly, verify that the EEPROM data error bit (Bit 0 in Register 0xB01) = 0. A value of 1 in this bit indicates a data transfer error.

READING FROM THE EEPROM

The following reset-related events can start the process of restoring the settings stored in the EEPROM to the control registers. When the EEPROM_SEL pin is set high, do any of the following to initiate an EEPROM read:

• Power up the AD9523.

RESET

• Perform a hardware chip reset by pulling the

RESET

low and then releasing

• Set the self-clearing soft reset bit (Bit 5, Register 0x000) to 1.

When the EEPROM_SEL pin is set low, set the self-clearing Soft_EEPROM bit (Bit 1, Register 0xB02) to 1. The AD9523 then starts to read the EEPROM and loads the values into the AD9523 registers. If the EEPROM_SEL pin is low during reset or power-up, the EEPROM is not active, and the AD9523 default values are loaded instead.

When using the EEPROM to automatically load the AD9523 register values and lock the PLL, the calibrate VCO bit (Bit 1, Register 0x0F3) must be set to 1 when the register values are written to the EEPROM. This allows VCO calibration to start automatically after register loading. A valid input reference signal must be present during VCO calibration.

AD9523

To ensure that the data transfer has completed correctly, verify that the EEPROM data error bit (Bit 0 in Register 0xB01) is set to 0. A value of 1 in this bit indicates a data transfer error.

PROGRAMMING THE EEPROM BUFFER SEGMENT

The EEPROM buffer segment is a register space that allows the user to specify which groups of registers are stored to the EEPROM during EEPROM programming. Normally, this segment does not need to be programmed by the user. Instead, the default power-up values for the EEPROM buffer segment allow the user to store all of the register values from Register 0x000 to Register 0x234 to the EEPROM.

For example, if the user wants to load only the output driver settings from the EEPROM without disturbing the PLL register settings currently stored in the EEPROM, the EEPROM buffer segment can be modified to include only the registers that apply to the output drivers and exclude the registers that apply to the PLL configuration.

There are two parts to the EEPROM buffer segment: register section definition groups and operational codes. Each register section definition group contains the starting address and number of bytes to be written to the EEPROM.

If the AD9523 register map were continuous from Address 0x000 to Address 0x234, only one register section definition group would consist of a starting address of 0x000 and a length of 563 bytes. However, this is not the case. The AD9523 register map is noncontiguous, and the EEPROM is only 512 bytes long. Therefore, the register section definition group tells the EEPROM controller how the AD9523 register map is segmented.

There are three operational codes: IO_Update, end-of-data, and pseudo-end-of-data. It is important that the EEPROM buffer segment always have either an end-of-data or a pseudo-end-ofdata operational code and that an IO_Update operation code appear at least once before the end-of-data operational code.

Register Section Definition Group

The register section definition group is used to define a continuous register section for the EEPROM profile. It consists of three bytes. The first byte defines how many continuous register bytes are in this group. If the user puts 0x000 in the first byte, it means there is only one byte in this group. If the user puts 0x001, it means there are two bytes in this group. The maximum number of registers in one group is 128.

The next two bytes are the low byte and high byte of the memory address (16 bits) of the first register in this group.

IO_Update (Operational Code 0x80)

The EEPROM controller uses this operational code to generate an IO_Update signal to update the active control register bank from the buffer register bank during the download process.

At a minimum, there should be at least one IO_Update operational code after the end of the final register section definition group. This is needed so that at least one IO_Update occurs after all of the AD9523 registers are loaded when the EEPROM is read. If this operational code is absent during a write to the EEPROM, the register values loaded from the EEPROM are not transferred to the active register space, and these values do not take effect after they are loaded from the EEPROM to the AD9523.

End-of-Data (Operational Code 0xFF)

The EEPROM controller uses this operational code to terminate the data transfer process between EEPROM and the control register during the upload and download process. The last item appearing in the EEPROM buffer segment should be either this operational code or the pseudo-end-of-data operational code.

Pseudo-End-of-Data (Operational Code 0xFE)

The AD9523 EEPROM buffer segment has 23 bytes that can contain up to seven register section definition groups. If users want to define more than seven register section definition groups, the pseudo-end-of-data operational code can be used. During the upload process, when the EEPROM controller receives the pseudo-end-of-data operational code, it halts the data transfer process, clears the REG2EEPROM bit (Bit 0, Register 0xB03), and enables the AD9523 serial port. Users can then program the EEPROM buffer segment again and reinitiate the data transfer process by setting the REG2EEPROM bit to 1 and the IO_Update bit (Bit 0, Register 0x234) to 1. The internal IC master then begins writing to the EEPROM, starting from the EEPROM address held from the last writing.

This sequence enables more discrete instructions to be written to the EEPROM than would otherwise be possible due to the limited size of the EEPROM buffer segment. It also permits the user to write to the same register multiple times with a different value each time.

Rev. B | Page 35 of 56

AD9523

Table 28. Example of an EEPROM Buffer Segment

0xA00 0 Number of bytes of the first group of registers (Bits[6:0]) 0xA01 Address of the first group of registers (Bits[15:8]) 0xA02 Address of the first group of registers (Bits[7:0]) 0xA03 0 Number of bytes of the second group of registers (Bits[6:0]) 0xA04 Address of the second group of registers (Bits[15:8]) 0xA05 Address of the second group of registers (Bits[7:0]) 0xA06 0 Number of bytes of the third group of registers (Bits[6:0]) 0xA07 Address of the third group of registers (Bits[15:8]) 0xA08 Address of the third group of registers (Bits[7:0]) 0xA09 IO_Update operational code (0x80) 0xA0A End-of-data operational code (0xFF)

Rev. B | Page 36 of 56

AD9523

POWER DISSIPATION AND THERMAL CONSIDERATIONS

The AD9523 is a multifunctional, high speed device that targets a wide variety of clock applications. The numerous innovative features contained in the device each consume incremental power. If all outputs are enabled in the maximum frequency and mode that have the highest power, the safe thermal operating conditions of the device may be exceeded. Careful analysis and consideration of power dissipation and thermal management are critical elements in the successful application of the AD9523 device.

The AD9523 device is specified to operate within the industrial temperature range of –40°C to +85°C. This specification is conditional, however, such that the absolute maximum junction temperature is not exceeded (as specified in Table 16.). At high operating temperatures, extreme care must be taken when operating the device to avoid exceeding the junction temperature and potentially damaging the device.

Many variables contribute to the operating junction temperature within the device, including

• Selected driver mode of operation

• Output clock speed

• Supply voltage

• Ambient temperature

The combination of these variables determines the junction temperature within the AD9523 device for a given set of operating conditions.

The AD9523 is specified for an ambient temperature (T ensure that T

is not exceeded, an airflow source can be used.

). To

Use the following equation to determine the junction temperature on the application PCB:

= T

+ (ΨJT × PD)

CASE

where:

is the junction temperature (°C).

is the case temperature (°C) measured by the user at the

CASE

top center of the package. Ψ

is the value from Tabl e 17 .

