ANALOG DEVICES AD9258 Service Manual

14-Bit, 80 MSPS/105 MSPS/125 MSPS, 1.8 V Dual
S

FEATURES

SNR = 77.6 dBFS @ 70 MHz and 125 MSPS SFDR = 88 dBc @ 70 MHz and 125 MSPS Low power: 750 mW @ 125 MSPS
1.8 V analog supply operation
1.8 V CMOS or LVDS output supply Integer 1-to-8 input clock divider IF sampling frequencies to 300 MHz
−152.8 dBm/Hz small signal input noise with 200 Ω input impedance @ 70 MHz and 125 MSPS
Optional on-chip dither Programmable internal ADC voltage reference Integrated ADC sample-and-hold inputs Flexible analog input range: 1 V p-p to 2 V p-p Differential analog inputs with 650 MHz bandwidth ADC clock duty cycle stabilizer 95 dB channel isolation/crosstalk Serial port control User-configurable, built-in self-test (BIST) capability Energy-saving power-down modes

APPLICATIONS

Communications Diversity radio systems Multimode digital receivers (3G)
GSM, EDGE, W-CDMA, LTE, CDMA2000, WiMAX, TD-SCDMA
I/Q demodulation systems Smart antenna systems General-purpose software radios Broadband data applications Ultrasound equipment
Analog-to-Digital Converter (ADC)
AD9258

FUNCTIONAL BLOCK DIAGRAM

SDIO/
SCLK/
DCS
DFS
AD9258
VIN+A VIN–A
VREF ENSE
SELECT
VCM
RBIAS
VIN–B
VIN+B
NOTES
1. PIN NAMES ARE FOR THE CMOS PIN CONFIGURATION ONLY; SEE FIGURE 7 FORLVDS PIN NAMES.
REF
MULTICHIP
ADC
ADC
SYNC
SYNCAGND
SPI
PROGRAMMI NG DATA
CMOS/LVDS
OUTPUT BUFFER
DIVIDE 1
TO 8
DUTY CYCLE
STABILIZER
CMOS/LVDS
OUTPUT BUFFER
PDWN OEB
Figure 1.

PRODUCT HIGHLIGHTS

1. On-chip dither option for improved SFDR performance
with low power analog input.
2. Proprietary differential input that maintains excellent SNR
performance for input frequencies up to 300 MHz.
3. Operation from a single 1.8 V supply and a separate digital
output driver supply accommodating 1.8 V CMOS or LVDS outputs .
4. Standard serial port interface (SPI) that supports various
product features and functions, such as data formatting (offset binary, twos complement, or gray coding), enabling the clock DCS, power-down, test modes, and voltage reference mode.
5. Pin compatibility with the AD9268, allowing a simple
migration from 14 bits to 16 bits. The AD9258 is also pin compatible with the AD9251, AD9231, and AD9204 family of products for lower sample rate, low power applications.
DRVDDCSBAVDD
DCO
GENERATION
ORA D13A (MSB)
14
TO D0A (LSB)
CLK+ CLK–
DCOA DCOB
ORB D13B (MSB)
14
TO D0B (LSB)
08124-001
Rev. A
Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other 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.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 ©2009 Analog Devices, Inc. All rights reserved.
AD9258

