ADF4153 [ADI]

Fractional-N Frequency Synthesizer; 小数N分频合成器
ADF4153
型号: ADF4153
厂家: ADI    ADI
描述:

Fractional-N Frequency Synthesizer
小数N分频合成器

文件: 总24页 (文件大小:257K)
中文:  中文翻译
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Fractional-N Frequency Synthesizer  
ADF4153  
FEATURES  
GENERAL DESCRIPTION  
RF bandwidth 500 MHz to 4 GHz  
2.7 V to 3.3 V power supply  
The ADF4153 is a fractional-N frequency synthesizer that  
implements local oscillators in the upconversion and  
downconversion sections of wireless receivers and transmitters.  
It consists of a low noise digital phase frequency detector  
(PFD), a precision charge pump, and a programmable reference  
divider. There is a Σ-Δ based fractional interpolator to allow  
programmable fractional-N division. The INT, FRAC, and  
MOD registers define an overall N divider (N = (INT +  
(FRAC/MOD))). In addition, the 4-bit reference counter (R  
counter) allows selectable REFIN frequencies at the PFD input.  
A complete phase-locked loop (PLL) can be implemented if the  
synthesizer is used with an external loop filter and a voltage  
controlled oscillator (VCO).  
Separate VP allows extended tuning voltage  
Programmable dual-modulus prescaler 4/5, 8/9  
Programmable charge pump currents  
3-wire serial interface  
Analog and digital lock detect  
Power-down mode  
Pin compatible with the  
ADF4110/ADF4111/ADF4112/ADF4113 and ADF4106  
Programmable modulus on fractional-N synthesizer  
Trade-off noise versus spurious performance  
APPLICATIONS  
CATV equipment  
Base stations for mobile radio (GSM, PCS, DCS,  
CDMA, WCDMA)  
Wireless handsets (GSM, PCS, DCS, CDMA, WCDMA)  
Wireless LANs  
Control of all on-chip registers is via a simple 3-wire interface.  
The device operate with a power supply ranging from 2.7 V to  
3.3 V and can be powered down when not in use.  
Communications test equipment  
FUNCTIONAL BLOCK DIAGRAM  
AV  
DV  
V
SDV  
R
SET  
DD  
DD  
P
DD  
ADF4153  
REFERENCE  
4-BIT  
R COUNTER  
×2  
REF  
IN  
DOUBLER  
+
PHASE  
CP  
CHARGE  
PUMP  
FREQUENCY  
DETECTOR  
V
DD  
HIGH Z  
DGND  
LOCK  
DETECT  
CURRENT  
SETTING  
OUTPUT  
MUX  
MUXOUT  
V
R
N
DD  
DIV  
RFCP3 RFCP2 RFCP1  
DIV  
RF  
RF  
A
B
IN  
N-COUNTER  
IN  
THIRD ORDER  
FRACTIONAL  
INTERPOLATOR  
CLOCK  
DATA  
LE  
FRACTION  
REG  
MODULUS  
REG  
INTEGER  
REG  
24-BIT  
DATA  
REGISTER  
AGND  
DGND  
CPGND  
Figure 1.  
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  
Fax: 781.326.8703  
www.analog.com  
© 2004 Analog Devices, Inc. All rights reserved.  
ADF4153  
TABLE OF CONTENTS  
Specifications..................................................................................... 3  
R Divider Register, R1................................................................ 17  
Control Register, R2 ................................................................... 17  
Noise and Spur Register, R3...................................................... 18  
Reserved Bits............................................................................... 18  
RF Synthesizer: A Worked Example ........................................ 18  
Modulus....................................................................................... 19  
Reference Doubler and Reference Divider ............................. 19  
12-Bit Programmable Modulus................................................ 19  
Spurious Optimization and Fastlock ....................................... 19  
Phase Resync and Spur Consistency ....................................... 19  
Spurious Signals—Predicting Where They Will Appear....... 20  
Filter Design—ADIsimPLL....................................................... 20  
Interfacing ................................................................................... 20  
PCB Design Guidelines for Chip Scale Package .................... 21  
Outline Dimensions....................................................................... 22  
Ordering Guide .......................................................................... 22  
Timing Characteristics..................................................................... 5  
Absolute Maximum Ratings............................................................ 6  
ESD Caution.................................................................................. 6  
Pin Configuration and Pin Function Descriptions...................... 7  
Typical Performance Characteristics ............................................. 8  
Circuit Description......................................................................... 10  
Reference Input Section............................................................. 10  
RF Input Stage............................................................................. 10  
RF INT Divider........................................................................... 10  
INT, FRAC, MOD, and R Relationship.................................... 10  
RF R COUNTER ........................................................................ 10  
Phase Frequency Detector (PFD) and Charge Pump............ 11  
MUXOUT and LOCK Detect................................................... 11  
Input Shift Registers................................................................... 11  
Program Modes .......................................................................... 11  
N Divider Register, R0 ............................................................... 17  
REVISION HISTORY  
1/04—Data Sheet Changed from a REV. 0 to a REV. A  
Renumbered Figures and Tables.............................. UNIVERSAL  
Changes to Specifications............................................................... 3  
Changes to Pin Function Description .......................................... 7  
Changes to RF Power-Down section ..........................................17  
Changes to PCB Design Guidelines for Chip Scale  
Package section ..............................................................................21  
Updated Outline Dimensions......................................................22  
Updated Ordering Guide..............................................................22  
7/03—Revision 0: Initial Version  
Rev. A | Page 2 of 24  
ADF4153  
SPECIFICATIONS1  
AVDD = DVDD = SDVDD = 2.7 V to 3.3 V; VP = AVDD to 5.5 V; AGND = DGND = 0 V; TA = TMIN to TMAX, unless otherwise noted; dBm  
referred to 50 Ω.  
Table 1.  
Parameter  
B Version  
Unit  
Test Conditions/Comments  
RF CHARACTERISTICS (3 V)  
RF Input Frequency (RFIN)2  
See Figure 17 for input circuit.  
−8 dBm/0 dBm min/max. For lower frequencies,  
ensure slew rate (SR) > 396 V/µs.  
0.5/4.0  
1.0/4.0  
GHz min/max  
GHz min/max  
−10 dBm/0 dBm min/max.  
REFERENCE CHARACTERISTICS  
REFIN Input Frequency2  
See Figure 16 for input circuit.  
For f < 10 MHz, use a dc-coupled CMOS compatible  
square wave, slew rate > 21 V/µs.  
10/250  
MHz min/max  
REFIN Input Sensitivity  
0.7/AVDD  
0 to AVDD  
10  
V p-p min/max  
V max  
pF max  
AC-coupled.  
CMOS compatible.  
REFIN Input Capacitance  
REFIN Input Current  
PHASE DETECTOR  
Phase Detector Frequency3  
CHARGE PUMP  
100  
µA max  
32  
MHz max  
ICP Sink/Source  
High Value  
Low Value  
Absolute Accuracy  
RSET Range  
ICP Three-State Leakage Current  
Matching  
ICP vs. VCP  
ICP vs. Temperature  
LOGIC INPUTS  
Programmable. See Table 5.  
With RSET = 5.1 kΩ.  
5
mA typ  
µA typ  
% typ  
kΩ min/max  
nA typ  
% typ  
312.5  
2.5  
1.5/10  
1
2
2
2
With RSET = 5.1 kΩ.  
Sink and source current.  
0.5 V < VCP < VP – 0.5.  
0.5 V < VCP < VP – 0.5.  
VCP = VP/2.  
% typ  
% typ  
VINH, Input High Voltage  
VINL, Input Low Voltage  
IINH/IINL, Input Current  
CIN, Input Capacitance  
LOGIC OUTPUTS  
VOH, Output High Voltage  
VOL, Output Low Voltage  
POWER SUPPLIES  
AVDD  
1.4  
0.6  
1
V min  
V max  
µA max  
pF max  
10  
1.4  
0.4  
V min  
V max  
Open-drain 1 kΩ pull-up to 1.8 V.  
IOL = 500 µA.  
2.7/3.3  
AVDD  
AVDD/5.5  
24  
V min/V max  
DVDD, SDVDD  
VP  
IDD  
V min/V max  
mA max  
4
20 mA typical.  
Low Power Sleep Mode  
NOISE CHARACTERISTICS  
Phase Noise Figure of Merit5  
ADF4153 Phase Noise Floor6  
1
µA typ  
−217  
−147  
−143  
dBc/Hz typ  
dBc/Hz typ  
dBc/Hz typ  
@ 10 MHz PFD frequency.  
@ 26 MHz PFD frequency.  
@ VCO output.  
Phase Noise Performance7  
1750 MHz Output8  
−106  
dBc/Hz typ  
@ 1 kHz offset, 26 MHz PFD frequency.  
See footnotes on next page.  
Rev. A | Page 3 of 24  
 