PD is the power dissipation of the AD9523.

Valu es of θ design considerations. θ approximation of T

where T

Valu es of θ

are provided for package comparison and PCB

can be used for a first-order

by the equation

= TA + (θJA × PD)

is the ambient temperature (°C).

are provided for package comparison and PCB

design considerations when an external heat sink is required.

Valu es of Ψ

are provided for package comparison and PCB

design considerations.

CLOCK SPEED AND DRIVER MODE

Clock speed directly and linearly influences the total power dissipation of the device and, therefore, the junction temperature. Two operating frequencies are listed under the incremental power dissipation parameter in Table 3. Using linear interpretation is a sufficient approximation for frequency not listed in the table. When calculating power dissipation for thermal consideration, the amount of power dissipated in the 100 Ω resistor should be removed. If using the data in Tabl e 2, this power is already removed. If using the current vs. frequency graphs provided in the Typical Performance Characteristics section, the power into the load must be subtracted, using the following equation:

SwingVoltageOutputalDifferenti

Ω100

EVALUATION OF OPERATING CONDITIONS

The first step in evaluating the operating conditions is to determine the maximum power consumption (PD) internal to the AD9523. The maximum PD excludes power dissipated in the load resistors of the drivers because such power is external to the device. Use the power dissipation specifications listed in Tabl e 3 to calculate the total power dissipated for the desired configuration. The base typical configuration parameter in Tabl e 3 lists a power of 428 mW, which includes one LVPECL output at 122.88 MHz. If the frequency of operation is not listed in Tabl e 3 , see the Typical Performance Characteristics section, current vs. frequency and driver mode to calculate the power dissipation; then add 20% for maximum current draw. Remove the power dissipated in the load resistor to achieve the most accurate power dissipation internal to the AD9523. See Table 29 for a summary of the incremental power dissipation from the base power configuration for two different examples.

Table 29. Temperature Gradient Examples

Frequency

Description Mode Example 1

Base Typical Configuration

Output Driver 6 × LVPECL Output Driver 6 × LVDS 245.76 110

Total Po wer Example 2

Base Typical Configuration

Output Driver 13 × LVPECL

Total Po wer

428

868

2500

(MHz)

122.88 330

428

983.04 2066

Maximum Power (mW)

Rev. B | Page 37 of 56

AD9523

The second step is to multiply the power dissipated by the thermal impedance to determine the maximum power gradient. For this example, a thermal impedance of

θJA = 20.1°C/W was used.

Example 1

(868 mW × 20.1°C/W) = 17.4°C

With an ambient temperature of 85°C, the junction temperature is

= 85°C + 17.4°C = 102°C

This junction temperature is below the maximum allowable.

Example 2

(2500 mW × 20.1°C/W) = 50.2°C

With an ambient temperature of 85°C, the junction temperature is

= 85°C + 50°C = 135°C

This junction temperature is above the maximum allowable. To operate in the condition of Example 2, the ambient temperature must be lowered to 65°C.

THERMALLY ENHANCED PACKAGE MOUNTING GUIDELINES

Refer to the AN-772 Application Note, A Design and Manufacturing Guide for the Lead Frame Chip Scale Package (LFCSP), for more information about mounting devices with

an exposed paddle.

Rev. B | Page 38 of 56

AD9523

CONTROL REGISTERS

CONTROL REGISTER MAP

Register addresses that are not listed in Tab l e 3 0 are not used, and writing to those registers has no effect. Registers that are marked as reserved should never have their values changed. When writing to registers with bits that are marked reserved, the user should take care to always write the default value for the reserved bits.

Table 30. Control Register Map

Addr (Hex)

Serial Port Configuration

0x004 Readback

0x005 EEPROM customer version ID[7:0] (LSB) 0x00 0x006

Input PLL (PLL1)

0x010 10-bit REFA R divider[7:0] (LSB) 0x00 0x011

0x012 10-bit REFB R divider[7:0] (LSB) 0x00 0x013

0x014 PLL1 reference

0x015 PLL1 reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved 0x00 0x016 10-bit PLL1 feedback divider[7:0] (LSB) 0x00 0x017

0x018 PLL1

0x019

0x01A PLL1

0x01B REF_TEST,

0x01C PLL1

SPI mode serial port configuration

C mode

I serial port configuration

control EEPROM

customer version ID

PLL1 REFA R divider control

PLL1 REFB R divider control

test divider

PLL1 feedback N divider control

PLL1 charge pump control

input receiver control

REFA, REFB, and ZD_IN control

miscellaneous control

(MSB) Bit 7

SDO active

Reserved Reserved Soft reset Reserved Reserved Soft reset Reserved Reserved 0x00

Reserved Reserved Reserved Reserved Reserved Reserved Reserved Read back

Reserved Reserved REF_TEST divider 0x00

charge pump tristate

Reserved Reserved Reserved Enable SPI

REF_TEST input receiver enable

Bypass REF_TEST divider

Enable REFB R divider indepen. division control

Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1

LSB first/ address increment

REFB differential receiver enable

Bypass feedback divider

OSC_CTRL control voltage to VCC/2 when ref clock fai

Soft reset Reserved Reserved Soft reset LSB first/

EEPROM customer version ID[15:8] (MSB) 0x00

Reserved 10-bit REFA R divider[9:8]

Reserved 10-bit REFB R divider[9:8]

Rese rved 10-bit PLL1 feedback divider[9:8]

PLL1 charge pump control 0x0C

control of antibacklash pulse width

REFA differential receiver enable

Zero delay mode

Reserved Reference selection mode Bypass REFB

REFB receiver enable

OSC_IN signal feedback for PLL1

Antibacklash

pulse width control

REFA receiver enable

ZD_IN singleended receiver mode enable (CMOS mode)

Input REFA, REFB receiver powerdown control enable

ZD_IN differen. receiver mode enable

Rev. B | Page 39 of 56

address increment

PLL1 charge pump mode 0x00

OSC_IN single-ended receiver mode enable (CMOS mode)

REFB single-ended receiver mode enable (CMOS mode)

R divider

(LSB) Bit 0

SDO active 0x00 0x000

active registers

(MSB)

OSC_IN differential receiver mode enable

REFA single-ended receiver mode enable (CMOS mode)

Bypass REFA R divider

Default Value (Hex)

0x00

AD9523

Addr (Hex)

0x01D PLL1 loop

(MSB) Bit 7

Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1

Reserved Reserved Reserved Reserved PLL1 loop filter, R

(LSB) Bit 0

0x00

ZERO

filter zero resistor control

Output PLL (PLL2)