TABLE OF CONTENTS

Features .............................................................................................. 1
Applications ....................................................................................... 1
Functional Block Diagram .............................................................. 1
Product Highlights ........................................................................... 1
Revision History ............................................................................... 2
General Description ......................................................................... 3
Specifications ..................................................................................... 4
ADC DC Specifications ................................................................. 4
ADC AC Specifications ................................................................. 6
Digital Specifications ................................................................... 7
Switching Specifications ................................................................ 9
Timing Specifications ................................................................ 10
Absolute Maximum Ratings .......................................................... 12
Thermal Characteristics ............................................................ 12
ESD Caution ................................................................................ 12
Pin Configurations and Function Descriptions ......................... 13
Typical Performance Characteristics ........................................... 17
Equivalent Circuits ......................................................................... 25
Theory of Operation ...................................................................... 26
ADC Architecture ...................................................................... 26
Analog Input Considerations .................................................... 26
Voltage Reference ....................................................................... 29
Clock Input Considerations ...................................................... 30
Channel/Chip Synchronization ................................................ 31
Power Dissipation and Standby Mode .................................... 32
Digital Outputs ........................................................................... 32
Timing ......................................................................................... 33
Built-In Self-Test (BIST) and Output Test .................................. 34
Built-In Self-Test (BIST) ............................................................ 34
Output Test Modes ..................................................................... 34
Serial Port Interface (SPI) .............................................................. 35
Configuration Using the SPI ..................................................... 35
Hardware Interface ..................................................................... 36
Configuration Without the SPI ................................................ 36
SPI Accessible Features .............................................................. 36
Memory Map .................................................................................. 37
Reading the Memory Map Register Table ............................... 37
Memory Map Register Table ..................................................... 38
Memory Map Register Descriptions ........................................ 40
Applications Information .............................................................. 41
Design Guidelines ...................................................................... 41
Outline Dimensions ....................................................................... 42
Ordering Guide .......................................................................... 42

REVISION HISTORY

9/09—Rev. 0 to Rev. A
Changes to Features List .................................................................. 1
Changes to Specifications Section .................................................. 4
Changes to Table 5 ............................................................................ 9
Changes to Typical Performance Characteristics Section ......... 17
5/09—Revision 0: Initial Version
Rev. A | Page 2 of 44
AD9258

GENERAL DESCRIPTION

The AD9258 is a dual, 14-bit, 80 MSPS/105 MSPS/125 MSPS analog-to-digital converter (ADC). The AD9258 is designed to support communications applications where high performance, combined with low cost, small size, and versatility, is desired.
The dual ADC core features a multistage, differential pipelined architecture with integrated output error correction logic. Each ADC features wide bandwidth differential sample-and-hold analog input amplifiers that support a variety of user-selectable input ranges. An integrated voltage reference eases design consid­erations. A duty cycle stabilizer is provided to compensate for variations in the ADC clock duty cycle, allowing the converters to maintain excellent performance.
The ADC output data can be routed directly to the two external 14-bit output ports. These outputs can be set to either 1.8 V CMOS or LVDS.
Flexible power-down options allow significant power savings, when desired.
Programming for setup and control is accomplished using a 3-wire SPI-compatible serial interface.
The AD9258 is available in a 64-lead LFCSP and is specified over the industrial temperature range of −40°C to +85°C.
Rev. A | Page 3 of 44
AD9258