ADF4153  
1 Operating temperature is B version: −40°C to +80°C.  
2 Use a square wave for frequencies below fMIN  
.
3 Guaranteed by design. Sample tested to ensure compliance.  
4 AC coupling ensures AVDD/2 bias. See Figure 16 for typical circuit.  
5 This figure can be used to calculate phase noise for any application. Use the formula –217 + 10log(fPFD) + 20logN to calculate in-band phase noise performance as seen  
at the VCO output. The value given is the lowest noise mode.  
6 The synthesizer phase noise floor is estimated by measuring the in-band phase noise at the output of the VCO and subtracting 20logN (where N is the N divider value).  
The value given is the lowest noise mode.  
7 The phase noise is measured with the EVAL-ADF4153EB1 evaluation board and the HP8562E spectrum analyzer.  
8 fREFIN = 26 MHz; fPFD = 10 MHz; offset frequency = 1 kHz; RFOUT = 1750 MHz; N = 175; loop B/W = 20 kHz; lowest noise mode.  
Rev. A | Page 4 of 24  
 
ADF4153  
TIMING CHARACTERISTICS1  
AVDD = DVDD = SDVDD = 2.7 V to 3.3 V; VP = AVDD to 5.5 V; AGND = DGND = 0 V; TA = TMIN to TMAX, unless otherwise noted; dBm  
referred to 50 Ω.  
Table 2.  
Parameter  
Limit at TMIN to TMAX (B Version)  
Unit  
Test Conditions/Comments  
LE Setup Time  
t1  
t2  
t3  
t4  
t5  
t6  
t7  
20  
10  
10  
25  
25  
10  
20  
ns min  
ns min  
ns min  
ns min  
ns min  
ns min  
ns min  
DATA to CLOCK Setup Time  
DATA to CLOCK Hold Time  
CLOCK High Duration  
CLOCK Low Duration  
CLOCK to LE Setup Time  
LE Pulse Width  
1 Guaranteed by design but not production tested.  
t4  
t5  
CLOCK  
t2  
t3  
DB1  
(CONTROL BIT C2)  
DB0 (LSB)  
(CONTROL BIT C1)  
DB23 (MSB)  
DB22  
DB2  
DATA  
LE  
t7  
t1  
t6  
LE  
Figure 2. Timing Diagram  
Rev. A | Page 5 of 24  
 