0x0F0 PLL2 charge

PLL2 charge pump control 0x00

pump control

0x0F1 PLL2

A counter B counter 0x04 feedback N divider control

0x0F2 PLL2 control PLL2 lock

detector powerdown

0x0F3 VCO control Reserved Reserved Reserved Force release

Reserved Enable

frequency doubler

Enable SPI control of antibacklash pulse width

of distribution sync when PLL2 is

Antibacklash

pulse width control

Treat reference as valid

Force VCO to midpoint frequency

PLL2 charge pump mode 0x03

Calibrate VCO

Reserved 0x00 (not autoclearing)

unlocked

0x0F4 VCO divider

control

Reserved Reserved Reserved Reserved VCO

divider

VCO divider 0x00

powerdown

0x0F5 PLL2 loop

Pole 2 resistor (R

) Zero resistor (R

POLE2

) Pole 1 capacitor (C

ZERO

) 0x00

POLE1

filter control

0x0F6 (9 bits) Reserved Reserved Reserved Reserved Reserved Reserved Reserved Bypass internal

resistor

ZERO

0x0F9 Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved 0x00

Clock Distribution

0x190 Channel 0

control

Invert divider output

Ignore sync

Power down channel

Lower power mode

Driver mode 0x00

0x191 10-bit channel divider[7:0] (LSB) 0x1F 0x192 Divider phase[5:0] 10-bit channel divider[9:8] (MSB) 0x04 0x193 Channel 1

control

Invert divider output

Ignore sync

Power down channel

Lower power mode

Driver mode 0x20

0x194 10-bit channel divider[7:0] (LSB) 0x1F 0x195 Divider phase[5:0] 10-bit channel divider[9:8] (MSB) 0x04 0x196 Channel 2

control

Invert divider output

Ignore sync

Power down channel

Lower power mode

Driver mode 0x00

0x197 10-bit channel divider[7:0] (LSB) 0x1F 0x198 Divider phase[5:0] 10-bit channel divider[9:8] (MSB) 0x04 0x199 Channel 3

control

Invert divider output

Ignore sync

Power down channel

Lower power mode

Driver mode 0x20

0x19A 10-bit channel divider[7:0] (LSB) 0x1F 0x19B Divider phase[5:0] 10-bit channel divider[9:8] (MSB) 0x04 0x19C Channel 4

control

Invert divider output

Ignore sync

Power down channel

Lower power mode

Driver mode 0x00

0x19D 10-bit channel divider[7:0] (LSB) 0x1F 0x19E Divider phase[5:0] 10-bit channel divider[9:8] (MSB) 0x04 0x19F Channel 5

control

Invert divider output

Ignore sync

Power down channel

Lower power mode

Driver mode 0x20

0x1A0 10-bit channel divider[7:0] (LSB) 0x1F 0x1A1 Divider phase[5:0] 10-bit channel divider[9:8] (MSB) 0x04

Default Value (Hex)

0x00

Rev. B | Page 40 of 56

AD9523

Addr (Hex)

0x1A2 Channel 6

0x1A3 10-bit channel divider[7:0] (LSB) 0x1F 0x1A4 Divider phase[5:0] 10-bit channel divider[9:8] (MSB) 0x04 0x1A5 Channel 7

0x1A6 10-bit channel divider[7:0] (LSB) 0x1F 0x1A7 Divider phase[5:0] 10-bit channel divider[9:8] (MSB) 0x04 0x1A8 Channel 8

0x1A9 10-bit channel divider[7:0] (LSB) 0x1F 0x1AA Divider phase[5:0] 10-bit channel divider[9:8] (MSB) 0x04 0x1AB Channel 9

0x1AC 10-bit channel divider[7:0] (LSB) 0x1F 0x1AD Divider phase[5:0] 10-bit channel divider[9:8] (MSB) 0x04 0x1AE Channel 10

0x1AF 10-bit channel divider[7:0] (LSB) 0x1F 0x1B0 Divider phase[5:0] 10-bit channel divider[9:8] (MSB) 0x04 0x1B1 Channel 11

0x1B2 10-bit channel divider[7:0] (LSB) 0x1F 0x1B3 Divider phase[5:0] 10-bit channel divider[9:8] (MSB) 0x04 0x1B4 Channel 12

0x1B5 10-bit channel divider[7:0] (LSB) 0x1F 0x1B6 Divider phase[5:0] 10-bit channel divider[9:8] (MSB) 0x04 0x1B7 Channel 13

0x1B8 10-bit channel divider[7:0] (LSB) 0x1F 0x1B9 Divider phase[5:0] 10-bit channel divider[9:8] (MSB) 0x04 0x1BA PLL1 output

0x1BB PLL1 output

Readback

0x22C Readback 0 Status

0x22D Readback 1 Reserved Reserved Reserved Reserved Holdover

0x22E Readback 2 Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved 0x22F Readback 3 Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved

control

channel control

(MSB) Bit 7

Invert divider output

Reserved Reserved Reserved PLL1 output

PLL1 output driver powerdown

PLL2 reference clock

Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1

Ignore sync

Reserved Reserved Reserved Route

Status PLL2 feedback clock

Power down channel

Status VCXO

Lower power mode

CMOS driver strength

Status REF_TEST

VCXO clock to Ch 3 divider input

Status REFB

active

(LSB) Bit 0

Driver mode 0x00

Driver mode 0x20

Driver mode 0x00

Driver mode 0x20

Driver mode 0x00

Driver mode 0x20

Driver mode 0x00

Driver mode 0x20

Out PLL1 output 0x00

Route VCXO clock to Ch 2 divider input

Status REFA

Selected reference (in auto mode)

Route VCXO clock to Ch 1 divider input

Lock detect PLL2

Reserved VCO

Route VCXO clock to Ch 0 divider input

Lock detect PLL1

calibration in progress

Default Value (Hex)

0x80

Rev. B | Page 41 of 56

AD9523

Addr (Hex)

Other

0x230 Reserved Reserved Status Monitor 0 control 0x00 0x231 Reserved Reserved Status Monitor 1 control 0x00 0x232