SPECIFICATIONS

ADC DC SPECIFICATIONS

AVDD = 1.8 V, DRVDD = 1.8 V, maximum sample rate, VIN = −1.0 dBFS differential input, 1.0 V internal reference, DCS enabled, unless otherwise noted.
Table 1.
AD9258BCPZ-80 AD9258BCPZ-105 AD9258BCPZ-125 Parameter Temperature Min Typ Max Min Typ Max Min Typ Max Unit
RESOLUTION Full 14 14 14 Bits ACCURACY
No Missing Codes Full Guaranteed Guaranteed Guaranteed Offset Error Full ±0.1 ±0.5 ±0.1 ±0.5 ±0.4 ±0.65 % FSR Gain Error Full ±0.4 ±2.5 ±0.4 ±2.5 ±0.4 ±2.5 % FSR Differential
Nonlinearity (DNL)
25°C ±0.25 ±0.25 ±0.25 LSB
Integral Nonlinearity
1
(INL) 25°C ±0.55 ±0.7 ±0.8 LSB MATCHING
CHARACTERISTIC
Offset Error Full ±0.1 ±0.4 ±0.1 ±0.4 ±0.2 ±0.45 % FSR Gain Error Full ±0.3 ±1.3 ±0.3 ±1.3 ±0.3 ±1.3 % FSR
TEMPERATURE DRIFT
Offset Error Full ±2 ±2 ±2 ppm/°C Gain Error Full ±15 ±15 ±15 ppm/°C
INTERNAL VOLTAGE REFERENCE
Output Voltage Error
(1 V Mode)
Load Regulation @
1.0 mA
INPUT REFERRED NOISE
VREF = 1.0 V 25°C 0.62 0.63 0.7
ANALOG INPUT
Input Span, VREF =
1.0 V Input Capacitance Input Common-
Mode Voltage
REFERENCE INPUT RESISTANCE
POWER SUPPLIES
Supply Voltage
AVDD Full 1.7 1.8 1.9 1.7 1.8 1.9 1.7 1.8 1.9 V DRVDD Full 1.7 1.8 1.9 1.7 1.8 1.9 1.7 1.8 1.9 V
Supply Current
1
IAVDD
Full 234 240 293 300 390 400 mA
IDRVDD1 (1.8 V
CMOS)
IDRVDD1 (1.8 V
LVD S)
Full ±0.5 ±0.5 ±0.5 LSB
1
Full ±1.1 ±1.3 ±1.4 LSB
Full ±5 ±12 ±5 ±12 ±5 ±12 mV
Full 5 5 5 mV
LSB rms
Full 2 2 2 V p-p
2
Full 8 8 8 pF
Full 0.9 0.9 0.9 V
Full 6 6 6
Full 33 43 53 mA
Full 81 81 90 mA
Rev. A | Page 4 of 44
AD9258
AD9258BCPZ-80 AD9258BCPZ-105 AD9258BCPZ-125 Parameter Temperature Min Typ Max Min Typ Max Min Typ Max Unit
POWER CONSUMPTION
DC Input Full 462 487 565 590 750 777 mW Sine Wave Input1
(DRVDD = 1.8 V CMOS Output Mode)
Sine Wave Input1
(DRVDD = 1.8 V LVDS Output Mode)
Standby Power
3
Power-Down Power Full 0.5 2.5 0.5 2.5 0.5 2.5 mW
1
Measured with a low input frequency, full-scale sine wave, with approximately 5 pF loading on each output bit.
2
Input capacitance refers to the effective capacitance between one differential input pin and AGND.
3
Standby power is measured with a dc input and with the CLK pins inactive (set to AVDD or AGND).
Full 481 605 797 mW
Full 568 671 865 mW
Full 45 45 45 mW
Rev. A | Page 5 of 44
AD9258

