ANALOG DEVICES ADF4360-0 Service Manual

Integrated Synthesizer and VCO
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FEATURES

Output frequency range: 2400 MHz to 2725 MHz Divide-by-2 output
3.0 V to 3.6 V power supply
1.8 V logic compatibility Integer-N synthesizer Programmable dual-modulus prescaler 16/17, 32/33 Programmable output power level 3-wire serial interface Analog and digital lock detect Hardware and software power-down mode

APPLICATIONS

Wireless handsets (DECT, GSM, PCS, DCS, WCDMA) Test equipment Wireless LANs CATV equipment

FUNCTIONAL BLOCK DIAGRAM

ADF4360-0
REF
CLK
DATA
IN
LE
14-BIT R
COUNTER
24-BIT
DATA REGISTER
AV
DD
24-BIT
FUNCTION
LATCH
DV
ADF4360-0

GENERAL DESCRIPTION

The ADF4360-0 is a fully integrated integer-N synthesizer and voltage-controlled oscillator (VCO). The ADF4360-0 is de­signed for a center frequency of 2600 MHz. In addition, a di­vide-by-2 option is available, whereby the user gets an RF out­put of between 1200 MHz and 1360 MHz.
Control of all the on-chip registers is through a simple 3-wire interface. The device operates with a power supply ranging from
3.0 V to 3.6 V and can be powered down when not in use.
CE
PHASE
R
SET
MULTIPLEXER
CHARGE
PUMP
MUTE
MUXOUT
CP
V
VCO
V
TUNE
C
C
C
N
DD
LOCK
DETECT
COMPARATOR
INTEGER
REGISTER
13-BIT B
COUNTER
PRESCALER
P/P+1
N = (BP + A)
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.
LOAD LOAD
5-BIT A
COUNTER
AGND DGND CPGND
MULTIPLEXER
Figure 1.
RF
A
OUT
RF
OUT
04644-001
B
DIVSEL = 1
DIVSEL = 2
VCO
CORE
OUTPUT
STAGE
÷2
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.326.8703 © 2004 Analog Devices, Inc. All rights reserved.
ADF4360-0
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TABLE OF CONTENTS

Specifications..................................................................................... 3
VCO ............................................................................................. 10
Timing Characteristics..................................................................... 5
Absolute Maximum Ratings............................................................ 6
Transi s t o r Cou nt ........................................................................... 6
ESD Caution.................................................................................. 6
Pin Configuration and Function Descriptions............................. 7
Typical Performance Characteristics............................................. 8
Circuit Description........................................................................... 9
Reference Input Section............................................................... 9
Prescaler (P/P + 1)........................................................................ 9
A and B Counters ......................................................................... 9
R Counter ...................................................................................... 9
PFD and Charge Pump................................................................ 9
MUXOUT and Lock Detect...................................................... 10
Input Shift Register..................................................................... 10
Output Stage................................................................................ 11
Latch Structure ........................................................................... 12
Power-Up..................................................................................... 16
Control Latch.............................................................................. 18
N Counter Latch......................................................................... 19
R Counter Latch ......................................................................... 19
Applications..................................................................................... 20
Fixed Frequency LO................................................................... 20
Interfacing ................................................................................... 20
PCB Design Guidelines for Chip Scale Package........................... 21
Output Matching........................................................................ 21
Outline Dimensions....................................................................... 22
Ordering Guide .......................................................................... 22
REVISION HISTORY
12/04—Rev. 0 to Rev. A
Updated Format..................................................................Universal
Changes to Timing Characteristics................................................ 5
Changes to Power-Up Section ...................................................... 16
Added Table 10 ............................................................................... 16
Added Figure 16.............................................................................. 16
Changes to Ordering Guide.......................................................... 22
Updated Outline Dimensions....................................................... 22
7/04—Revision 0: Initial Version
Rev. A | Page 2 of 24
ADF4360-0
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SPECIFICATIONS

AVDD = DVDD = V
Table 1.
Parameter B Version Unit Conditions/Comments
REFIN CHARACTERISTICS
REFIN Input Frequency 10/250 MHz min/max
REFIN Input Sensitivity 0.7/AV 0 to AVDD V max CMOS-compatible. REFIN Input Capacitance 5.0 pF max REFIN Input Current ±100 µA max
PHASE DETECTOR
Phase Detector Frequency2 8 MHz max
CHARGE PUMP
ICP Sink/Source3 With R
High Value 2.5 mA typ Low Value 0.312 mA typ R
Range 2.7/10 kΩ
SET
ICP Three-State Leakage Current 0.2 nA typ Sink and Source Current Matching 2 % typ 1.25 V ≤ VCP ≤ 2.5 V. ICP vs. VCP 1.5 % typ 1.25 V ≤ VCP ≤ 2.5 V. ICP vs. Temperature 2 % typ VCP = 2.0 V.
LOGIC INPUTS
V
, Input High Voltage 1.5 V min
INH
V
, Input Low Voltage 0.6 V max
INL
I
, Input Current ±1 µA max
INH/IINL
CIN, Input Capacitance 3.0 pF max
LOGIC OUTPUTS
VOH, Output High Voltage DVDD – 0.4 V min CMOS output chosen. IOH, Output High Current 500 µA max VOL, Output Low Voltage 0.4 V max IOL = 500 µA.
POWER SUPPLIES
AVDD 3.0/3.6 V min/V max DVDD AV V
AV
VCO
4
AI
DD
4
DI
DD
4, 5
I
VCO
4
I
RFOUT
Low Power Sleep Mode4 7 µA typ
RF OUTPUT CHARACTERISTICS5
VCO Output Frequency 2400/2725 MHz min/max I VCO Sensitivity 56 MHz/V typ Lock Time Frequency Pushing (Open-Loop) 1 MHz/V typ Frequency Pulling (Open-Loop) 15 kHz typ Into 2.00 VSWR load. Harmonic Content (Second) −30 dBc typ Harmonic Content (Third) −39 dBc typ Output Power Output Power Variation ±3 dB typ For tuned loads, see the Output Matching section. VCO Tuning Range 1.25/2.50 V min/max VCO Tuning Port Leakage Current 0.2 nA typ
VCO
6
5, 7
1
= 3.3 V ± 10%; AGND = DGND = 0 V; TA = T
DD
DD
DD
10 mA typ
2.5 mA typ
19.0 mA typ I
3.5 to 11.0 mA typ RF output stage is programmable.
250 µs typ To within 10 Hz of final frequency.
−13/−6.5 dBm typ Programmable in 3 dB steps. See Table 7.
MIN
to T
, unless otherwise noted.
MAX
For f < 10 MHz, use dc-coupled CMOS-compati
ble square wave, slew rate > 21 V/µs.
V p-p min/max AC-coupled.
= 4.7 kΩ.
SET
= 10 mA.
CORE
= 15 mA.
CORE
Rev. A | Page 3 of 24
ADF4360-0
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Parameter B Version Unit Conditions/Comments
NOISE CHARACTERISTICS5
VCO Phase-Noise Performance
−133 dBc/Hz typ @ 1 MHz offset from carrier.
−140 dBc/Hz typ @ 3 MHz offset from carrier.
−145 dBc/Hz typ @ 10 MHz offset from carrier.
Synthesizer Phase-Noise Floor
−163 dBc/Hz typ @ 200 kHz PFD frequency.
−147 dBc/Hz typ @ 8 MHz PFD frequency.
In-Band Phase Noise
10, 11
RMS Integrated Phase Error12 1.4 Degrees typ 100 Hz to 100 kHz.
Spurious Signals due to PFD Frequency
Level of Unlocked Signal with MTLD Enabled −45 dBm typ
1
Operating temperature range is: –40°C to +85°C.
2
Guaranteed by design. Sample tested to ensure compliance.
3
ICP is internally modified to maintain constant loop gain over the frequency range.
4
TA = 25°C; AVDD = DVDD = V
5
These characteristics are guaranteed for VCO core power = 10 mA.
6
Jumping from 2.4 GHz to 2.725 GHz. PFD frequency = 200 kHz; loop bandwidth = 10 kHz.
7
Using 50 Ω resistors to V
8
The noise of the VCO is measured in open-loop conditions.
9
The synthesizer phase-noise floor is estimated by measuring the in-band phase noise at the output of the VCO and subtracting 20 log N (where N is the N divider value).
10
The phase noise is measured with the EVAL-ADF4360-xEB1 Evaluation Board and the HP8562E Spectrum Analyzer. The spectrum analyzer provides the REFIN for the
synthesizer; offset frequency = 1 kHz.
11
f
= 10 MHz; f
REFIN 12
f
= 10 MHz; f
REFIN 13
The spurious signals are measured with the EVAL-ADF4360-xEB1 Evaluation Board and the HP8562E Spectrum Analyzer. The spectrum analyzer provides the REFIN for
the synthesizer; f
VCO
into a 50 Ω load. For tuned loads, see the Output Matching section.
VCO
= 200 kHz; N = 2600; Loop B/W = 10 kHz.
PFD
= 1 MHz; N = 2600; Loop B/W = 25 kHz.
PFD
= 10 MHz @ 0 dBm.
REFOUT
8
9
= 3.3 V; P = 32.
11, 13
−111 dBc/Hz typ @ 100 kHz offset from carrier.
−172 dBc/Hz typ @ 25 kHz PFD frequency.
−80 dBc/Hz typ @ 1 kHz offset from carrier.
−75 dBc typ
Rev. A | Page 4 of 24
ADF4360-0
K
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TIMING CHARACTERISTICS