0x233 Power-down

0x234 Update all

EEPROM Buffer

0xA00 Instruction (data)[7:0] (serial port configuration register) 0x00

0xA01 High byte of register address (serial port configuration register) 0x00

0xA02

0xA03 Instruction (data)[7:0] (reaback control register) 0x02

0xA04 High byte of register address (reaback control register) 0x00

0xA05

0xA06 Instruction (data)[7:0] (PLL segment) 0x0E

0xA07 High byte of register address (PLL segment) 0x00

0xA08

0xA09 Instruction (data)[7:0] (PECL/CMOS output segment) 0x0E

0xA0A High byte of register address (PECL/CMOS output segment) 0x00

0xA0B

0xA0C Instruction (data)[7:0] (divider segment) 0x2B

0xA0D High byte of register address (divider segment) 0x01

0xA0E

0xA0F Instruction (data)[7:0] (clock input and REF segment) 0x01

0xA10 High byte of register address (clock input and REF segment) 0x01

0xA11

0xA12 Instruction (data)[7:0] (other segment) 0x03

0xA13 High byte of register address (other segment) 0x02

0xA14

0xA15 EEPROM

Status signals

control

registers

EEPROM Buffer Segment Register 1 to EEPROM Buffer Segment Register 3

EEPROM Buffer Segment Register 4 to EEPROM Buffer Segment Register 6

EEPROM Buffer Segment Register 7 to EEPROM Buffer Segment Register 9

EEPROM Buffer Segment Register 10 to EEPROM Buffer Segment Register 12

EEPROM Buffer Segment Register 13 to EEPROM Buffer Segment Register 15

EEPROM Buffer Segment Register 16 to EEPROM Buffer Segment Register 18

EEPROM Buffer Segment Register 19 to EEPROM Buffer Segment Register 21

Buffer Segment Register 22

(MSB) Bit 7

Reserved Reserved Reserved Enable Status_

Reserved Reserved Reserved Reserved Reserved PLL1

Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1

EEPROM on STATUS0 pin

Reserved IO_Update 0x00

Low byte of register address (serial port configuration register) 0x00

Low byte of register address (reaback control register) 0x04

Low byte of register address (PLL segment) 0x10

Low byte of register address (PECL/CMOS output segment) 0xF0

Low byte of register address (divider segment) 0x90

Low byte of register address (clock input and REF segment) 0xE0

Low byte of register address (other segment) 0x30

STATUS1 pin divider enable

I/O update 0x80

STATUS0 pin divider enable

powerdown

(LSB)

Bit 0

Reserved Sync dividers

PLL2 power-down

(manual

control)

0: sync signal

inactive

1: dividers

held in sync

(same as

SYNC

pin low)

Distribution

power-down

Default Value (Hex)

0x00

0x07

Rev. B | Page 42 of 56

AD9523

Addr (Hex)

0xA16 EEPROM

EEPROM Control

0xB00 Status_

0xB01 EEPROM error

0xB02 EEPROM

0xB03 EEPROM

Buffer Segment Register 23

EEPROM (read only)

checking readback (read only)

Control 1

Control 2

(MSB) Bit 7

Reserved Reserved Reserved Reserved Reserved Reserved Reserved Status_

Reserved Reserved Reserved Reserved Reserved Reserved Reserved EEPROM

Reserved Reserved Reserved Reserved Reserved Reserved Soft_EEPROM Enable

Reserved Reserved Reserved Reserved Reserved Reserved Reserved REG2EEPROM 0x00

Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1

End of data 0xFF

(LSB) Bit 0

EEPROM (read only)

data error (read only)

EEPROM write

Default Value (Hex)

0x00

Rev. B | Page 43 of 56

AD9523

CONTROL REGISTER MAP BIT DESCRIPTIONS

Serial Port Configuration (Address 0x000 to Address 0x006)

Table 31. SPI Mode Serial Port Configuration

Address Bits Bit Name Description

0x000

0x004 0

Table 32. I

Address Bits Bit Name Description

0x000

0x004 0

7 SDO active Selects unidirectional or bidirectional data transfer mode. This bit is ignored in I2C mode.

0: SDIO pin used for write and read; SDO is high impedance (default). 1: SDO used for read; SDIO used for write; unidirectional mode.

LSB first/ address increment

5 Soft reset Soft reset.

4 Reserved Reserved. [3:0] Mirror[7:4]

Read back active registers

C Mode Serial Port Configuration

[7:6] Reserved Reserved. 5 Soft reset Soft reset.

4 Reserved Reserved. [3:0] Mirror[7:4] Bits[3:0] should always mirror Bits[7:4]. Set bits as follows:

Read back active registers

SPI MSB or LSB data orientation. This bit is ignored in I2C mode. 0: data-oriented MSB first; addressing decrements (default). 1: data-oriented LSB first; addressing increments.

1 (self clearing): soft reset; restores default values to internal registers.

Bits[3:0] should always mirror Bits[7:4] so that it does not matter whether the part is in MSB first or LSB first mode (see Register 0x000, Bit 6). Set bits as follows:

Bit 0 = Bit 7. Bit 1 = Bit 6. Bit 2 = Bit 5. Bit 3 = Bit 4.

For buffered registers, serial port readback reads from actual (active) registers instead of from the buffer. 0 (default): reads values currently applied to the internal logic of the device. 1: reads buffered values that take effect on the next assertion of the I/O update.

1 (self clearing): soft reset; restores default values to internal registers.

Bit 0 = Bit 7. Bit 1 = Bit 6. Bit 2 = Bit 5. Bit 3 = Bit 4.

Table 33. EEPROM Customer Version ID

Address Bits Bit Name Description

0x005 [7:0]

0x006 [7:0]

EEPROM customer version ID (LSB)

EEPROM customer version ID (MSB)

16-bit EEPROM ID, Bits[7:0]. This register, along with Register 0x006, allows the user to store a unique ID to identify which version of the AD9523 register settings is stored in the EEPROM. It does not affect AD9523 operation in any way (default: 0x00).

16-bit EEPROM ID, Bits[15:8]. This register, along with Register 0x005, allows the user to store a unique ID to identify which version of the AD9523 register settings is stored in the EEPROM. It does not affect AD9523 operation in any way (default: 0x00).

Rev. B | Page 44 of 56

AD9523

Input PLL (PLL1) (Address 0x010 to Address 0x01D)

Table 34. PLL1 REFA R Divider Control

Address Bits Bit Name Description

0x010 [7:0] REFA R divider

0x011 [1:0] 10-bit REFA R divider, Bits[9:8] (MSB)

Table 35. PLL1 REFB R Divider Control1

Address Bits Bit Name Description

0x012 [7:0] REFB R divider

0x013 [1:0] 10-bit REFB R divider, Bits[9:8] (MSB)

Requires Register 0x01C, Bit 7 = 1 for division that is independent of REFA division.

Table 36. PLL1 Reference Test Divider

Address Bits Bit Name Description

[7:6] Reserved Reserved 0x014 [5:0] REF_TEST divider

Table 37. PLL1 Reserved

Address Bits Bit Name Description

0x015 [7:0] Reserved Reserved

10-bit REFA R divider, Bits[7:0] (LSB). Divide-by-1 to divide-by-1023. 00000000, 00000001: divide-by-1.

10-bit REFB R divider, Bits[7:0] (LSB). Divide-by-1 to divide-by-1023. 00000000, 00000001: divide-by-1.

6-bit reference test divider. Divide-by-1 to divide-by-63. 000000, 000001: divide-by-1.

Table 38. PLL1 Feedback N Divider Control

Address Bits Bit Name Description

0x016

0x017 [1:0]

[7:0]

PLL1 feedback N divider control (N_PLL1)

10-bit feedback divider, Bits[7:0] (LSB). Divide-by-1 to divide-by-1023. 00000000, 00000001: divide-by-1.

10-bit feedback divider, Bits[1:0] (MSB)

Table 39. PLL1 Charge Pump Control

Address Bits Bit Name Description

7 PLL1 charge pump tristate Tristates the PLL1 charge pump. 0x018

0x019

[6:0] PLL1 charge pump control

[7:5] Reserved Reserved. 4

[3:2] Antibacklash pulse width control Controls the PFD antibacklash period.