ADC AC SPECIFICATIONS

AVDD = 1.8 V, DRVDD = 1.8 V, maximum sample rate, VIN = −1.0 dBFS differential input, 1.0 V internal reference, DCS enabled, unless otherwise noted.
Table 2.
AD9258BCPZ-80 AD9258BCPZ-105 AD9258BCPZ-125 Parameter
SIGNAL-TO-NOISE-RATIO (SNR)
fIN = 2.4 MHz 25°C 79.0 78.4 77.7 dBFS fIN = 70 MHz 25°C 77.7 78.3 77.3 78.2 76.8 77.6 dBFS Full 77.4 76.9 76.0 dBFS
fIN = 140 MHz fIN = 200 MHz 25°C 75.3 74.9 75.1 dBFS
SIGNAL-TO-NOISE AND DISTORTION (SINAD)
fIN = 2.4 MHz 25°C 78.7 77.8 77.3 dBFS fIN = 70 MHz 25°C 77.5 78.0 77.1 78.0 76.5 77.0 dBFS Full 77.2 76.7 75.7 dBFS fIN = 140 MHz 25°C 75.1 75.6 75.3 dBFS fIN = 200 MHz 25°C 74.2 72.1 73.6 dBFS
EFFECTIVE NUMBER OF BITS (ENOB)
fIN = 2.4 MHz 25°C 12.8 12.6 12.5 Bits fIN = 70 MHz 25°C 12.7 12.6 12.5 Bits fIN = 140 MHz 25°C 12.2 12.3 12.2 Bits fIN = 200 MHz 25°C 12.0 11.7 11.9 Bits
WORST SECOND OR THIRD HARMONIC
fIN = 2.4 MHz 25°C −92 −87 −90 dBc fIN = 70 MHz 25°C −91 −87 −92 −87 −88 −83 dBc Full −87 −87 −83 dBc fIN = 140 MHz 25°C −80 −84 −83 dBc fIN = 200 MHz 25°C −82 −76 −79 dBc
SPURIOUS-FREE DYNAMIC RANGE (SFDR)
fIN = 2.4 MHz 25°C 92 87 90 dBc fIN = 70 MHz 25°C 87 91 87 92 83 88 dBc Full 87 87 83 dBc fIN = 140 MHz 25°C 80 84 83 dBc fIN = 200 MHz 25°C 82 76 79 dBc
SPURIOUS-FREE DYNAMIC RANGE (SFDR)
Without Dither (AIN @ −23 dBFS)
With On-Chip Dither (AIN @ −23 dBFS)
1
Temp Min Typ Max Min Typ Max Min Typ Max Unit
25°C 77.0 76.6 76.6 dBFS
fIN = 2.4 MHz 25°C 93 100 88 dBFS fIN = 70 MHz 25°C 95 96 89 dBFS fIN = 140 MHz 25°C 98 96 90 dBFS fIN = 200 MHz 25°C 102 100 89 dBFS
fIN = 2.4 MHz 25°C 107 106 107 dBFS fIN = 70 MHz 25°C 106 107 106 dBFS fIN = 140 MHz 25°C 106 105 103 dBFS fIN = 200 MHz 25°C 105 106 105 dBFS
Rev. A | Page 6 of 44
AD9258
AD9258BCPZ-80 AD9258BCPZ-105 AD9258BCPZ-125 Parameter
WORST OTHER (HARMONIC OR SPUR)
Without Dither
With On-Chip Dither
TWO-TONE SFDR WITHOUT DITHER
fIN = 29 MHz (−7 dBFS ), 32 MHz (−7 dBFS ) 25°C 93 92 90 dBc
fIN = 169 MHz (−7 dBFS ),172 MHz (−7 dBFS ) 25°C 81 80 82 dBc CROSSTALK ANALOG INPUT BANDWIDTH 25°C 650 650 650 MHz
1
See the AN-835 Application Note, Understanding High Speed ADC Testing and Evaluation, for a complete set of definitions.
2
Crosstalk is measured at 100 MHz with −1.0 dBFS on one channel and no input on the alternate channel.
1
Temp Min Typ Max Min Typ Max Min Typ Max Unit
fIN = 2.4 MHz 25°C −100 −100 −99 dBc fIN = 70 MHz 25°C −100 −96 −99 −94 −98 −94 dBc Full −96 −94 −94 dBc fIN = 140 MHz 25°C −97 −97 −97 dBc fIN = 200 MHz 25°C −95 −95 −95 dBc
fIN = 2.4 MHz 25°C −109 −107 −107 dBc fIN = 70 MHz 25°C −105 −96 −106 −95 −105 −95 dBc Full −96 −95 −95 dBc fIN = 140 MHz 25°C −106 −104 −103 dBc fIN = 200 MHz 25°C −102 −104 −97 dBc
2
Full −95 −95 −95 dB