AVDD = DVDD = V
Table 2.
Parameter Limit at T
t1 20 ns min LE Setup Time t2 10 ns min DATA to CLOCK Setup Time t3 10 ns min DATA to CLOCK Hold Time t4 25 ns min CLOCK High Duration t5 25 ns min CLOCK Low Duration t6 10 ns min CLOCK to LE Setup Time t7 20 ns min LE Pulse Width
1
See the section for the recommended power-up procedure for this device. Power-Up
= 3.3 V ± 10%; AGND = DGND = 0 V; 1.8 V and 3 V logic levels used; TA = T
VCO
MIN
1
to T
MIN
to T
(B Version) Unit Test Conditions/Comments
MAX
, unless other wise noted.
MAX
CLOC
DATA
t
2
DB23 (MSB) DB22 DB2
LE
t
1
LE
t
3
t
4
Figure 2. Timing Diagram
t
5
DB1
(CONTROL BIT C2)
DB0 (LSB)
(CONTROL BIT C1)
t
6
t
7
04644-002
Rev. A | Page 5 of 24
ADF4360-0
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ABSOLUTE MAXIMUM RATINGS

TA = 25°C, unless otherwise noted.
Table 3.
Parameter Rating
AVDD to GND AVDD to DVDD −0.3 V to +0.3 V V
to GND −0.3 V to +3.9 V
VCO
V
to AVDD −0.3 V to +0.3 V
VCO
Digital I/O Voltage to GND −0.3 V to VDD + 0.3 V Analog I/O Voltage to GND −0.3 V to VDD + 0.3 V REFIN to GND −0.3 V to VDD + 0.3 V Operating Temperature Range −40°C to + 85°C Storage Temperature Range −65°C to +150°C Maximum Junction Temperature 150°C CSP θJA Thermal Impedance
Paddle Soldered 50°C/W
Paddle Not Soldered 88°C/W Lead Temperature, Soldering
Vapor Phase (60 sec) 215°C
Infrared (15 sec) 220°C
1
GND = AGND = DGND = 0 V.
1
−0.3 V to +3.9 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 included in the operational sec­tions of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
This device is a high performance RF integrated circuit with an ESD rating of <1 kV and it is ESD sensitive. Proper precautions should be taken for handling and assembly.

TRANSISTOR COUNT

12543 (CMOS) and 700 (Bipolar).

ESD CAUTION

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although this product features proprie­tary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality.
Rev. A | Page 6 of 24
ADF4360-0
T
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PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

DD
21
PIN 1 IDENTIFIER
ADF4360-0
TOP VIEW
(Not to Scale)
AGND8AGND9AGND10AGND
MUXOU
20LE19
11
18
DATA CLK
17
REF
16
IN
DGND
15
C
14
N
R
13
SET
12
C
C
04644-003
CPGND
AV
AGND
RF
OUT
RF
OUT
V
VCO
CP24CE23AGND22DV
1 2
DD
3
A
4
B
5 6
7
TUNE
V
Figure 3. Pin Configuration
Table 4. Pin Function Descriptions
Pin No. Mnemonic Function
1 CPGND Charge Pump Ground. This is the ground return path for the charge pump. 2 AVDD
Analog Power Supply. This ranges from 3.0 V to 3.6 V. Decoupling capacitors to the analog ground plane should be placed as close as possible to this pin. AV
must have the same value as DVDD.
DD
3, 8 to 11, 22 AGND Analog Ground. This is the ground return path of the prescaler and VCO. 4 RF
OUT
A
VCO Output. The output level is programmable from −6.5 dBm to −13 dBm. See the Output Matching section for a description of the various output stages.
5 RF
OUT
B
VCO Complementary Output. The output level is programmable from −6.5 dBm to −13 dBm. See the Output Matching section for a description of the various output stages.
6 V
7 V
VCO
TUNE
Power Supply for the VCO. This ranges from 3.0 V to 3.6 V. Decoupling capacitors to the analog ground plane should be placed as close as possible to this pin. V
must have the same value as AVDD.
VCO
Control Input to the VCO. This voltage determines the output frequency and is derived from filtering the CP
output voltage. 12 CC Internal Compensation Node. This pin must be decoupled to ground with a 10 nF capacitor. 13 R
14 C
SET
N
Connecting a resistor between this pin and CP
thesizer. The nominal voltage potential at the R
75.11
I
where R
CPmax
= 4.7 kΩ, I
SET
=
R
SET
= 2.5 mA.
CPmax
Internal Compensation Node. This pin must be decoupled to V
sets the maximum charge pump output current for the syn-
GND
pin is 0.6 V. The relationship between ICP and R
SET
with a 10 µF capacitor.
VCO
15 DGND Digital Ground. 16 REFIN
Reference Input. This is a CMOS input with a nominal threshold of V
/2 and a dc equivalent input resistance of
DD
100 kΩ. See Figure 10. This input can be driven from a TTL or CMOS crystal oscillator or it can be ac-coupled. 17 CLK
Serial Clock Input. This serial clock is used to clock in the serial data to the registers. The data is latched into the
24-bit shift register on the CLK rising edge. This input is a high impedance CMOS input. 18 DATA
Serial Data Input. The serial data is loaded MSB first with the two LSBs being the control bits. This input is a
high impedance CMOS input. 19 LE
Load Enable, CMOS Input. When LE goes high, the data stored in the shift registers is loaded into one of the
four latches, and the relevant latch is selected using the control bits. 20 MUXOUT
This multiplexer output allows either the lock detect, the scaled RF, or the scaled reference frequency to be
accessed externally. 21 DVDD
23 CE
Digital Power Supply. This ranges from 3.0 V to 3.6 V. Decoupling capacitors to the digital ground plane should
be placed as close as possible to this pin. DV
must have the same value as AVDD.
DD
Chip Enable. A logic low on this pin powers down the device and puts the charge pump into three-state mode.
Taking the pin high powers up the device depending on the status of the power-down bits. 24 CP
Charge Pump Output. When enabled, this provides ± I
internal VCO.
to the external loop filter, which in turn, drives the
CP
SET
is
Rev. A | Page 7 of 24
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TYPICAL PERFORMANCE CHARACTERISTICS