 
ADF4153  
ABSOLUTE MAXIMUM RATINGS1, 2, 3, 4  
TA = 25°C, unless otherwise noted.  
Table 3.  
Parameter  
Rating  
VDD to GND  
−0.3 V to +4 V  
VDD to VDD  
VP to GND  
VP to VDD  
Digital I/O Voltage to GND  
Analog I/O Voltage to GND  
REFIN, RFIN to GND  
−0.3 V to +0.3 V  
−0.3 V to +5.8 V  
−0.3 V to +5.8 V  
−0.3 V to VDD + 0.3 V  
−0.3 V to VDD + 0.3 V  
−0.3 V to VDD + 0.3 V  
Operating Temperature Range  
Industrial (B Version)  
−40°C to +85°C  
−65°C to +150°C  
150°C  
150.4°C/W  
122°C/W  
Storage Temperature Range  
Maximum Junction Temperature  
TSSOP θJA Thermal Impedance  
LFCSP θJA Thermal Impedance (Paddle Soldered)  
LFCSP θJA Thermal Impedance (Paddle Not Soldered)  
Lead Temperature, Soldering  
Vapor Phase (60 sec)  
216°C/W  
215°C  
220°C  
Infrared  
1 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 listed in the operational sections of this specification is not implied. Exposure to absolute maximum rating  
conditions for extended periods may affect device reliability.  
2 This device is a high performance RF integrated circuit with an ESD rating of < 2 kV, and it is ESD sensitive. Proper precautions should be taken for handling and  
assembly.  
3 GND = AGND = DGND = 0 V.  
4 VDD = AVDD = DVDD = SDVDD  
.
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  
 
 
 