DIGITAL SPECIFICATIONS

AVDD = 1.8 V, DRVDD = 1.8 V, maximum sample rate, VIN = −1.0 dBFS differential input, 1.0 V internal reference, and DCS enabled, unless otherwise noted.
Table 3.
Parameter Temperature Min Typ Max Unit
DIFFERENTIAL CLOCK INPUTS (CLK+, CLK−)
Logic Compliance CMOS/LVDS/LVPECL
Internal Common-Mode Bias Full 0.9 V
Differential Input Voltage Full 0.3 3.6 V p-p
Input Voltage Range Full AGND AVDD V
Input Common-Mode Range Full 0.9 1.4 V
High Level Input Current Full −100 +100 μA
Low Level Input Current Full −100 +100 μA
Input Capacitance Full 4 pF
Input Resistance Full 8 10 12 kΩ SYNC INPUT
Logic Compliance CMOS
Internal Bias Full 0.9 V
Input Voltage Range Full AGND AVDD V
High Level Input Voltage Full 1.2 AVDD V
Low Level Input Voltage Full AGND 0.6 V
High Level Input Current Full −100 +100 μA
Low Level Input Current Full −100 +100 μA
Input Capacitance Full 1 pF
Input Resistance Full 12 16 20
Rev. A | Page 7 of 44
AD9258
Parameter Temperature Min Typ Max Unit
LOGIC INPUT (CSB)1
High Level Input Voltage Full 1.22 2.1 V Low Level Input Voltage Full 0 0.6 V High Level Input Current Full −10 +10 μA Low Level Input Current Full 40 132 μA Input Resistance Full 26 kΩ Input Capacitance Full 2 pF
LOGIC INPUT (SCLK/DFS)2
High Level Input Voltage Full 1.22 2.1 V Low Level Input Voltage Full 0 0.6 V High Level Input Current (VIN = 1.8 V) Full −92 −135 μA Low Level Input Current Full −10 +10 μA Input Resistance Full 26 kΩ Input Capacitance Full 2 pF
LOGIC INPUT/OUTPUT (SDIO/DCS)
High Level Input Voltage Full 1.22 2.1 V Low Level Input Voltage Full 0 0.6 V High Level Input Current Full −10 +10 μA Low Level Input Current Full 38 128 μA Input Resistance Full 26 kΩ Input Capacitance Full 5 pF
LOGIC INPUTS (OEB, PDWN)
High Level Input Voltage Full 1.22 2.1 V Low Level Input Voltage Full 0 0.6 V High Level Input Current (VIN = 1.8 V) Full −90 −134 μA Low Level Input Current Full −10 +10 μA Input Resistance Full 26 kΩ Input Capacitance Full 5 pF
DIGITAL OUTPUTS
CMOS Mode—DRVDD = 1.8 V
High Level Output Voltage
IOH = 50 μA Full 1.79 V IOH = 0.5 mA Full 1.75 V
Low Level Output Voltage
IOL = 1.6 mA Full 0.2 V IOL = 50 μA Full 0.05 V
LVDS Mode—DRVDD = 1.8 V
Differential Output Voltage (VOD), ANSI Mode Full 290 345 400 mV Output Offset Voltage (VOS), ANSI Mode Full 1.15 1.25 1.35 V Differential Output Voltage (VOD), Reduced Swing Mode Full 160 200 230 mV Output Offset Voltage (VOS), Reduced Swing Mode Full 1.15 1.25 1.35 V
1
Pull up.
2
Pull down.
1
2
Rev. A | Page 8 of 44
AD9258

SWITCHING SPECIFICATIONS

AVDD = 1.8 V, DRVDD = 1.8 V, maximum sample rate, VIN = −1.0 dBFS differential input, 1.0 V internal reference, and DCS enabled, unless otherwise noted.
Table 4.
AD9258BCPZ-80 AD9258BCPZ-105 AD9258BCPZ-125 Parameter Temperature Min Typ Max Min Typ Max Min Typ Max Unit
CLOCK INPUT PARAMETERS
Input Clock Rate Full 625 625 625 MHz
Conversion Rate1
DCS Enabled Full 20 80 20 105 20 125 MSPS
DCS Disabled Full 10 80 10 105 10 125 MSPS CLK Period—Divide-by-1 Mode (t CLK Pulse Width High (tCH)
Divide-by-1 Mode, DCS Enabled Full
Divide-by-1 Mode, DCS Disabled Full
Divide-by-2 Mode Through
Divide-by-8 Mode Aperture Delay (tA) Full 1.0 1.0 1.0 ns Aperture Uncertainty (Jitter, tJ) Full 0.07 0.07 0.07
DATA OUTPUT PARAMETERS
CMOS Mode
Data Propagation Delay (tPD) Full 2.8 3.5 DCO Propagation Delay (t
DCO to Data Skew (t
SKEW
LVDS Mode
Data Propagation Delay (tPD Full 2.9 3.7 4.5 2.9 3.7 4.5 2.9 3.7 4.5 ns DCO Propagation Delay (t DCO to Data Skew (t
SKEW
CMOS Mode Pipeline Delay
(Latency)
LVDS Mode Pipeline Delay
(Latency) Channel A/Channel B Wake-Up Time3 Full 500 500 500 μs Out-of-Range Recovery Time Full 2 2 2 Cycles
1
Conversion rate is the clock rate after the divider.
2
Additional DCO delay can be added by writing to Bit 0 through Bit 4 in SPI Register 0x17 (see Table 17).
3
Wake-up time is defined as the time required to return to normal operation from power-down mode.
) Full 12.5 9.5 8 ns
CLK
3.75
6.25
5.95
6.25
Full 0.8
8.75 2.85
6.55 4.5
0.8
4.75
4.75
6.65
2.4 4 5.6 ns
5.0
3.8 4 4.2 ns
0.8
ns
ps rms
)2 Full
DCO
4.2 2.8
3.1
3.5 4.2 2.8 3.5 4.2 ns
3.1
3.1
ns
) Full −0.6 −0.4 0 −0.6 −0.4 0 −0.6 −0.4 0 ns
)2 Full
DCO
3.9
3.9
3.9
ns
) Full −0.1 +0.2 +0.5 −0.1 +0.2 +0.5 −0.1 +0.2 +0.5 ns
Full 12 12 12 Cycles
Full 12/12.5 12/12.5 12/12.5 Cycles
Rev. A | Page 9 of 44
AD9258