0 –10 –20 –30 –40 –50 –60 –70 –80 –90
–100 –110 –120
OUTPUT POWER (dB)
–130 –140 –150 –160 –170
1k 10M1M100k10k
1
2
FREQUENCY OFFSET (Hz)
Figure 4. Open-Loop VCO Phase Noise
3
4
04644-004
0
–10
–20
–30
–40
–50
–60
–70
OUTPUT POWER (dB)
–80 –90
–2kHz –1kHz 2600MHz 1kHz 2kHz
REFERENCE
LEVEL = –3.5dBm
VDD = 3.3V, V
= 2.5mA
I
CP
PFD FREQUENCY = 200kHz LOOP BANDWIDTH = 10kHz RES. BANDWIDTH = 30Hz VIDEO BANDWIDTH = 30Hz SWEEP = 1.9 SECONDS AVERAGES = 20
= 3.3V
VCO
–80.4dBc/Hz
04644-007
Figure 7. Close-In Phase Noise at 2600 MHz (200 kHz Channel Spacing)
–70 –75 –80 –85 –90 –95
–100 –105 –110 –115 –120 –125
OUTPUT POWER (dB)
–130 –135 –140 –145 –150
100 10M1M100k10k1000
FREQUENCY OFFSET (Hz)
04644-005
Figure 5. VCO Phase Noise, 2600 MHz, 200 kHz PFD, 10 kHz Loop Bandwidth
–70 –75 –80 –85 –90 –95
–100 –105 –110 –115 –120 –125
OUTPUT POWER (dB)
–130 –135 –140 –145 –150
100 10M1M100k10k1000
FREQUENCY OFFSET (Hz)
04644-006
Figure 6. VCO Phase Noise, 1300 MHz,
Divide-by-2 Enabled, 200 kHz PFD, 10 kHz Loop Bandwidth
0
–10
–20
–30
–40
–50
–60
–70
OUTPUT POWER (dB)
–80 –90
–0.25MHz –0.1MHz 2600MHz 0.1MHz 0.25MHz
REFERENCE
LEVEL = –6dBm
VDD = 3.3V, V I
= 2.5mA
CP
PFD FREQUENCY = 200kHz LOOP BANDWIDTH = 10kHz RES. BANDWIDTH = 1kHz VIDEO BANDWIDTH = 1kHz AVERAGES = 20
VCO
–77dBc
= 3.3V
Figure 8. Reference Spurs at 2600 MHz
(200 kHz Channel Spacing, 10 kHz Loop Bandwidth)
0
VDD = 3V, V
–10
I
= 2.5mA
CP
PFD FREQUENCY = 1MHz
–20
LOOP BANDWIDTH = 25kHz RES. BANDWIDTH = 10kHz
–30
VIDEO BANDWIDTH = 10kHz SWEEP = 1.9 SECONDS AVERAGES = 10
–40
–50
–60
–70
OUTPUT POWER (dB)
–80 –90
–1MHz –0.5MHz 2250MHz 0.5MHz 1MHz
VCO
= 3V
–86dBc/Hz
Figure 9. Reference Spurs at 2600 MHz
(1 MHz Channel Spacing, 25 kHz Loop Bandwidth)
04644-008
04644-009
Rev. A | Page 8 of 24
ADF4360-0
C
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CIRCUIT DESCRIPTION

REFERENCE INPUT SECTION

The reference input stage is shown in Figure 10. SW1 and SW2 are normally closed switches. SW3 is normally open. When power-down is initiated, SW3 is closed, and SW1 and SW2 are opened. This ensures that there is no loading of the REF
IN
pin
on power-down.
POWER-DOWN
CONTROL
100k
NC
SW1
SW2
SW3
NO
REF
IN
NC
Figure 10. Reference Input Stage
BUFFER
TO R COUNTER
04644-010

PRESCALER (P/P + 1)

The dual-modulus prescaler (P/P + 1), along with the A and B counters, enables the large division ratio,
N, to be realized
(N = BP + A). The dual-modulus prescaler, operating at CML levels, takes the clock from the VCO and divides it down to a manageable frequency for the CMOS A and B counters. The prescaler is programmable. It can be set in software to 8/9, 16/17, or 32/33 and is based on a synchronous 4/5 core. There is a minimum divide ratio possible for fully contiguous output frequencies; this minimum is determined by P, the prescaler
2
value, and is given by (P
− P).

A AND B COUNTERS

The A and B CMOS counters combine with the dual-modulus prescaler to allow a wide range division ratio in the PLL feed­back counter. The counters are specified to work when the pre­scaler output is 300 MHz or less. Thus, with a VCO frequency of
2.5 GHz, a prescaler value of 16/17 is valid, but a value of 8/9 is not valid.

Pulse Swallow Function

The A and B counters, in conjunction with the dual-modulus prescaler, make it possible to generate output frequencies that are spaced only by the reference frequency divided by R. The VCO frequency equation is
RfABPf
REFIN
/×]+×[=
where:
VCO
()
FROM VCO

R COUNTER

The 14-bit R counter allows the input reference frequency to be divided down to produce the reference clock to the phase frequency detector (PFD). Division ratios from 1 to 16,383 are allowed.