 
ADF4153  
PIN CONFIGURATION AND PIN FUNCTION DESCRIPTIONS  
R
1
2
3
4
5
6
7
8
16  
V
P
SET  
CP  
15 DV  
DD  
PIN 1  
15 MUXOUT  
14 LE  
13 DATA  
12 CLK  
11 SDV  
DD  
CPGND  
AGND  
AGND  
1
2
3
4
5
INDICATOR  
CPGND  
AGND  
14 MUXOUT  
13 LE  
ADF4153  
TOP VIEW  
ADF4153  
RF  
RF  
B
A
TOP VIEW  
IN  
IN  
RF  
B
A
12 DATA  
11 CLK  
IN  
IN  
(Not to Scale)  
RFI  
AV  
DD  
10 SDV  
DD  
REF  
IN  
9 DGND  
Figure 3. TSSOP Pin Configuration  
Figure 4. LFCSP Pin Configuration  
Table 4. Pin Function Descriptions  
TSSOP  
LFCSP  
Mnemonic Description  
1
19  
RSET  
Connecting a resistor between this pin and ground sets the maximum charge pump output current.  
The relation ship between ICP and RSET is  
25.5  
RSET  
ICP max  
=
With RSET = 5.1 kΩ, ICPmax = 5 mA.  
2
20  
CP  
Charge Pump Output. When enabled, this provides ICP to the external loop filter, which in turn drives  
the external VCO.  
3
4
5
1
2, 3  
4
CPGND  
AGND  
RFINB  
Charge Pump Ground. This is the ground return path for the charge pump.  
Analog Ground. This is the ground return path of the prescaler.  
Complementary Input to the RF Prescaler. This point should be decoupled to the ground plane with a  
small bypass capacitor, typically 100 pF (see Figure 17).  
6
7
5
6, 7  
RFINA  
AVDD  
Input to the RF Prescaler. This small-signal input is normally ac-coupled from the VCO.  
Positive Power Supply for the RF Section. Decoupling capacitors to the digital ground plane should be  
placed as close as possible to this pin. AVDD has a value of 3 V 10%. AVDD must have the same voltage  
as DVDD  
.
8
8
REFIN  
Reference Input. This is a CMOS input with a nominal threshold of VDD/2 and an equivalent input  
resistance of 100 kΩ (see Figure 16). This input can be driven from a TTL or CMOS crystal oscillator, or it  
can be ac-coupled.  
9
10  
9, 10  
11  
DGND  
SDVDD  
Digital Ground.  
∑-∆ Power. Decoupling capacitors to the digital ground plane should be placed as close as possible to  
this pin. SDVDD has a value of 3 V 10%. SDVDD must have the same voltage as DVDD  
.
11  
12  
13  
14  
15  
12  
CLK  
Serial Clock Input. This serial clock is used to clock in the serial data to the registers. The data is latched  
into the shift register on the CLK rising edge. This input is a high impedance CMOS input.  
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.  
Load Enable, CMOS Input. When LE is high, the data stored in the shift registers is loaded into one of  
the four latches, the latch being selected using the control bits.  
This multiplexer output allows either the RF lock detect, the scaled RF, or the scaled reference  
frequency to be accessed externally.  
13  
DATA  
LE  
14  
15  
MUXOUT  
DVDD  
16, 17  
Positive Power Supply for the Digital Section. Decoupling capacitors to the digital ground plane should  
be placed as close as possible to this pin. DVDD has a value of 3 V 10%. DVDD must have the same  
voltage as AVDD  
.
16  
18  
VP  
Charge Pump Power Supply. This should be greater than or equal to VDD. In systems where VDD is 3 V, it  
can be set to 5.5 V and used to drive a VCO with a tuning range of up to 5.5 V.  
Rev. A | Page 7 of 24  
ADF4153  
TYPICAL PERFORMANCE CHARACTERISTICS  
Figure 5 to Figure 10: RFOUT = 1.722 GHz, PFD Freq = 26 MHz, INT = 66, Channel Spacing = 200 kHz, Modulus = 130, Fraction = 1/130,  
and ICP = 5 mA.  
Loop Bandwidth = 20 kHz, Reference = Fox 10 MHz TCXO, VCO = Vari-L VCO190-1750T, Eval Board = Eval-ADF4153EB1,  
measurements taken on HP8562E spectrum analyzer.  
0
–10  
–20  
–30  
–40  
–50  
–60  
–70  
–80  
–90  
–100  
0
–10  
–20  
–30  
–40  
–50  
–60  
–70  
–80  
–90  
–100  
V
= 3V, V = 5V  
P
DD  
= 5mA  
V
= 3V, V = 5V  
P
DD  
I = 5mA  
CP  
I
CP  
REFERENCE  
LEVEL = –4.2dBm  
REFERENCE  
LEVEL = –4dBm  
PFD FREQUENCY = 26MHz  
CHANNEL STEP = 200kHz  
LOOP BANDWIDTH = 20kHz  
LOWEST NOISE MODE  
N = 66 1/130  
PFD FREQUENCY = 26MHz  
CHANNEL STEP = 200kHz  
LOOP BANDWIDTH = 20kHz  
LOWEST NOISE MODE  
N = 66 1/130  
RBW = 10Hz  
RBW = 10Hz  
–71dBc@200kHz  
–102dBc/Hz  
–400kHz  
–200kHz  
1.722GHz  
200kHz  
400kHz  
–2kHz  
–1kHz  
1.722GHz  
1kHz  
2kHz  
Figure 5. Phase Noise (Lowest Noise Mode)  
Figure 8. Spurs (Lowest Noise Mode)  
0
–10  
–20  
–30  
–40  
–50  
–60  
–70  
–80  
0
–10  
–20  
–30  
–40  
–50  
–60  
–70  
–80  
–90  
–100  
V
= 3V, V = 5V  
P
DD  
= 5mA  
V
I
= 3V, V = 5V  
P
DD  
= 5mA  
I
CP  
REFERENCE  
LEVEL = –4.2dBm  
REFERENCE  
LEVEL = –4.2dBm  
CP  
PFD FREQUENCY = 26MHz  
CHANNEL STEP = 200kHz  
LOOP BANDWIDTH = 20kHz  
LOW NOISE AND  
PFD FREQUENCY = 26MHz  
CHANNEL STEP = 200kHz  
LOOP BANDWIDTH = 20kHz  
LOW NOISE AND  
SPUR MODE  
SPUR MODE  
N = 66 1/130  
RBW = 10Hz  
N = 66 1/130  
RBW = 10Hz  
–74dBc@200kHz  
–95dBc/Hz  
–90  
–100  
–2kHz  
–1kHz  
1.722GHz  
1kHz  
2kHz  
–400kHz  
–200kHz  
1.722GHz  
200kHz  
400kHz  
Figure 6. Phase Noise (Low Noise Mode and Spur Mode)  
Figure 9. Spurs (Low Noise and Spur Mode)  
0
–10  
–20  
–30  
–40  
–50  
–60  
–70  
–80  
–90  
–100  
0
–10  
–20  
–30  
–40  
–50  
–60  
–70  
–80  
–90  
–100  
V
= 3V, V = 5V  
P
DD  
I = 5mA  
CP  
V
I
= 3V, V = 5V  
P
DD  
= 5mA  
REFERENCE  
LEVEL = –4.2dBm  
REFERENCE  
LEVEL = –4.2dBm  
CP  
PFD FREQUENCY = 26MHz  
CHANNEL STEP = 200kHz  
LOOP BANDWIDTH = 20kHz  
LOWEST SPUR NOISE  
N = 66 1/130  
PFD FREQUENCY = 26MHz  
CHANNEL STEP = 200kHz  
LOOP BANDWIDTH = 20kHz  
LOWEST SPUR MODE  
N = 66 1/130  
RBW = 10Hz  
RBW = 10Hz  
–90dBc/Hz  
–2kHz  
–1kHz  
1.722GHz  
1kHz  
2kHz  
–400kHz  
–200kHz  
1.722GHz  
200kHz  
400kHz  
Figure 7. Phase Noise (Lowest Spur Mode)  
Figure 10. Spurs (Lowest Spur Mode)  
Rev. A | Page 8 of 24  
 