[1:0] PLL1 charge pump mode Controls the mode of the PLL1 charge pump.

Enable SPI control of antibacklash pulse width

These bits set the magnitude of the PLL1 charge pump current. Granularity is ~0.5 A with a full-scale magnitude of ~63.5 A.

Controls the functionality of Register 0x019, Bits[3:2]. 0 (default): the device automatically controls the antibacklash period. 1: antibacklash period defined by Register 0x019, Bits[3:2].

00 (default): minimum. 01: low. 10: high. 11: maximum.

These bits are ineffective unless Register 0x019, Bit 4 = 1.

00: tristate. 01: pump up. 10: pump down. 11 (default): normal.

Rev. B | Page 45 of 56

AD9523

Table 40. PLL1 Input Receiver Control

Address Bits Bit Name Description

0x01A

7 REF_TEST input receiver enable

6 REFB differential receiver enable

5 REFA differential receiver enable

4 REFB receiver enable

3 REFA receiver enable

Input REFA and REFB receiver power-down control enable

single-ended receiver

OSC_IN mode enable (CMOS mode)

OSC_IN differential receiver mode enable

1: enabled. 0: disabled (default).

1: differential receiver mode. 0: single-ended receiver mode (also depends on Register 0x01B, Bit 1) (default).

1: differential receiver mode. 0: single-ended receiver mode (also depends on Register 0x01B, Bit 0) (default).

REFB receiver power-down control mode only when Bit 2 = 1. 1: enable REFB receiver. 0: power-down (default).

REFA receiver power-down control mode only when Bit 2 = 1. 1: enable REFA receiver. 0: power-down (default).

Enables control over power-down of the input receivers, REFA and REFB. 1: power-down control enabled. 0: both receivers enabled (default).

Selects which single-ended input pin is enabled when in the single-ended receiver mode (Register 0x01A, Bit 0 = 0). 1: negative receiver from oscillator input (OSC_IN 0: positive receiver from oscillator input (OSC_IN pin) selected (default).

1: differential receiver mode. 0: single-ended receiver mode (also depends on Bit 1) (default).

pin) selected.

Table 41. REF_TEST, REFA, REFB, and ZD_IN Control

Address Bits Bit Name Description

0x01B

7 Bypass REF_TEST divider

6 Bypass feedback divider

5 Zero delay mode

4 OSC_IN signal feedback for PLL1

single-ended receiver

ZD_IN mode enable (CMOS mode)

ZD_IN differential receiver mode enable

single-ended receiver mode

REFB enable (CMOS mode)

REFA single-ended receiver mode enable (CMOS mode)

Puts the divider into bypass mode (same as programming the divider word to 0 or 1). 1: divider in bypass mode (divide = 1). 0: divider normal operation.

Selects the zero delay mode used (via the ZD_IN pin) when Register 0x01B, Bit 4 = 0. Otherwise, this bit is ignored. 1: internal zero delay mode. The zero delay receiver is powered down. The internal zero delay path from Distribution Divider Channel 0 is used. 0: external zero delay mode. The ZD_IN receiver is enabled.

Controls the input PLL feedback path, local feedback from the OSC_IN receiver or zero delay mode. 1: OSC_IN receiver input used for the input PLL feedback (non-zero delay mode). 0: zero delay mode enabled (also depends on Register 0x01B, Bit 5 to select the zero delay path.

Selects which single-ended input pin is enabled when in the single-ended receiver mode (Register 0x01B, Bit 2 = 0). 1: ZD_IN 0: ZD_IN pin enabled.

1: differential receiver mode. 0: single-ended receiver mode (also depends on Register 0x01B, Bit 3).

Selects which single-ended input pin is enabled when in single-ended receiver mode (Register 0x01A, Bit 6 = 0). 1: REFB 0: REFB pin enabled.

Selects which single-ended input pin is enabled when in single-ended receiver mode (Register 0x01A, Bit 5 = 0). 1: REFA 0: REFA pin enabled.

pin enabled.

Rev. B | Page 46 of 56

AD9523

Table 42. PLL1 Miscellaneous Control

Address Bits Bit Name Description

0x01C

X = don’t care.

Enable REFB R divider independent division control

1: REFB R divider is controlled by Register 0x012 and Register 0x013. 0: REFB R divider is set to the same setting as the REFA R divider (Register 0x010

and Register 0x011). This requires that, for the loop to stay locked, the REFA and REFB input frequencies must be the same.

OSC_CTRL control voltage to VCC/2 when reference clock fails

High permits the OSC_CTRL control voltage to be forced to midsupply when the feedback or input clocks fail. Low tristates the charge pump output.

1: OSC_CTRL control voltage goes to VCC/2. 0: OSC_CTRL control voltage tracks the tristated (high impedance) charge pump

(through the buffer). 5 Reserved Reserved. [4:2] Reference selection mode

Programs the REFA, REFB mode selection (default = 000).

REF_SEL

Bit 4 Bit 3 Bit 2 Description

X1 0 0 0 Nonrevertive: stay on REFB.

X1 0 0 1 Revert to REFA.

X1 0 1 0 Select REFA.

X1 0 1 1 Select REFB.

0 1 X1 XX1 REF_SEL pin = 0 (low): REFA.

1 1 X

XX1 REF_SEL pin = 1 (high): REFB.

1 Bypass REFB R divider Puts the divider into bypass mode (same as programming divider word to 0 or 1).

1: divider in bypass mode (divide = 1).

0: divider normal operation. 0 Bypass REFA R divider Puts the divider into bypass mode (same as programming divider word to 0 or 1).

1: divider in bypass mode (divide = 1).

0: divider normal operation.

Table 43. PLL1 Loop Filter Zero Resistor Control

Address Bits Bit Name Description

0x01D

[7:4] Reserved Reserved. [3:0] PLL1 loop filter, R

Programs the value of the zero resistor, R

ZERO

Bit 3 Bit 2 Bit 1 Bit 0 R

0 0 0 0 883 0 0 0 1 677 0 0 1 0 341 0 0 1 1 135 0 1 0 0 10 0 1 0 1 10 0 1 1 0 10 0 1 1 1 10 1 0 0 0 Use external resistor

ZERO

Value (kΩ )

Rev. B | Page 47 of 56

AD9523

Output PLL (PLL2) (Address 0x0F0 to Address 0x0F6)

Table 44. PLL2 Charge Pump Control

Address Bits Bit Name Description

0x0F0 [7:0] PLL2 charge pump control

Table 45. PLL2 Feedback N Divider Control

Address Bits Bit Name Description

0x0F1

[7:6] A counter A counter word. [5:0] B counter B counter word.