PFD AND CHARGE PUMP

The PFD takes inputs from the R counter and N counter (N = BP + A) and produces an output proportional to the phase and frequency difference between them. Figure 12 is a simpli­fied schematic. The PFD includes a programmable delay ele­ment that controls the width of the antibacklash pulse. This pulse ensures that there is no dead zone in the PFD transfer function and minimizes phase noise and reference spurs. Two bits in the R counter latch, ABP2 and ABP1, control the width of the pulse (see Table 9).
HI
R DIVIDER
HI
N DIVIDER
N = BP + A
PRESCALER
P/P+1
MODULUS CONTROL
N DIVIDER
Figure 11. A and B Counters
UP
Q1D1
U1
CLR1
PROGRAMMABLE
DELAY
ABP1 ABP2
CLR2
DOWN
Q2D2
U2
13-BIT B
COUNTER
LOAD
LOAD
5-BIT A
COUNTER
U3
04644-011
V
P
CPGND
TO PFD
CHARGE
PUMP
CP
f
is the output frequency of the VCO.
VCO
P is the preset modulus of the dual-modulus prescaler (8/9,
16/17, and so on).
B is the preset divide ratio of the binary 13-bit counter (3 to 8191). A is the preset divide ratio of the binary 5-bit swallow counter (0 to 31). f
is the external reference frequency oscillator.
REFIN
Rev. A | Page 9 of 24
R DIVIDER
N DIVIDER
P OUTPUT
Figure 12. PFD Simplified Schematic and Timing (In Lock)
04644-012
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MUXOUT AND LOCK DETECT

The output multiplexer on the ADF4360 family allows the user to access various internal points on the chip. The state of MUXOUT is controlled by M3, M2, and M1 in the function latch. The full truth table is shown in Table 7. Figure 13 shows the MUXOUT section in block diagram form.

Lock Detect

MUXOUT can be programmed for two types of lock detect: digital and analog. Digital lock detect is active high. When LDP in the R counter latch is set to 0, digital lock detect is set high when the phase error on three consecutive phase detector cycles is less than 15 ns.
Table 5. C2 and C1 Truth Table
Control Bits
C2 C1
Data Latch
0 0 Control Latch 0 1 R Counter 1 0 N Counter (A and B) 1 1 Test Mode Latch
VCO
The VCO core in the ADF4360 family uses eight overlapping bands, as shown in Figure 14, to allow a wide frequency range to be covered without a large VCO sensitivity (K poor phase noise and spurious performance.
) and resultant
V
With LDP set to 1, five consecutive cycles of less than 15 ns phase error are required to set the lock detect. It stays set high until a phase error of greater than 25 ns is detected on any sub­sequent PD cycle.
The N-channel open-drain analog lock detect should be oper­ated with an external pull-up resistor of 10 kΩ nominal. When a lock has been detected, this output is high with narrow low­going pulses.
DV
DD
ANALOG LOCK DETECT
DIGITAL LOCK DETECT
R COUNTER OUTPUT N COUNTER OUTPUT
SDOUT
CONTROLMUX
Figure 13. MUXOUT Circuit
MUXOUT
DGND

INPUT SHIFT REGISTER

The ADF4360 family’s digital section includes a 24-bit input shift register, a 14-bit R counter, and an 18-bit N counter, comprised of a 5-bit A counter and a 13-bit B counter. Data is clocked into the 24-bit shift register on each rising edge of CLK. The data is clocked in MSB first. Data is transferred from the shift register to one of four latches on the rising edge of LE. The destination latch is determined by the state of the two control bits (C2, C1) in the shift register. These are the two LSBs, DB1 and DB0, as shown in Figure 2.
The truth table for these bits is shown in Table 5. Table 6 shows a summary of how the latches are programmed. Note that the test mode latch is used for factory testing and should not be programmed by the user.
04644-013
The correct band is chosen automatically by the band select logic at power-up or whenever the N counter latch is updated. It is important that the correct write sequence be followed at power-up. This sequence is
R counter latch
1.
Control latch
2.
N counter latch
3.
During band s elec t, which takes five PFD cycles, the VCO V
TUNE
is disconnected from the output of the loop filter and connected to an internal reference voltage.
2.5
2.3
2.1
1.9
1.7
1.5
1.3
VOLTAGE (V)
1.1
0.9
0.7
0.5 2200 2400 2600 2800 3000
Figure 14. Frequency vs. V
FREQUENCY (MHz)
, ADF4360-0
TUNE
04644-014
The R counter output is used as the clock for the band select logic and should not exceed 1 MHz. A programmable divider is provided at the R counter input to allow division by 1, 2, 4, or 8 and is con­trolled by Bits BSC1 and BSC2 in the R counter latch. Where the required PFD frequency exceeds 1 MHz, the divide ratio should be set to allow enough time for correct band selection.
After band select, normal PLL action resumes. The nominal value of K
is 56 MHz/V or 28 MHz/V, if divide-by-2 operation
V
has been selected (by programming DIV2 [DB22] high in the N counter latch). The ADF4360 family contains linearization cir­cuitry to minimize any variation of the product of I
and KV.
CP
Rev. A | Page 10 of 24
ADF4360-0
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The operating current in the VCO core is programmable in four steps: 5 mA, 10 mA, 15 mA, and 20 mA. This is controlled by Bits PC1 and PC2 in the control latch.

OUTPUT STAGE

The RF nected to the collectors of an NPN differential pair driven by buffered outputs of the VCO, as shown in Figure 15. To allow the user to optimize the power dissipation vs. the output power requirements, the tail current of the differential pair is pro­grammable via Bits PL1 and PL2 in the control latch. Four current levels may be set: +3.5 mA, +5 mA, +7.5 mA, and +11 mA. These levels give output power levels of −13 dBm,
−11 dBm, −8.5 dBm, and −6.5 dBm, respectively, using a 50 Ω resistor to V both outputs can be combined in a 1 + 1:1 transformer or a 180° microstrip coupler (see the Output Matching section).
A and RF
OUT
and ac coupling into a 50 Ω load. Alternatively,
DD
B pins of the ADF4360 family are con-
OUT
If the outputs are used individually, the optimum output stage consists of a shunt inductor to V
DD
.
Another feature of the ADF4360 family is that the supply current to the RF output stage is shut down until the part achieves lock as measured by the digital lock detect circuitry. This is enabled by the mute-till-lock detect (MTLD) bit in the control latch.
VCO
BUFFER/
DIVIDE BY 2
Figure 15. Output Stage ADF4360-0
RF
OUT
ARF
OUT
B
04644-015
Rev. A | Page 11 of 24
ADF4360-0
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LATCH STRUCTURE