 
ADF4153  
–130  
–140  
–150  
–160  
–170  
–80  
–85  
–90  
–95  
–100  
–105  
–110  
0
5
10  
15  
20  
25  
30  
35  
100  
1000  
10000  
100000  
R
VALUE (k)  
SET  
PHASE DETECTOR FREQUENCY (kHz)  
Figure 11. PFD Noise Floor vs. PFD Frequency (Lowest Noise Mode)  
Figure 14. Phase Noise vs. RSET  
5
–90  
–92  
–94  
–96  
0
–5  
–10  
–15  
–20  
–25  
–30  
–35  
P = 4/5  
–98  
–100  
P = 8/9  
–102  
0
0.5  
1.0  
1.5  
2.0  
2.5  
3.0  
3.5  
4.0  
4.5  
–104  
–60  
–40  
–20  
0
20  
40  
60  
80  
100  
FREQUENCY (GHz)  
TEMPERATURE(°C)  
Figure 12. RF Input Sensitivity  
Figure 15. Phase Noise vs. Temperature  
6
5
4
3
2
1
0
–1  
–2  
–3  
–4  
–5  
–6  
0
1
2
3
4
5
V
(V)  
CP  
Figure 13. Charge Pump Output Characteristics  
Rev. A | Page 9 of 24  
ADF4153  
CIRCUIT DESCRIPTION  
REFERENCE INPUT SECTION  
INT, FRAC, MOD, AND R RELATIONSHIP  
The reference input stage is shown in Figure 16. 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 REFIN pin  
on power-down.  
The INT, FRAC, and MOD values, in conjunction with the  
R counter, make it possible to generate output frequencies that  
are spaced by fractions of the phase frequency detector (PFD).  
See the RF Synthesizer: A Worked Example section for more  
information. The RF VCO frequency (RFOUT) equation is  
POWER-DOWN  
CONTROL  
RFOUT = FPFD  
×
(
INT +  
(
FRAC MOD
))  
(1)  
100k  
where RFOUT is the output frequency of external voltage  
NC  
SW2  
controlled oscillator (VCO).  
TO R COUNTER  
REF  
IN  
NC  
SW1  
BUFFER  
FPFD = REFIN  
where:  
×
(
1 + D R  
)
(2)  
SW3  
NO  
Figure 16. Reference Input Stage  
REFIN is the reference input frequency.  
D is the REFIN doubler bit.  
RF INPUT STAGE  
The RF input stage is shown in Figure 17. It is followed by a  
2-stage limiting amplifier to generate the current mode logic  
(CML) clock levels needed for the prescaler.  
R is the preset divide ratio of binary 4-bit programmable  
reference counter (1 to 15).  
1.6V  
INT is the preset divide ratio of binary 9-bit counter (31 to 511).  
BIAS  
GENERATOR  
AV  
DD  
MOD is the preset modulus ratio of binary 12-bit  
programmable FRAC counter (2 to 4095).  
2k  
2kΩ  
FRAC is the preset fractional ratio of binary 12-bit  
programmable FRAC counter (0 to MOD).  
RF  
RF  
A
B
IN  
RF R COUNTER  
The 4-bit RF R counter allows the input reference frequency  
(REFIN) to be divided down to produce the reference clock to  
the PFD. Division ratios from 1 to 15 are allowed.  
IN  
RF N DIVIDER  
N = INT + FRAC/MOD  
AGND  
FROM RF  
TO PFD  
INPUT STAGE  
N-COUNTER  
Figure 17. RF Input Stage  
THIRD ORDER  
FRACTIONAL  
INTERPOLATOR  
RF INT DIVIDER  
The RF INT CMOS counter allows a division ratio in the PLL  
feedback counter. Division ratios from 31 to 511 are allowed.  
INT  
REG  
MOD  
REG  
FRAC  
VALUE  
Figure 18. A and B Counters  
Rev. A | Page 10 of 24  
 
 
ADF4153  
PHASE FREQUENCY DETECTOR (PFD) AND  
CHARGE PUMP  
INPUT SHIFT REGISTERS  
The ADF4153 digital section includes a 4-bit RF R counter, a 9-  
bit RF N counter, a 12-bit FRAC counter, and a 12-bit modulus  
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 and C1) in the shift register.  
These are the 2 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.  
The PFD takes inputs from the R counter and N counter and  
produces an output proportional to the phase and frequency  
difference between them. Figure 19 is a simplified schematic.  
The PFD includes a fixed delay element that sets the width of  
the antibacklash pulse, which is typically 3 ns. This pulse  
ensures that there is no dead zone in the PFD transfer function,  
and gives a consistent reference spur level.  
UP  
HI  
D1  
Q1  
U1  
CLR1  
+IN  
PROGRAM MODES  
Table 5 through Table 10 show how to set up the program  
modes in the ADF4153.  
CHARGE  
PUMP  
CP  
U3  
DELAY  
DOWN  
The ADF4153 programmable modulus is double buffered. This  
means that two events have to occur before the part uses a new  
modulus value. First, the new modulus value is latched into the  
device by writing to the R divider register. Second, a new write  
must be performed on the N divider register. Therefore, any  
time that the modulus value has been updated, the N divider  
register must be written to after this, to ensure that the modulus  
value is loaded correctly.  
CLR2  
D2 Q2  
HI  
U2  
–IN  
Figure 19. PFD Simplified Schematic  
MUXOUT AND LOCK DETECT  
Table 5. C2 and C1 Truth Table  
Control Bits  
The output multiplexer on the ADF4153 allows the user to  
access various internal points on the chip. The state of  
MUXOUT is controlled by M3, M2, and M1 (see Table 8).  
Figure 20 shows the MUXOUT section in block diagram form.  
C2  
0
0
1
1
C1  
0
1
0
1
Register  
N Divider Register  
R Divider Register  
Control Register  
Noise and Spur Register  
The N-channel open-drain analog lock detect should be  
operated with an external pull-up resistor of 10 kΩ nominal.  
When lock has been detected, it is high with narrow low-going  
pulses.  
DV  
DD  
THREE-STATE OUTPUT  
LOGIC LOW  
DIGITAL LOCK DETECT  
R COUNTER OUTPUT  
N COUNTER OUTPUT  
ANALOG LOCK DETECT  
LOGIC HIGH  
MUXOUT  
MUX  
CONTROL  
DGND  
Figure 20. MUXOUT Schematic  
Rev. A | Page 11 of 24  
 