A Counter (Bits[7:6])

A = 0 or A = 1 B = 4 16, 17 A = 0 to A = 2 B = 5 20, 21, 22 A = 0 to A = 2 B = 6 24, 25, 26 A = 0 to A = 3

Table 46. PLL2 Control

Address Bits Bit Name Description

0x0F2

7 PLL2 lock detector power-down

6 Reserved Default = 0; value must remain 0. 5 Enable frequency doubler

Enable SPI control of antibacklash pulse width

[3:2] Antibacklash pulse width control

[1:0] PLL2 charge pump mode

These bits set the magnitude of the PLL2 charge pump current. Granularity is ~3.5 A with a full-scale magnitude of ~900 A.

Feedback Divider Constraints

B Counter (Bits[5:0]) Allowed N Division (4 × B + A)

B ≥ 7 28, 29 … continuous to 255

Controls power-down of the PLL2 lock detector. 1: lock detector powered down. 0: lock detector active.

Enables doubling of the PLL2 reference input frequency. 1: enabled. 0: disabled.

Controls the functionality of Register 0x0F2, Bits[3:2]. 0 (default): device automatically controls the antibacklash period. 1: antibacklash period defined by Register 0x0F2, Bits[3:2].

Controls the PFD antibacklash period of PLL2. 00 (default): minimum. 01: low. 10: high. 11: maximum. These bits are ineffective unless Register 0x0F2, Bit 4 = 1.

Controls the mode of the PLL2 charge pump: 00: tristate. 01: pump up. 10: pump down. 11 (default): normal.

Table 47. VCO Control

Address Bits Bit Name Description

0x0F3

[7:5] Reserved Reserved. 4

Force release of distribution sync when PLL2 is unlocked

0 (default): distribution is held in sync (static) until the output PLL locks. Then it is automatically released from sync with all dividers synchronized. 1: overrides the PLL2 lock detector state; forces release of the distribution from sync.

3 Treat reference as valid

0 (default): uses the PLL1 VCXO indicator to determine when the reference clock to the PLL2 is valid. 1: treats the reference clock as valid even if PLL1 does not consider it to be valid.

Force VCO to midpoint frequency

Selects VCO control voltage functionality. 0 (default): normal VCO operation. 1: forces VCO control voltage to midscale.

Calibrate VCO (not autoclearing)

1: initiates VCO calibration (this is not an autoclearing bit). 0: resets the VCO calibration.

0 Reserved Reserved.

Rev. B | Page 48 of 56

AD9523

Table 48. VCO Divider Control

Address Bits Bit Name Description

0x0F4

Table 49. PLL2 Loop Filter Control

Address Bits Bit Name Description

0x0F5

[7:4] Reserved Reserved. 3 VCO divider power-down

1: powers down the divider. 0: normal operation.

[2:0] VCO divider

Note that the VCO divider connects to all output channels.

Bit 2 Bit 1 Bit 0 Divider Value

0 0 0 Divide-by-4 0 0 1 Divide-by-5 0 1 0 Divide-by-6 0 1 1 Divide-by-7 1 0 0 Divide-by-8 1 0 1 Divide-by-9 1 1 0 Divide-by-10 1 1 1 Divide-by-11

[7:6] Pole 2 resistor (R

POLE2

)

Bit 7 Bit 6

0 0 900 0 1 450 1 0 300 1 1

[5:3] Zero resistor (R

ZERO

)

Bit 5 Bit 4 Bit 3 0 0 0 3250 0 0 1 2750 0 1 0 2250 0 1 1 2100 1 0 0 3000 1 0 1 2500 1 1 0 2000 1 1 1 1850

[2:0] Pole 1 capacitor (C

POLE1

)

Bit 2 Bit 1 Bit 0

0 0 0 0 0 0 1 8 0 1 0 16 0 1 1 24 1 0 0 24 1 0 1 32 1 1 0 40

1 1 1 48 [7:1] Reserved Reserved. 0x0F6 0

Bypass internal R resistor

ZERO

Bypasses the internal R

resistor. This bit is the MSB of the loop filter control register (Address 0x0F5 and Address 0x0F6).

POLE2

(Ω)

225

ZERO

(Ω)

POLE1

(pF)

resistor (R

ZERO

= 0 Ω). Requires the use of a series external zero

ZERO

Rev. B | Page 49 of 56

AD9523

Clock Distribution (Register 0x190 to Register 0x1B9)

Table 50. Channel 0 to Channel 13 Control (This Same Map Applies to All 14 Channels)

Address Bits Bit Name Description

0x190

0x191 [7:0]

0x192 [7:2] Divider phase

[1:0] Channel divider, Bits[9:8] (MSB) 10-bit channel divider, Bits[9:8] (MSB).

7 Invert divider output Inverts the polarity of the divider’s output clock. 6 Ignore sync

5 Power down channel

Lower power mode (differential modes only)

[3:0] Driver mode

Channel divider, Bits[7:0] (LSB)

0: obeys chip-level SYNC signal (default). 1: ignores chip-level SYNC signal.

1: powers down the entire channel. 0: normal operation.

Reduces power used in the differential output modes (LVDS/LVPECL/HSTL). This reduction may result in power savings, but at the expense of performance. Note that this bit does not affect output swing and current, just the internal driver power. 1: low strength/lower power. 0: normal operation.

Driver mode.

Bit 3 Bit 2 Bit 1 Bit 0 Driver Mode

0 0 0 0 Tristate output 0 0 0 1 LVPECL (8 mA) 0 0 1 0 LVDS (3.5 mA) 0 0 1 1 LVDS (7 mA) 0 1 0 0 HSTL-0 (16 mA) 0 1 0 1 HSTL-1 (8 mA) 0 1 1 0

0 1 1 1

1 0 0 0

1 0 0 1

1 0 1 0

1 0 1 1

1 1 0 0

1 1 0 1

1 1 1 0

1 1 1 1 Tristate output Division = Channel Divider Bits[9:0] + 1. For example, [9:0] = 0 is divided by 1, [9:0] = 1

is divided by 2 … [9:0] = 1023 is divided by 1024. 10-bit channel divider, Bits[7:0] (LSB). Divider initial phase after a sync is asserted relative to the divider input clock (from the

VCO divider output). LSB = ½ of a period of the divider input clock. Phase = 0: no phase offset. Phase = 1: ½ period offset, … Phase = 63: 31 period offset.