Table 6 shows the three on-chip latches for the ADF4360 family. The two LSBs determine which latch is programmed.
Table 6. Latch Structure
CONTROL LATCH
PRESCALER
VALUE
2 SELECT
DIVIDE-BY-
RESERVED
POWER-
DB21DB22DB23
PD2P1P2
BY-2
DIVIDE-
DB21DB22DB23
CPGDIV2DIVSEL
BAND
SELECT
CLOCK
RESERVED
DB21DB22DB23 BSC2RSVRSV
CURRENT
DOWN 1
POWER-
SETTING2
DOWN 2
DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
CURRENT
SETTING1
OUTPUT
POWER
LEVEL
LD
CP GAIN
MUTE-TILL-
CP
STATE
THREE-
PHASE
DETECTOR
POLARITY
MUXOUT
CONTROL
CORE
POWER
LEVEL
RESET
COUNTER
PC1PC2CRM1M2PDPCPCPGMTLDPL1PL2CPI1CPI2CPI3CPI4CPI5CPI6PD1 M3
CONTROL
C2 (0) C1 (0)
N COUNTER LATCH
A1A2A3A4A5B1B2B3B4B5B6B7B8B9B10B11B12B13 RSV
CONTROL
C2 (1) C1 (0)
13-BIT B COUNTER
CP GAIN
DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
RESERVED
5-BIT A COUNTER
R COUNTER LATCH
ANTI-
BACKLASH
BIT
TEST
MODE
DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
LOCK
DETECT
PULSE
WIDTH
PRECISION
14-BIT REFERENCE COUNTER
R1R2R3R4R5R7R8R9R10R11R12R13R14ABP1ABP2LDPTMBBSC1 R6
CONTROL
C2 (0) C1 (1)
BITS
BITS
BITS
04644-016
Rev. A | Page 12 of 24
ADF4360-0
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Table 7. Control Latch
PRESCALER
VALUE
CURRENT
SETTING 2
DOWN 2
DOWN 1
POWER-
POWER-
DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
DB21DB22DB23
CURRENT
SETTING 1
OUTPUT
POWER
LEVEL
MUTE-TILL-
LD
CP
CP GAIN
STATE
THREE-
PHASE
MUXOUT
CONTROL
POLARITY
DETECTOR
PD2P1P2
I
CPI6 CPI5 CPI4 CPI3 CPI2 CPI1 4.7k 0
0 0 0 1 1 1 1
0 0 1 1 0 0 1 1
0 1 0 1 0 1 0 1
PL2 PL1 OUTPUT POWER LEVEL
0
0
0
1
1
0
1
1
CP
0.31
0.62
0.93
1.25
1.56
1.87
2.18
2.50
CURRENT POWER INTO 50(USING 50 TO V
3.5mA
5.0mA
7.5mA
11.0mA
(mA)
–13dBm –11dBm8dBm6dBm
CPG 0 1
MUTE-TILL-LOCK DETECT
MTLD 0
DISABLED ENABLED
1
CP
0 1
CP GAIN CURRENT SETTING 1 CURRENT SETTING 2
PHASE DETECTOR
PDP
POLARITY
0
NEGATIVE POSITIVE
1
CHARGE PUMP OUTPUT NORMAL THREE-STATE
)
VCC
CR 0
1
M3 M2 M1
001
010 011
100 101
110 111
CORE
POWER
LEVEL
RESET
COUNTER
PC2
PC1
0
0
0
1 10 11
COUNTER OPERATION
NORMAL R, A, B COUNTERS HELD IN RESET
OUTPUT THREE-STATE OUTPUT000 DIGITAL LOCK DETECT (ACTIVE HIGH) N DIVIDER OUTPUT DV
DD
R DIVIDER OUTPUT N-CHANNEL OPEN-DRAIN LOCK DETECT SERIAL DATA OUTPUT DGND
PC1PC2CRM1M2PDPCPCPGMTLDPL1PL2CPI1CPI2CPI3CPI4CPI5CPI6PD1 M3
CONTROL
BITS
C2 (0) C1 (0)
CORE POWER LEVEL 5mA 10mA 15mA 20mA
CE PIN PD2 PD1 MODE 0 X X ASYNCHRONOUS POWER-DOWN 1 X 0 NORMAL OPERATION 1 0 1 ASYNCHRONOUS POWER-DOWN 1 1 1 SYNCHRONOUS POWER-DOWN
P2 P1 PRESCALER VALUE 0 0 8/9 0 1 16/17 1 0 32/33 1 1 32/33
04644-017
Rev. A | Page 13 of 24
ADF4360-0
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Table 8. N Counter Latch
2 SELECT
DIVIDE-BY-
DIVSEL
BY-2
DIVIDE-
DB21DB22DB23
CPGDIV2
CONTROL
CP GAIN
13-BIT B COUNTER
5-BIT A COUNTER
RESERVED
DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
C2 (1) C1 (0)
A1A2A3A4A5B1B2B3B4B5B6B7B8B9B10B11B12B13 RSV
THIS BIT IS NOT USED BY THE DEVICE AND IS A DON'T CARE BIT.
A5 A4 .......... A2 A1
0 0 .......... 0 0 0
0 0 .......... 0 1 1
0 0 .......... 1 0 2
0 0 .......... 1 1 3
. . .......... . . .
. . .......... . . .
. . .......... . . .
1 1 .......... 0 0 28
1 1 .......... 0 1 29
1 1 .......... 1 0 30
1 1 .......... 1 1 31
B13 B12 B11 B3 B2 B1 B COUNTER DIVIDE RATIO
000 000 000
.. . .. .
111 111 111
.......... 0000
.......... 0 0 1 NOT ALLOWED
.......... 0 1 0 NOT ALLOWED
.......... 1 1 1 3
.......... ... .
.......... . . . .
.......... . . . .
.......... 1111
.......... 1 0 1 8189
.......... 1 1 0 8190
.......... 1 1 1 8191
0 0 NOT ALLOWED
.. .
0 0 8188
A COUNTER DIVIDE RATIO
BITS
DIVSEL 0 1
F4 (FUNCTION LATCH) FASTLOCK ENABLE
DIVIDE-BY-2
DIV2 0
FUNDAMENTAL OUTPUT DIVIDE-BY-2
1
DIVIDE-BY-2 SELECT (PRESCALER INPUT) FUNDAMENTAL OUTPUT SELECTED
DIVIDE-BY-2 SELECTED
CP GAIN OPERATION 00
10
CHARGE PUMP CURRENT SETTING 1 IS PERMANENTLY USED
CHARGE PUMP CURRENT SETTING 2 IS PERMANENTLY USED
Rev. A | Page 14 of 24
N = BP + A; P IS PRESCALER VALUE SET IN THE CONTROL LATCH. B MUST BE GREATER THAN OR EQUAL TO A. FOR CONTINUOUSLY ADJACENT VALUES OF (N
×
F
), AT THE OUTPUT, N
REF
IS (P2–P).
MIN
04644-018
ADF4360-0
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Table 9. R Counter Latch
RESERVED
RESERVED
THESE BITS ARE NOT USED BY THE DEVICE AND ARE DON'T CARE BITS.
BAND
SELECT
CLOCK
DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
DB21DB22DB23
BSC2RSVRSV
TEST MODE BIT SHOULD BE SET TO 0 FOR NORMAL OPERATION.
BIT
TEST
MODE
LDP LOCK DETECT PRECISION 0 THREE CONSECUTIVE CYCLES OF PHASE DELAY LESS THAN
1 FIVE CONSECUTIVE CYCLES OF PHASE DELAY LESS THAN
ANTI-
BACKLASH
PULSE
LOCK
DETECT
WIDTH
PRECISION
ABP2 ABP1 ANTIBACKLASH PULSE WIDTH 0 0 3.0ns 0 1 1.3ns 1 0 6.0ns 1 1 3.0ns
15ns MUST OCCUR BEFORE LOCK DETECT IS SET.
15ns MUST OCCUR BEFORE LOCK DETECT IS SET.
14-BIT REFERENCE COUNTER
R14 R13 R12 R3 R2 R1 DIVIDE RATIO
000 000 000
... ...
111 111 111
.......... 0000
.......... 0 1 1 2
.......... 0 1 0 3
.......... 1 0 1 4
.......... ....
.......... . . . .
.......... . . . .
.......... 1111
.......... 1 0 1 16381
.......... 1 1 0 16382
.......... 1 1 1 16383
00 1
.. .
0 0 16380
CONTROL
BITS
C2 (0) C1 (1)R1R2R3R4R5R7R8R9R10R11R12R13R14ABP1ABP2LDPTMBBSC1 R6
BSC2 BSC1 BAND SELECT CLOCK DIVIDER 001 012 104 118
04644-019
Rev. A | Page 15 of 24
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POWER-UP