TIMING SPECIFICATIONS

Table 5.
Parameter Conditions Limit
SYNC TIMING REQUIREMENTS
t
SYNC to rising edge of CLK+ setup time 0.30 ns typ
SSYNC
t
SYNC to rising edge of CLK+ hold time 0.40 ns typ
HSYNC
SPI TIMING REQUIREMENTS
tDS Setup time between the data and the rising edge of SCLK 2 ns min tDH Hold time between the data and the rising edge of SCLK 2 ns min t
Period of the SCLK 40 ns min
CLK
tS Setup time between CSB and SCLK 2 ns min tH Hold time between CSB and SCLK 2 ns min t
SCLK pulse width high 10 ns min
HIGH
t
SCLK pulse width low 10 ns min
LOW
t
EN_SDIO
t
DIS_SDIO

Timing Diagrams

CH A/CH B DATA
CH A/CH B DATA
VIN
CLK+ CLK–
DCOA/DCOB
VIN
CLK+ CLK–
DCOA/DCOB
Time required for the SDIO pin to switch from an input to an output relative to the SCLK falling edge
Time required for the SDIO pin to switch from an output to an input relative to the SCLK rising edge
N – 1
t
CH
t
A
N
N + 1
t
CLK
t
DCO
t
SKEW
N – 12N – 13
t
PD
N + 2
N – 11 N – 10 N – 9 N – 8
Figure 2. CMOS Default Output Mode Data Output Timing
N – 1
t
CH
t
DCO
t
A
N
N + 1
t
CLK
t
SKEW
t
PD
CH A
CH B
N – 12
N – 12
CH A
N – 11
N + 2
CH B
N – 11
CH A
N – 10
Figure 3. CMOS Interleaved Output Mode Data Output Timing
N + 3
N + 3
CH B
N – 10
CH A N – 9
N + 4
N + 4
CH B N – 9
CH A N – 8
N + 5
N + 5
10 ns min
10 ns min
08124-002
08124-057
Rev. A | Page 10 of 44
AD9258
VIN
CLK+ CLK–
DCOA/DCOB
CH A/CH B DATA
N – 1
CH A N – 9
N + 4
CH B N – 9
CH A N – 8
N + 5
08124-003
t
A
N
N + 1
t
CH
t
DCO
t
CLK
t
t
SKEW
PD
CH A
CH B
N – 12
N – 12
CH A
N – 11
N + 2
CH B
N – 11
CH A
N – 10
N + 3
CH B
N – 10
Figure 4. LVDS Mode Data Output Timing
CLK+
SYNC
t
SSYNC
t
HSYNC
08124-004
Figure 5. SYNC Input Timing Requirements
Rev. A | Page 11 of 44
AD9258