CMOS (both outputs in phase) + Pin: true phase relative to divider output

− Pin: true phase relative to divider output CMOS (opposite phases on outputs)

+ Pin: true phase relative to divider output

− Pin: complement phase relative to divider output CMOS

+ Pin: true phase relative to divider output

− Pin: high-Z CMOS

+ Pin: high-Z

− Pin: true phase relative to divider output CMOS

+ Pin: high-Z

− Pin: high-Z CMOS (both outputs in phase)

+ Pin: complement phase relative to divider output

− Pin: complement phase relative to divider output CMOS (both outputs out of phase)

+ Pin: complement phase relative to divider output

− Pin: true phase relative to divider output CMOS

+ Pin: complement phase relative to divider output

− Pin: high-Z CMOS

+ Pin: high-Z

− Pin: complement phase relative to divider output

Rev. B | Page 50 of 56

AD9523

Table 51. PLL1 Output Control (PLL1_OUT, Pin 72)

Address Bits Bit Name Description

0x1BA

Table 52. PLL1 Output Channel Control

Address Bits Bit Name Description

0x1BB

[7:5] Reserved Reserved 4

PLL1 output CMOS driver strength

[3:0] PLL1 output divider

7 PLL1 output driver power-down PLL1 output driver power-down [6:4] Reserved Reserved 3

Route VCXO clock to Channel 3 divider input

Route VCXO clock to Channel 2 divider input

Route VCXO clock to Channel 1 divider input

Route VCXO clock to Channel 0 divider input

CMOS driver strength 1: weak 0: strong

0000: divide-by-1 0001: divide-by-2 (default) 0010: divide-by-4 0100: divide-by-8 1000: divide-by-16 No other inputs permitted

1: channel uses VCXO clock. Routes VCXO clock to divider input. 0: channel uses VCO divider output clock

Readback (Address 0x22C to Address 0x22D)

Table 53. Readback Registers (Readback 0 and Readback 1)

Address Bits Bit Name Description

0x22C

0x22D

7 Status PLL2 reference clock

6 Status PLL2 feedback clock

5 Status VCXO

4 Status REF_TEST

3 Status REFB

2 Status REFA

1 Lock detect PLL2

0 Lock detect PLL1

[7:4] Reserved Reserved 3 Holdover active

Selected reference (in auto mode)

1 Reserved Reserved 0 VCO calibration in progress

1: OK 0: off/clocks are missing

1: locked 0: unlocked

1: holdover is active (both references are missing) 0: normal operation

Selected reference (applies only when the device automatically selects the reference; for example, not in manual control mode) 1: REFB 0: REFA

1: VCO calibration in progress 0: VCO calibration not in progress

Rev. B | Page 51 of 56

AD9523

Other (Address 0x230 to Address 0x234)

Table 54. Status Signals

Address Bits Bit Name Description

0x230

[7:6] Reserved Reserved [5:0] Status Monitor 0 control

Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Muxout

0 0 0 0 0 0 GND 0 0 0 0 0 1 PLL1 and PLL2 locked 0 0 0 0 1 0 PLL1 locked 0 0 0 0 1 1 PLL2 locked 0 0 0 1 0 0 Both references are missing (REFA and REFB) 0 0 0 1 0 1 Both references are missing and PLL2 is locked 0 0 0 1 1 0 REFB selected (applies only to auto select mode) 0 0 0 1 1 1 REFA is OK 0 0 1 0 0 0 REFB is OK 0 0 1 0 0 1 REF_TEST is OK 0 0 1 0 1 0 VCXO is OK 0 0 1 0 1 1 PLL1 feedback is OK 0 0 1 1 0 0 PLL2 reference clock is OK 0 0 1 1 0 1 Reserved 0 0 1 1 1 0 REFA and REFB are OK 0 0 1 1 1 1 All clocks are OK (except REF_TEST) 0 1 0 0 0 0 PLL1 feedback is divide-by-2 0 1 0 0 0 1 PLL1 PFD down divide-by-2 0 1 0 0 1 0 PLL1 REF divide-by-2 0 1 0 0 1 1 PLL1 PFD up divide-by-2 0 1 0 1 0 0 GND 0 1 0 1 0 1 GND 0 1 0 1 1 0 GND 0 1 0 1 1 1 GND

Note that all bit combinations after 010111 are reserved.

Rev. B | Page 52 of 56

AD9523

Address Bits Bit Name Description

0x231

0x232

[7:6] Reserved Reserved [5:0] Status Monitor 1 control

[7:5] Reserved Reserved. 4

Enable Status_EEPROM on STATUS0 pin

STATUS1 pin divider enable

STATUS0 pin divider enable

1 Reserved Reserved. 0

Sync dividers (manual control)

Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Muxout

0 0 0 0 0 0 GND 0 0 0 0 0 1 PLL1 and PLL2 locked 0 0 0 0 1 0 PLL1 locked 0 0 0 0 1 1 PLL2 locked 0 0 0 1 0 0 Both references are missing (REFA and REFB) 0 0 0 1 0 1 Both references are missing and PLL2 is locked 0 0 0 1 1 0 REFB selected (applies only to auto select mode) 0 0 0 1 1 1 REFA is OK 0 0 1 0 0 0 REFB is OK 0 0 1 0 0 1 REF_TEST is OK 0 0 1 0 1 0 VCXO is OK 0 0 1 0 1 1 PLL1 feedback is OK 0 0 1 1 0 0 PLL2 reference clock is OK 0 0 1 1 0 1 Reserved 0 0 1 1 1 0 REFA and REFB are OK 0 0 1 1 1 1 All clocks are OK (except REF_TEST) 0 1 0 0 0 0 GND 0 1 0 0 0 1 GND 0 1 0 0 1 0 GND 0 1 0 0 1 1 GND 0 1 0 1 0 0 PLL2 feedback is divide-by-2 0 1 0 1 0 1 PLL2 PFD down divide-by-2 0 1 0 1 1 0 PLL2 REF divide-by-2 0 1 0 1 1 1 PLL2 PFD up divide-by-2

Enables the EEPROM status on the STATUS0 pin. 1: enable status.

Enables a divide-by-4 on the STATUS1 pin, allowing dynamic signals to be viewed at a lower frequency (such as the PFD input clocks). Not to be used with dc states on the status pins, which occur when the settings of Register 0x231, Bits[5:0] are in the range of 000000 to 001111. 1: enabled. 0: disabled.

Enables a divide-by-4 on the STATUS0 pin, allowing dynamic signals to be viewed at a lower frequency (such as the PFD input clocks). Not to be used with dc states on the status pins, which occur when the settings of Register 0x230, Bits[5:0] are in the range of 000000 to 001111. 1: enable. 0: disable.

Set bit to put dividers in sync; clear bit to release. Functions like SYNC 1: sync.

0: normal.

Note that all bit combinations after 010111 are reserved.

pin low.

Rev. B | Page 53 of 56

AD9523

Table 55. Power-Down Control

Address Bits Bit Name Description

0x233

Table 56. Update All Registers

Address Bits Bit Name Description

EEPROM Buffer (Address 0xA00 to Address 0xA16)

Table 57. EEPROM Buffer Segment

Address Bits Bit Name Description

0xA00 to 0xA16

[7:3] Reserved Reserved. 2 PLL1 power-down

1 PLL2 power-down

Distribution powerdown

[7:1] Reserved Reserved. 0x234 0 IO_Update

[7:0]

EEPROM Buffer Segment Register 1 to EEPROM Buffer Segment Register 23

1: power-down (default). 0: normal operation.

Powers down the distribution. 1: power-down (default). 0: normal operation.

This bit must be set to 1 to transfer the contents of the buffer registers into the active registers, which happens on the next SCLK rising edge. This bit is self-clearing; that is, it does not have to be set back to 0. 1 (self-clearing): update all active registers to the contents of the buffer registers.