 
 
ADF4153  
Table 6. Register Summary  
N DIVIDER REG  
CONTROL  
BITS  
9-BIT INTEGER VALUE (INT)  
12-BIT FRACTIONAL VALUE (FRAC)  
DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10  
DB9 DB8  
F8 F7  
DB7  
F6  
DB6  
F5  
DB5  
F4  
DB4 DB3 DB2  
F3 F2 F1  
DB1  
DB0  
FL1  
N9  
N8  
N7  
N6  
N5  
N4  
N3  
N2  
N1  
F12  
F11  
F10  
F9  
C2 (0) C1 (0)  
R DIVIDER REG  
4-BIT  
R COUNTER  
CONTROL  
BITS  
MUXOUT  
12-BIT INTERPOLATOR MODULUS VALUE (MOD)  
DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9  
P3 M3 M2 M1 P2 P1 R4 R3 R2 R1 M12 M11 M10 M9 M8  
DB8  
M7  
DB7  
M6  
DB6  
M5  
DB5  
M4  
DB4 DB3 DB2  
DB1 DB0  
M3  
M2  
M1  
C2 (0) C1 (1)  
CONTROL REG  
CP CURRENT  
SETTING  
CONTROL  
BITS  
RESYNC  
DB15 DB14 DB13 DB12 DB11 DB10  
DB9  
CP2  
DB8  
CP1  
DB7  
CP0  
DB6  
U5  
DB5  
U4  
DB4  
U3  
DB3  
U2  
DB2  
U1  
DB1  
DB0  
S4  
S3  
S2  
S1  
U6  
CP3  
C2 (1) C1 (0)  
NOISE AND SPUR REG  
CONTROL  
BITS  
NOISE AND SPUR  
MODE  
RESERVED  
DB10  
T9  
DB9  
T8  
DB8  
T7  
DB7 DB6 DB5  
T6 T5 T4  
DB4  
T3  
DB3  
T2  
DB2  
T1  
DB1 DB0  
C2 (1) C1 (1)  
Rev. A | Page 12 of 24  
ADF4153  
Table 7. N Divider Register Map  
CONTROL  
BITS  
9-BIT INTEGER VALUE (INT)  
12-BIT FRACTIONAL VALUE (FRAC)  
DB23 DB22  
N9  
DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9  
DB8  
F7  
DB7  
F6  
DB6  
F5  
DB5  
F4  
DB4 DB3 DB2  
F3 F2 F1  
DB1  
DB0  
N8  
N7  
N6  
N5  
N4  
N3  
N2  
N1  
C2 (0) C1 (0)  
FL1  
F8  
F12  
F11  
F10  
F9  
F12  
F11  
F10  
F3  
F2  
F1  
FRACTIONAL VALUE (FRAC)  
0
0
0
0
.
.
.
1
0
0
0
0
.
.
.
1
0
0
0
0
.
.
.
1
..........  
..........  
..........  
..........  
..........  
..........  
..........  
..........  
0
0
0
0
.
.
.
1
0
0
1
1
.
.
.
0
0
1
0
1
.
.
.
0
0
1
2
3
.
.
.
4092  
1
1
1
1
1
1
1
1
1
..........  
..........  
..........  
1
1
1
0
1
1
1
0
1
4093  
4094  
4095  
N9  
N8  
N7  
N6  
N5  
N4  
N3  
N2  
N1  
INTEGER VALUE (INT)  
0
0
0
0
0
0
0
1
1
0
1
0
1
0
1
0
1
0
31  
32  
0
0
.
0
0
.
0
0
.
1
1
.
0
0
.
0
0
.
0
0
.
0
1
.
1
0
.
33  
34  
.
.
.
.
.
.
.
.
.
.
.
.
1
.
1
.
1
.
1
.
1
...  
1
.
1
.
0
.
1
.
509  
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
1
510  
511  
FL1  
FASTLOCK  
0
1
NORMAL OPERATION  
FAST LOCK ENABLED  
Rev. A | Page 13 of 24  
 