ABSOLUTE MAXIMUM RATINGS

Table 6.
Parameter Rating
ELECTRICAL
1
AVDD to AGND −0.3 V to +2.0 V DRVDD to AGND −0.3 V to +2.0V VIN+A/VIN+B, VIN−A/VIN−B to AGND −0.3 V to AVDD + 0.2 V CLK+, CLK− to AGND −0.3 V to AVDD + 0.2 V SYNC to AGND −0.3 V to AVDD + 0.2 V VREF to AGND −0.3 V to AVDD + 0.2 V SENSE to AGND −0.3 V to AVDD + 0.2 V VCM to AGND −0.3 V to AVDD + 0.2 V RBIAS to AGND −0.3 V to AVDD + 0.2 V CSB to AGND −0.3 V to DRVDD + 0.2 V SCLK/DFS to AGND −0.3 V to DRVDD + 0.2 V SDIO/DCS to AGND −0.3 V to DRVDD + 0.2 V OEB −0.3 V to DRVDD + 0.2 V PDWN −0.3 V to DRVDD + 0.2 V D0A/D0B through D13A/D13B to
AGND
DCOA/DCOB to AGND
−0.3 V to DRVDD + 0.2 V
−0.3 V to DRVDD + 0.2 V
ENVIRONMENTAL
Operating Temperature Range
−40°C to +85°C
(Ambient)
Maximum Junction Temperature
150°C
Under Bias
Storage Temperature Range
−65°C to +150°C
(Ambient)
1
The inputs and outputs are rated to the supply voltage (AVDD or DRVDD) +
0.2 V but should not exceed 2.1 V.
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 CHARACTERISTICS

The exposed paddle must be soldered to the ground plane for the LFCSP package. Soldering the exposed paddle to the PCB increases the reliability of the solder joints and maximizes the thermal capability of the package.
Typical θ
is specified for a 4-layer PCB with a solid ground
JA
plane. As shown in Table 7, airflow improves heat dissipation, which reduces θ
. In addition, metal in direct contact with the
JA
package leads from metal traces, through holes, ground, and power planes, reduces θ
.
JA
Table 7. Thermal Resistance
Airflow
Packa ge Type
64-Lead LFCSP (CP-64-6)
Veloc ity (m/sec) θ
0 18.5 1.0 °C/W
1.0 16.1 9.2 °C/W
1, 2
JA
1, 3
θ
JC
1, 4
θ
Unit
JB
2.5 14.5 °C/W
1
Per JEDEC 51-7, plus JEDEC 25-5 2S2P test board. 2 Per JEDEC JESD51-2 (still air) or JEDEC JESD51-6 (moving air). 3 Per MIL-Std 883, Method 1012.1. 4 Per JEDEC JESD51-8 (still air).