The EEPROM buffer segment section stores the starting address and number of bytes that are to be stored and read back to and from the EEPROM. Because the register space is noncontiguous, the EEPROM controller needs to know the starting address and number of bytes in the register space to store and retrieve from the EEPROM. In addition, there are special instructions for the EEPROM controller: operational codes (that is, IO_Update and end-of-data) that are also stored in the EEPROM buffer segment. The on-chip default setting of the EEPROM buffer segment registers is designed such that all registers are transferred to/from the EEPROM, and an IO_Update is issued after the transfer (see the Programming the EEPROM Buffer Segment section).

EEPROM Control (Address 0xB00 to Address 0xB03)

Table 58. Status_EEPROM

Address Bits Bit Name Description

[7:1] Reserved Reserved. 0xB00 0

Status_EEPROM (read only)

This read-only bit indicates the status of the data transferred between the EEPROM and the buffer register bank during the writing and reading of the EEPROM. This signal is also available at the STATUS0 pin when Register 0x232, Bit 4 is set. 0: data transfer is complete. 1: data transfer is not complete.

Table 59. EEPROM Error Checking Readback

Address Bits Bit Name Description

[7:1] Reserved Reserved. 0xB01 0

EEPROM data error (read only)

This read-only bit indicates an error during the data transfer between the EEPROM and the buffer. 0: no error; data is correct. 1: incorrect data detected.

Rev. B | Page 54 of 56

AD9523

Table 60. EEPROM Control 1

Address Bits Bit Name Description

0xB02

Table 61. EEPROM Control 2

Address Bits Bit Name Description

[7:2] Reserved Reserved. 1 Soft_EEPROM

0 Enable EEPROM write

[7:1] Reserved Reserved. 0xB03 0 REG2EEPROM

When the EEPROM_SEL pin is tied low, setting the Soft_EEPROM bit resets the AD9523 using the settings saved in EEPROM. 1: soft reset with EEPROM settings (self-clearing).

Enables the user to write to the EEPROM. 0: EEPROM write protection is enabled. User cannot write to EEPROM (default). 1: EEPROM write protection is disabled. User can write to EEPROM.

Transfers data from the buffer register to the EEPROM (self-clearing). 1: setting this bit initiates the data transfer from the buffer register to the EEPROM (writing process); it is reset by the I²C master after the data transfer is done.

Rev. B | Page 55 of 56

AD9523

OUTLINE DIMENSIONS

0.60

0.42

0.24

EXPOSED PAD

(BOTTOM VIEW)

PIN 1

INDICATOR

5.45

5.30 SQ

5.15

PIN 1

INDICATOR

10.00

BSC SQ

TOP VI EW

9.75

BSC SQ

0.60

0.42

0.24

0.50

BSC

1.00

0.85

0.80

SEATING

PLANE

12° MAX

0.50

0.40

0.30

0.80 MAX

0.65 TYP

0.30

0.23

0.18

COMPLIANT TO JEDEC STANDARDS MO-220-VNND-4

0.05 MAX

0.02 NOM

0.20 REF

COPLANARITY

0.08

8.50 REF

FOR PROPER CONNECTION OF THE EXPOSED PAD, REFER TO THE PIN CONFIGURATION AND FUNCTION DESCRIPTIONS SECTION OF THIS DATA SHEET.

052709-B

Figure 44. 72-Lead Lead Frame Chip Scale Package [LFCSP_VQ]

10 mm × 10 mm Body, Very Thin Quad

(CP-72-6)

Dimensions shown in millimeters

ORDERING GUIDE

Model1 Temperature Range Package Description Package Option

AD9523BCPZ −40°C to +85°C 72-Lead Lead Frame Chip Scale Package [LFCSP_VQ] CP-72-6 AD9523BCPZ-REEL7 −40°C to +85°C 72-Lead Lead Frame Chip Scale Package [LFCSP_VQ] CP-72-6 AD9523/PCBZ Evaluation Board

Z = RoHS Compliant Part.

I2C refers to a communications protocol originally developed by Philips Semiconductors (now NXP Semiconductors).

Rev. B | Page 56 of 56

ANALOG DEVICES AD9523 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

FEATURES

APPLICATIONS

FUNCTIONAL BLOCK DIAGRAM

GENERAL DESCRIPTION

TABLE OF CONTENTS

REVISION HISTORY

SPECIFICATIONS

CONDITIONS

SUPPLY CURRENT

POWER DISSIPATION

OSC_CTRL OUTPUT CHARACTERISTICS

REF_TEST INPUT CHARACTERISTICS

PLL1 OUTPUT CHARACTERISTICS

TIMING ALIGNMENT CHARACTERISTICS

JITTER AND NOISE CHARACTERISTICS

PLL2 CHARACTERISTICS

STATUS OUTPUT PINS—STATUS1, STATUS0

SERIAL CONTROL PORT—SPI MODE

SERIAL CONTROL PORT—I²C MODE

ABSOLUTE MAXIMUM RATINGS

THERMAL RESISTANCE

ESD CAUTION

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

TYPICAL PERFORMANCE CHARACTERISTICS

INPUT/OUTPUT TERMINATION RECOMMENDATIONS

TERMINOLOGY

THEORY OF OPERATION

DETAILED BLOCK DIAGRAM

OVERVIEW

COMPONENT BLOCKS—INPUT PLL (PLL1)

PLL1 General Description

PLL1 Reference Clock Inputs

PLL1 Loop Filter

PLL1 Input Dividers

PLL1 Reference Switchover

PLL1 Holdover

COMPONENT BLOCKS—OUTPUT PLL (PLL2)

PLL2 General Description

Input 2× Frequency Multiplier

PLL2 Feedback Divider

PLL2 Loop Filter

VCO Divider

VCO Calibration

CLOCK DISTRIBUTION

Clock Dividers

Output Power-Down

Multimode Output Drivers

Clock Distribution Synchronization

ZERO DELAY OPERATION

Internal Zero Delay Mode

External Zero Delay Mode

SERIAL CONTROL PORT

SPI/I²C PORT SELECTION

I²C SERIAL PORT OPERATION

I2C Bus Characteristics

Data Transfer Process

Data Transfer Format

I²C Serial Port Timing

SPI SERIAL PORT OPERATION

Pin Descriptions

SPI Mode Operation

Communication Cycle—Instruction Plus Data

Write

Read

SPI INSTRUCTION WORD (16 BITS)

SPI MSB/LSB FIRST TRANSFERS

EEPROM OPERATIONS

WRITING TO THE EEPROM

READING FROM THE EEPROM

PROGRAMMING THE EEPROM BUFFER SEGMENT

Register Section Definition Group

IO_Update (Operational Code 0x80)

End-of-Data (Operational Code 0xFF)

Pseudo-End-of-Data (Operational Code 0xFE)

POWER DISSIPATION AND THERMAL CONSIDERATIONS

CLOCK SPEED AND DRIVER MODE