ADF4153  
Table 8. R Divider Register Map  
CONTROL  
BITS  
MUXOUT  
4-BIT R COUNTER  
12-BIT INTERPOLATOR MODULUS VALUE (MOD)  
DB23 DB22 DB21  
DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8  
DB7 DB6 DB5 DB4 DB3 DB2  
DB1  
DB0  
DB20 DB19  
M1 P2  
M3  
M2  
P1  
R4  
R3  
R2  
R1  
M12  
M11  
M10  
M9  
M8  
M7  
M6  
M5  
M4  
M3  
M2  
M1  
P3  
C2 (0) C1 (1)  
P3 LOAD CONTROL  
P1  
PRESCALER  
INTERPOLATOR  
M12  
M11  
M10  
M3  
0
M2  
1
M1  
0
MODULUS VALUE (MOD)  
0
1
NORMAL OPERATION  
LOAD RESYNC  
0
1
4/5  
8/9  
0
0
0
..........  
2
0
0
.
.
.
0
0
.
.
.
0
0
.
.
.
..........  
..........  
..........  
..........  
..........  
..........  
0
1
.
.
.
1
0
.
.
.
1
0
.
.
.
3
4
.
.
.
1
1
1
1
0
0
4092  
1
1
1
1
1
1
1
1
1
..........  
..........  
..........  
1
1
1
0
1
1
1
0
1
4093  
4094  
4095  
RF R COUNTER  
DIVIDE RATIO  
R4  
R3  
R2  
R1  
0
0
0
0
.
0
0
0
1
.
0
1
1
0
.
1
0
1
0
.
1
2
3
4
.
.
.
.
.
.
.
.
.
.
.
1
1
0
0
12  
1
1
1
1
1
1
0
1
1
1
0
1
13  
14  
15  
M3  
M2  
M1  
MUXOUT  
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
THREE-STATE OUTPUT  
DIGITAL LOCK DETECT  
N DIVIDER OUTPUT  
LOGIC HIGH  
R DIVIDER OUTPUT  
ANALOG LOCK DETECT  
FASTLOCK SWITCH  
LOGIC LOW  
Rev. A | Page 14 of 24  
 
ADF4153  
Table 9. Control Register Map  
CP CURRENT  
SETTING  
CONTROL  
BITS  
RESYNC  
DB15 DB14 DB13 DB12 DB11 DB10 DB9  
S4 S3 S2 S1 U6 CP3 CP2  
DB8  
CP1  
DB7  
CP0  
DB6  
U5  
DB5  
U4  
DB4  
U3  
DB3 DB2  
U2 U1  
DB1  
DB0  
C2 (1) C1 (0)  
REFERENCE  
DOUBLER  
U6  
0
1
DISABLED  
ENABLED  
U1  
COUNTER RESET  
0
1
DISABLED  
ENABLED  
S4  
S3  
S2  
S1  
RESYNC  
0
0
0
.
0
0
0
.
0
1
1
.
1
0
1
.
1
2
3
U2  
CP THREE-STATE  
.
.
.
.
.
.
0
1
DISABLED  
THREE-STATE  
.
.
.
.
.
1
1
1
1
1
1
0
1
1
1
0
1
13  
14  
15  
U3  
POWER-DOWN  
0
1
NORMAL OPERATION  
POWER-DOWN  
I
(mA)  
CP  
CP3  
CP2  
CP1  
CP0  
2.7k  
5.1kΩ  
10kΩ  
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
1.09  
2.18  
3.26  
4.35  
5.44  
6.53  
7.62  
8.70  
0.63  
1.25  
1.88  
2.50  
3.13  
3.75  
4.38  
5.00  
0.29  
0.59  
0.88  
1.15  
1.47  
1.76  
2.06  
2.35  
U4  
LDP  
0
1
3
5
U5  
PD POLARITY  
0
1
NEGATIVE  
POSITIVE  
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0.54  
1.10  
1.64  
2.18  
2.73  
3.27  
3.81  
4.35  
0.31  
0.63  
0.94  
1.25  
1.57  
1.88  
2.19  
2.50  
0.15  
0.30  
0.44  
0.588  
0.74  
0.88  
1.03  
1.18  
Rev. A | Page 15 of 24  
 
ADF4153  
Table 10. Noise and Spur Register  
NOISE AND SPUR  
MODE  
CONTROL  
BITS  
RESERVED  
DB10  
T9  
DB9  
T8  
DB8  
T7  
DB7  
T6  
DB6  
T5  
DB5  
T4  
DB4  
T3  
DB3  
T2  
DB2  
T1  
DB1  
DB0  
C2 (1) C1 (1)  
DB10, DB5, DB4, DB3  
0
RESERVED  
RESERVED  
THESE BITS MUST BE SET TO 0  
FOR NORMAL OPERATION.  
DB9, DB8, DB7, DB6, DB2 NOISE AND SPUR SETTING  
00000  
11100  
11111  
LOWEST SPUR MODE  
LOW NOISE AND SPUR MODE  
LOWEST NOISE MODE  
Rev. A | Page 16 of 24  
 