ESD CAUTION

Rev. A | Page 12 of 44
AD9258

PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS

AVDD
AVDD
VIN+B
VIN–B
AVDD
AVDD
RBIAS
VCM
SENSE
VREF
AVDD
AVDD
VIN–A
VIN+A
AVDD
646362616059585756555453525150
AVDD 49
CLK+ CLK–
SYNC
NC NC
D0B (LSB)
D1B D2B D3B
DRVDD
10
D4B
11
D5B
12
D6B
13
D7B
14
D8B
15
D9B
16
NOTES
1. NC = NO CONNECT.
2. THE EXPOSED THERMAL PAD ON THE BOTTOM OF THE PACKAGE PROVIDES THE ANALOG G ROUND FOR THE P ART. THIS EXPOSED PAD MUST BE CONNECTED TO GROUND FOR PROPE R OPERATIO N.
PIN 1
1
INDICATOR
2 3 4 5 6 7 8 9
171819202122232425262728293031
D10B
PARALLEL CMOS
(Not to Scale)
D11B
D12B
DRVDD
D13B (MSB)
AD9258
TOP VIEW
NC
ORB
DCOA
DCOB
NC
D1A
D2A
DRVDD
D0A (LSB)
48
PDWN
47
OEB
46
CSB
45
SCLK/DFS
44
SDIO/DCS
43
ORA
42
D13A (MSB)
41
D12A
40
D11A
39
D10A
38
D9A
37
DRVDD
36
D8A
35
D7A
34
D6A
33
D5A
32
D3A
D4A
08124-005
Figure 6. LFCSP Parallel CMOS Pin Configuration (Top View)
Table 8. Pin Function Descriptions (Parallel CMOS Mode)
Pin No. Mnemonic Type Description
ADC Power Supplies 10, 19, 28, 37 DRVDD Supply Digital Output Driver Supply (1.8 V Nominal). 49, 50, 53, 54, 59,
AVDD Supply Analog Power Supply (1.8 V Nominal).
60, 63, 64 4, 5, 25, 26 NC Do Not Connect. 0
AGND, Exposed Pad
Ground
The exposed thermal pad on the bottom of the package provides the analog ground for the part. This exposed pad must be connected to ground for proper
operation. ADC Analog 51 VIN+A Input Differential Analog Input Pin (+) for Channel A. 52 VIN−A Input Differential Analog Input Pin (−) for Channel A. 62 VIN+B Input Differential Analog Input Pin (+) for Channel B. 61 VIN−B Input Differential Analog Input Pin (−) for Channel B. 55 VREF Input/Output Voltage Reference Input/Output. 56 SENSE Input Voltage Reference Mode Select. See Table 1 1 for details. 58 RBIAS Input/Output External Reference Bias Resistor. 57 VCM Output Common-Mode Level Bias Output for Analog Inputs. 1 CLK+ Input ADC Clock Input—True. 2 CLK− Input ADC Clock Input—Complement. Digital Input 3 SYNC Input Digital Synchronization Pin. Slave mode only. Digital Outputs 27 D0A (LSB) Output Channel A CMOS Output Data. 29 D1A Output Channel A CMOS Output Data. 30 D2A Output Channel A CMOS Output Data. 31 D3A Output Channel A CMOS Output Data.
Rev. A | Page 13 of 44
AD9258
Pin No. Mnemonic Type Description
32 D4A Output Channel A CMOS Output Data. 33 D5A Output Channel A CMOS Output Data. 34 D6A Output Channel A CMOS Output Data. 35 D7A Output Channel A CMOS Output Data. 36 D8A Output Channel A CMOS Output Data. 38 D9A Output Channel A CMOS Output Data. 39 D10A Output Channel A CMOS Output Data. 40 D11A Output Channel A CMOS Output Data. 41 D12A Output Channel A CMOS Output Data. 42 D13A (MSB) Output Channel A CMOS Output Data. 43 ORA Output Channel A Overrange Output. 6 D0B (LSB) Output Channel B CMOS Output Data. 7 D1B Output Channel B CMOS Output Data. 8 D2B Output Channel B CMOS Output Data. 9 D3B Output Channel B CMOS Output Data. 11 D4B Output Channel B CMOS Output Data. 12 D5B Output Channel B CMOS Output Data. 13 D6B Output Channel B CMOS Output Data. 14 D7B Output Channel B CMOS Output Data. 15 D8B Output Channel B CMOS Output Data. 16 D9B Output Channel B CMOS Output Data. 17 D10B Output Channel B CMOS Output Data. 18 D11B Output Channel B CMOS Output Data. 20 D12B Output Channel B CMOS Output Data. 21 D13B (MSB) Output Channel B CMOS Output Data. 22 ORB Output Channel B Overrange Output 24 DCOA Output Channel A Data Clock Output. 23 DCOB Output Channel B Data Clock Output. SPI Control 45 SCLK/DFS Input SPI Serial Clock/Data Format Select Pin in External Pin Mode. 44 SDIO/DCS Input/Output SPI Serial Data I/O/Duty Cycle Stabilizer Pin in External Pin Mode. 46 CSB Input SPI Chip Select (Active Low). ADC Configuration 47 OEB Input Output Enable Input (Active Low) in External Pin Mode.
48 PDWN Input
Power-Down Input in External Pin Mode. In SPI mode, this input can be configured as power-down or standby.
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