Power-Up Sequence

The correct programming sequence for the ADF4360-0 after power-up is:
R counter latch
1.
Control latch
2.
3.
N counter latch

Initial Power-Up

Initial power-up refers to programming the part after the application of voltage to the AV initial power-up, an interval is required between programming the control latch and programming the N counter latch.
, DVDD, V
DD
, and CE pins. On
VCO
This interval is necessary to allow the transient behavior of the ADF4360-0 during initial power-up to have settled. During initial power-up, a write to the control latch powers up the part and the bias currents of the VCO begin to settle. If these cur­rents have not settled to within 10% of their steady-state value and if the N counter latch is then programmed, the VCO may not be able to oscillate at the desired frequency, which does not allow the band select logic to choose the correct frequency band and the ADF4360-0 may not achieve lock. If the recommended interval is inserted and the N counter latch is programmed, the band select logic can choose the correct frequency band and the part locks to the correct frequency.
This duration of this interval is affected by the value of the capacitor on the C
pin (Pin 14). This capacitor is used to
N
reduce the close-in noise of the ADF4360-0 VCO. The recom­mended value of this capacitor is 10 µF. Using this value requires an interval of ≥ 5 ms between the latching in of the control latch bits and latching in of the N counter latch bits. If a shorter delay is required, this capacitor can be reduced. A slight phase noise penalty is incurred by this change, which is ex­plained further in Table 10.
Table 10. CN Capacitance vs. Interval and Phase Noise
CN value Recommended Interval between Control Latch and N Counter Latch Open Loop Phase Noise @ 10 kHz Offset
10 µF ≥ 5 ms −84 dBc 440 nF ≥ 600 µs −82 dBc
POWER-UP
CLOCK
DATA
R COUNTER
LATCH DATA
LE
Figure 16. ADF4360-0 Power-Up Timing
CONTROL
LATCH DATA
N COUNTER
LATCH DATA
REQUIRED INTERVAL
CONTROL LATCH WRITE TO
N COUNTER LATCH WRITE
04644-020
Rev. A | Page 16 of 24
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Hardware Power-Up/Power-Down

If the ADF4360-0 is powered down via the hardware (using the CE pin) and powered up again without any change to the N counter register during power-down, it locks at the correct fre­quency because the part is already in the correct frequency band. The lock time depends on the value of capacitance on the
pin, which is <5 ms for 10 µF capacitance. The smaller
C
N
capacitance of 440 nF on this pin enables lock times of <600 µs.

Software Power-Up/Power-Down

If the ADF4360-0 is powered down via the software (using the control latch) and powered up again without any change to the N counter latch during power-down, it locks at the correct fre­quency because it is already in the correct frequency band. The lock time depends on the value of capacitance on the C which is <5 ms for 10 µF capacitance. The smaller capacitance of 440 nF on this pin enables lock times of <600 µs.
pin,
N
The N counter value cannot be changed while it is in power-
wn because the part may not lock to the correct frequency on
do power-up. If it is updated, the correct programming sequence for it after power-up is to the R counter latch, followed by the control latch, and finally the N counter latch, with the required interval between the control latch and N counter latch, as described in the Initial Power-Up section.
The N counter value cannot be changed while it is in power-
wn because the part may not lock to the correct frequency on
do power-up. If it is updated, the correct programming sequence for it after power-up is to the R counter latch, followed by the control latch, and finally the N counter latch, with the required interval between the control latch and N counter latch, as described in the Initial Power-Up section.
Rev. A | Page 17 of 24
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CONTROL LATCH

With (C2, C1) = (0, 0), the control latch is programmed. Table 7 shows the input data format for programming the control latch.

Prescaler Value

In the ADF4360 family, P2 and P1 in the control latch set the prescaler values.

Power-Down

DB21 (PD2) and DB20 (PD1) provide programmable power­down modes.
In the programmed asynchronous power-down, the device
owers down immediately after latching a 1 into Bit PD1, with
p the condition that PD2 has been loaded with a 0. In the pro­grammed synchronous power-down, the device power-down is gated by the charge pump to prevent unwanted frequency jumps. Once the power-down is enabled by writing a 1 into Bit PD1 (on the condition that a 1 has also been loaded to PD2), the device goes into power-down on the second rising edge of the R counter output, after LE goes high. When the CE pin is low, the device is immediately disabled regardless of the state of PD1 or PD2.
When a power-down is activated (either synchronous or
synchronous mode), the following events occur:
a
All active dc current paths are removed.
The R, N, and timeout counters are forced to their load
state conditions.
The charge pump is forced into three-state mode.
The digital lock detect circuitry is reset.
The RF outputs are debiased to a high impedance state.
The reference input buffer circuitry is disabled.
The input register remains active and capable of loading and
latching data.

Charge Pump Currents

CPI3, CPI2, and CPI1 in the ADF4360 family determine Current Setting 1.
CPI6, CPI5, and CPI4 determine Current Setting 2. See the
uth table in Table 7.
tr

Output Power Level

Bits PL1 and PL2 set the output power level of the VCO. See the truth table in Table 7.

Mute-Till-Lock Detect

DB11 of the control latch in the ADF4360 family is the mute-till­lock detect bit. This function, when enabled, ensures that the RF outputs are not switched on until the PLL is locked.

CP Gain

DB10 of the control latch in the ADF4360 family is the charge pump gain bit. When it is programmed to a 1, Current Setting 2 is used. When it is programmed to a 0, Current Setting 1 is used.

Charge Pump Three-State

This bit puts the charge pump into three-state mode when programmed to a 1. It should be set to 0 for normal operation.

Phase Detector Polarity

The PDP bit in the ADF4360 family sets the phase detector polarity. The positive setting enabled by programming a 1 is used when using the on-chip VCO with a passive loop filter or with an active non-inverting filter. It can also be set to 0. This is required, if an active inverting loop filter is used.

MUXOUT Control

The on-chip multiplexer is controlled by M3, M2, and M1. See the truth table in Table 7.

Counter Reset

DB4 is the counter reset bit for the ADF4360 family. When this is 1, the R counter and the A, B counters are reset. For normal operation, this bit should be 0.

Core Power Level

PC1 and PC2 set the power level in the VCO core. The recom­mended setting is 10 mA. See the truth table in Table 7.
Rev. A | Page 18 of 24
ADF4360-0
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N COUNTER LATCH

With (C2, C1) = (1, 0), the N counter latch is programmed. Table 8 shows the input data format for programming the N counter latch.

A Counter Latch

A5 to A1 program the 5-bit A counter. The divide range is 0 (00000) to 31 (11111).

Reserved Bits

DB7 is a spare bit that is reserved. It should be programmed to 0.

B Counter Latch

B13 to B1 program the B counter. The divide range is 3
(00.....0011) to 8191 (11....111).

Overall Divide Range

The overall divide range is defined by ((P × B) + A), where P is the prescaler value.

CP Gain

DB21 of the N counter latch in the ADF4360 family is the charge pump gain bit. When this is programmed to 1, Current Setting 2 is used. When programmed to 0, Current Setting 1 is used. This bit can also be programmed through DB10 of the control latch. The bit always reflects the latest value written to it, whether this is through the control latch or the N counter latch.

Divide-by-2

DB22 is the divide-by-2 bit. When set to 1, the output divide-by-2 function is chosen. When it is set to 0, normal operation occurs.

Divide-by-2 Select

DB23 is the divide-by-2 select bit. When programmed to 1, the divide-by-2 output is selected as the prescaler input. When set to 0, the fundamental is used as the prescaler input. For exam­ple, using the output divide-by-2 feature and a PFD frequency of 200 kHz, the user needs a value of N = 13,000 to generate 1,500 MHz. With the divide-by-2 select bit high, the user may keep N = 6,500.

R COUNTER LATCH

With (C2, C1) = (0, 1), the R counter latch is programmed. Table 9 shows the input data format for programming the R counter latch.

R Counter

R1 to R14 set the counter divide ratio. The divide range is 1
(00......001) to 16383 (111......111).

Antibacklash Pulse Width

DB16 and DB17 set the antibacklash pulse width.

Lock Detect Precision

DB18 is the lock detect precision bit. This bit sets the number of reference cycles with less than 15 ns phase error for entering the locked state. With LDP at 1, five cycles are taken; with LDP at 0, three cycles are taken.

Test Mode Bit

DB19 is the test mode bit (TMB) and should be set to 0. With TMB = 0, the contents of the test mode latch are ignored and normal operation occurs as determined by the contents of the control latch, R counter latch, and N counter latch. Note that test modes are for factory testing only and should not be pro­grammed by the user.

Band Select Clock

These bits set a divider for the band select logic clock input. The output of the R counter is by default the value used to clock the band select logic, but, if this value is too high (>1 MHz), a divider can be switched on to divide the R counter output to a smaller value (see Table 9).

Reserved Bits

DB23 to DB22 are spare bits that are reserved. They should be programmed to 0.
Rev. A | Page 19 of 24
ADF4360-0
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APPLICATIONS

FIXED FREQUENCY LO

Figure 17 shows the ADF4360-0 used as a fixed frequency LO at 2.6 GHz. The low-pass filter was designed using ADIsimPLL for a channel spacing of 8 MHz and an open-loop bandwidth of 40 kHz. The maximum PFD frequency of the ADF4360-0 is 8 MHz. Because using a larger PFD frequency allows users to use a smaller N, the in-band phase noise is reduced to as low as possible, –100 dBc/Hz. The 40 kHz bandwidth is chosen to be just greater than the point at which the open-loop phase noise of the VCO is –100 dBc/Hz, thus giving the best possible integrated noise. The typical rms phase noise (100 Hz to 100 kHz) of the LO in this con­figuration is 0.35°. The reference frequency is from a 16 MHz TCXO from Fox; thus, an R value of 2 is programmed. Taking into account the high PFD frequency and its effect on the band select logic, the band select clock divider is enabled. In this case, a value of 8 is chosen. A very simple pull-up resistor and dc blocking capaci­tor complete the RF output stage.
V
VCO
6
DVDDAVDDCE MUXOUT
V
VCO
14
C
N
1nF1nF
16
REF
IN
51
17
CLK
18
DATA
19
LE
12
C
13
R
CPGND AGND DGND
1
ADF4360-0
C
SET
3 8 9 10 11 22 15
FOX
801BE-160
16MHz
SPI COMPATIBLE SERIAL BUS
1nF
10µF
4.7k
Figure 17. Fixed Frequency LO

INTERFACING

The ADF4360 family has a simple SPI®-compatible serial inter­face for writing to the device. CLK, DATA, and LE control the data transfer. When LE goes high, the 24 bits that have been clocked into the appropriate register on each rising edge of CLK are transferred to the appropriate latch. See Figure 2 for the timing diagram and Table 5 for the latch truth table.
The maximum allowable serial clock rate is 20 MHz. This means that the maximum update rate possible is 833 kHz or one update every 1.2 µs. This is more than adequate for systems that have typical lock times in hundreds of microseconds.
LOCK
V
DETECT
VDD
2023221
V
7
TUNE
24
CP
A
4
RF
OUT
5
RF
B
OUT
3k
8.2nF
560pF 270pF
1.5k
V
VCO
51
51
100pF
100pF

ADuC812 Interface

Figure 18 shows the interface between the ADF4360 family and the ADuC812 MicroConverter®. Because the ADuC812 is based on an 8051 core, this interface can be used with any 8051 based microcontroller. The MicroConverter is set up for SPI master mode with CPHA = 0. To initiate the operation, the I/O port driving LE is brought low. Each latch of the ADF4360 family needs a 24-bit word, which is accomplished by writing three 8­bit bytes from the MicroConverter to the device. When the third byte has been written, the LE input should be brought high to complete the transfer.
SCLOCK
MOSI
ADuC812
I/O PORTS
Figure 18. ADuC812 to ADF4360-x Interface
SCLK SDATA
LE
ADF4360-x
CE MUXOUT
(LOCK DETECT)
04644-022
I/O port lines on the ADuC812 are also used to control power­down (CE input) and detect lock (MUXOUT configured as lock detect and polled by the port input). When operating in the described mode, the maximum SCLOCK rate of the ADuC812 is 4 MHz. This means that the maximum rate at which the out­put frequency can be changed is 166 kHz.

ADSP-21xx Interface

Figure 19 shows the interface between the ADF4360 family and the ADSP-21xx digital signal processor. The ADF4360 family needs a 24-bit serial word for each latch write. The easiest way
04644-021
to accomplish this using the ADSP-21xx family is to use the autobuffered transmit mode of operation with alternate fram­ing. This provides a means for transmitting an entire block of serial data before an interrupt is generated.
SCLOCK
MOSI
TFS
ADSP-21xx
I/O PORTS
Figure 19. ADSP-21xx to ADF4360-x Interface
SCLK SDATA
LE
ADF4360-x
CE MUXOUT
(LOCK DETECT)
04644-023
Set up the word length for 8 bits and use three memory loca­tions for each 24-bit word. To program each 24-bit latch, store the 8-bit bytes, enable the autobuffered mode, and write to the transmit register of the DSP. This last operation initiates the autobuffer transfer.
Rev. A | Page 20 of 24
ADF4360-0
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PCB DESIGN GUIDELINES FOR CHIP SCALE PACKAGE

The leads on the chip scale package (CP-24) are rectangular. The printed circuit board pad for these should be 0.1 mm longer than the package lead length and 0.05 mm wider than the package lead width. The lead should be centered on the pad to ensure that the solder joint size is maximized.
The bottom of the chip scale package has a central thermal pad. The thermal pad on the printed circuit board should be at least as large as this exposed pad. On the printed circuit board, there should be a clearance of at least 0.25 mm between the thermal pad and the inner edges of the pad pattern to ensure that short­ing is avoided.
Thermal vias may be used on the printed circuit board thermal pad to improve thermal performance of the package. If vias are used, they should be incorporated in the thermal pad at a
1.2 mm pitch grid. The via diameter should be between 0.3 mm and 0.33 mm, and the via barrel should be plated with 1 ounce of copper to plug the via.
Experiments have shown that the circuit shown in Figure 21 provides an excellent match to 50 Ω over the operating range of the ADF4360-0. This gives approximately −4 dBm output power across the frequency range of the ADF4360-0. Both single­ended architectures can be examined using the EVAL­ADF4360-0EB1 evaluation board.
V
VCO
47nH
3.9nH
RF
OUT
Figure 21. Differential ADF4360-0 Output Stage
1.5pF
50
04644-025
If the user does not need the differential outputs available on the ADF4360-0, the user may either terminate the unused out­put or combine both outputs using a balun. The circuit in Figure 22 shows how best to combine the outputs.
V
VCO
The user should connect the printed circuit thermal pad to AGND. This is internally connected to AGND.

OUTPUT MATCHING

There are a number of ways to match the output of the ADF4360-0 for optimum operation; the most basic is to use a 50 Ω resistor to V nected in series, as shown in Figure 20. Because the resistor is not frequency dependent, this provides a good broadband match. The output power in this circuit typically gives −6.5 dBm output power into a 50 Ω load.
A better solution is to use a shunt inductor (acting as an RF choke) to V
VCO
therefore, more output power. Additionally, a series inductor is added after the dc bypass capacitor to provide a resonant LC circuit. This tunes the oscillator output and provides approxi­mately 10 dB additional rejection of the second harmonic. The shunt inductor needs to be a relatively low value (<10 nH).
. A dc bypass capacitor of 100 pF is con-
VCO
V
VCO
51
RF
OUT
Figure 20. Simple ADF4360-1 Output Stage
100pF
50
04644-024
. This gives a better match than a resistor and,
1nH
A
RF
OUT
RF
OUT
Figure 22. Balun for Combining ADF4360-0 RF Outputs
1nH
B
3.6nH
1.5pF
3.6nH
1.5pF
47nH
10pF
50
04644-026
The circuit in Figure 22 is a lumped-lattice-type LC balun. It is designed for a center frequency of 2.6 GHz and outputs −1 dBm at this frequency. The series 1 nH inductor is used to tune out any parasitic capacitance due to the board layout from each input, and the remainder of the circuit is used to shift the output of one RF input by +90° and the second by −90°, thus combining the two. The action of the 3.6 nH inductor and the
1.5 pF capacitor accomplishes this. The 12 nH is used to provide an RF choke to feed the supply voltage, and the 10 pF capacitor provides the necessary dc block. To ensure good RF perform­ance, the circuits in Figure 20 and Figure 22 are implemented with Coilcraft 0402/0603 inductors and AVX 0402 thin-film capacitors.
Alternatively, instead of the LC balun shown in Figure 22, both outputs may be combined using a 180° rat-race coupler.
Rev. A | Page 21 of 24
ADF4360-0
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OUTLINE DIMENSIONS

0.60 MAX
19
18
EXPOSED
(BOTTOMVIEW)
13
12
PA D
24
6
7
1
2.50 REF
PIN 1 INDICATOR
2.45
2.30 SQ
2.15
0.23 MIN
*
PIN 1
INDICATOR
1.00
0.85
0.80
SEATING PLANE
12° MAX
4.00
BSC SQ
TOP
VIEW
0.80 MAX
0.65 TYP
*
COMPLIANT TO JEDEC STANDARDS MO-220-VGGD-2 EXCEPT FOR EXPOSED PAD DIMENSION
0.30
0.23
0.18
3.75
BSC SQ
0.20 REF
0.05 MAX
0.02 NOM COPLANARITY
0.60 MAX
0.50 BSC
0.50
0.40
0.30
0.08
Figure 23. 24-Lead Lead Frame Chip Scale Package [VQ_LFCSP]
4 mm × 4 mm Body, Very Thin Quad (CP-24-2)
Dimensions shown in millimeters

ORDERING GUIDE

Model Temperature Range Frequency Range Package Option
ADF4360-0BCP −40°C to +85°C 2400 MHz to 2725 MHz CP-24-2 ADF4360-0BCPRL −40°C to +85°C 2400 MHz to 2725 MHz CP-24-2 ADF4360-0BCPRL7 −40°C to +85°C 2400 MHz to 2725 MHz CP-24-2 ADF4360-0BCPZ ADF4360-0BCPZRL1 −40°C to +85°C 2400 MHz to 2725 MHz CP-24-2 ADF4360-0BCPZRL71 −40°C to +85°C 2400 MHz to 2725 MHz CP-24-2 EVAL-ADF4360-0EB1 Evaluation Board
1
Z = Pb-free model.
1
−40°C to +85°C 2400 MHz to 2725 MHz CP-24-2
Rev. A | Page 22 of 24
ADF4360-0
www.BDTIC.com/ADI
NOTES
Rev. A | Page 23 of 24
ADF4360-0
www.BDTIC.com/ADI
NOTES
Purchase of licensed I2C components of Analog Devices or one of its sublicensed Associated Companies conveys a license for the purchaser under the Philips I2C Patent Rights to use these components in an I2C system, provided that the system conforms to the I2C Standard Specification as defined by Philips.
© 2004 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners.
D04644–0–12/04(A)
Rev. A | Page 24 of 24
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