ADF4153  
takes the clock from the RF input stage and divides it down for  
the counters. It is based on a synchronous 4/5 core. When set to  
4/5, the maximum RF frequency allowed is 2 GHz. Therefore,  
when operating the ADF4153 above 2 GHz, this must be set to  
8/9. The prescaler limits the INT value.  
N DIVIDER REGISTER, R0  
With R0[1, 0] set to [0, 0], the on-chip N divider register is  
programmed. Table 7 shows the input data format for  
programming this register.  
9-Bit INT Value  
With P = 4/5, NMIN = 31.  
With P = 8/9, NMIN = 91.  
These nine bits control what is loaded as the INT value. This is  
used to determine the overall feedback division factor. It is used  
in Equation 1.  
The prescaler can also influence the phase noise performance. If  
INT < 91, a prescaler of 4/5 should be used. For applications  
where INT > 91, P = 8/9 should be used for optimum noise  
performance (see Table 8).  
12-Bit FRAC Value  
These 12 bits control what is loaded as the FRAC value into the  
fractional interpolator. This is part of what determines the  
overall feedback division factor. It is used in Equation 1. The  
FRAC value must be less than or equal to the value loaded into  
the MOD register.  
4-Bit RF R Counter  
The 4-bit RF R counter allows the input reference frequency  
(REFIN) to be divided down to produce the reference clock to  
the phase frequency detector (PFD). Division ratios from 1 to  
15 are allowed.  
Fastlock  
When set to logic high, this enables the fastlock. This sets the  
charge pump current to its maximum value. When set to logic  
low, the charge pump current is equal to the value programmed  
in the function register.  
12-Bit Interpolator Modulus  
This programmable register sets the fractional modulus. This is  
the ratio of the PFD frequency to the channel step resolution on  
the RF output. Refer to the RF Synthesizer: A Worked Example  
section for more information.  
R DIVIDER REGISTER, R1  
With R1[1, 0] set to [0, 1], the on-chip R divider register is  
programmed. Table 8 shows the input data format for  
programming this register.  
The ADF4153 programmable modulus is double buffered. This  
means that two events have to occur before the part uses a new  
modulus value. First, the new modulus value is latched into the  
device by writing to the R divider register. Second, a new write  
must be performed on the N divider register. Therefore, any  
time that the modulus value has been updated, the N divider  
register must be written to after this, to ensure that the modulus  
value is loaded correctly.  
Load Control  
When set to logic high, the value being programmed in the  
modulus is not loaded into the modulus. Instead, it sets the  
resync delay of the Σ-Δ. This is done to ensure phase resync  
when changing frequencies. See the Phase Resync and Spur  
Consistency section for more information and a worked  
example.  
CONTROL REGISTER, R2  
MUXOUT  
With R2[1, 0] set to [0, 1], the on-chip control register is  
programmed. Table 9 shows the input data format for  
programming this register.  
The on-chip multiplexer is controlled by R1[22 ... 20] on the  
ADF4153. Table 8 shows the truth table.  
Digital Lock Detect  
RF Counter Reset  
The digital lock detect output goes high if there are 40  
successive PFD cycles with an input error of less than 15 ns. It  
stays high until a new channel is programmed or until the error  
at the PFD input exceeds 30 ns for one or more cycles. If the  
loop bandwidth is narrow compared to the PFD frequency, the  
error at the PFD inputs may drop below 15 ns for 40 cycles  
around a cycle slip. Therefore, the digital lock detect may go  
falsely high for a short period until the error again exceeds  
30 ns. In this case, the digital lock detect is reliable only as a  
loss-of-lock detector.  
DB3 is the RF counter reset bit for the ADF4153. When this is 1,  
the RF synthesizer counters are held in reset. For normal  
operation, this bit should be 0.  
RF Charge Pump Three-State  
This bit puts the charge pump into three-state mode when  
programmed to 1. It should be set to 0 for normal operation.  
RF Power-Down  
DB4 on the ADF4153 provides the programmable power-down  
mode. Setting this bit to 1 performs a power-down. Setting this  
bit to 0 returns the synthesizer to normal operation. While in  
software power-down mode, the part retains all information in  
its registers. Only when supplies are removed are the register  
contents lost.  
Prescaler (P/P + 1)  
The dual-modulus prescaler (P/P + 1), along with the INT,  
FRAC, and MOD counters, determines the overall division ratio  
from the RFIN to the PFD input. Operating at CML levels, it  
Rev. A | Page 17 of 24  
ADF4153  
When a power-down is activated, the following events occur:  
1. All active dc current paths are removed.  
dither is enabled. This randomizes the fractional quantization  
noise so that it looks more like white noise rather than spurious  
noise. This means that the part is optimized for improved  
spurious performance. This operation would normally be used  
when the PLL closed-loop bandwidth is wide, for fast-locking  
applications. (Wide-loop bandwidth is seen as a loop bandwidth  
greater than 1/10 of the RFOUT channel step resolution (fRES)). A  
wide-loop filter does not attenuate the spurs to a level that a  
narrow-loop bandwidth would. When the low noise and spur  
setting is enabled, dither is disabled. This optimizes the  
synthesizer to operate with improved noise performance.  
However, the spurious performance is degraded in this mode  
compared to the lowest spurs setting. To further improve noise  
performance, the lowest noise setting option can be used, which  
reduces the phase noise. As well as disabling the dither, it also  
ensures that the charge pump is operating in an optimum  
region for noise performance. This setting is extremely useful  
where a narrow-loop filter bandwidth is available. The  
synthesizer ensures extremely low noise and the filter attenuates  
the spurs. The typical performance characteristics give the user  
an idea of the trade-off in a typical WCDMA setup for the  
different noise and spur settings.  
2. The synthesizer counters are forced to their load state  
conditions.  
3. The charge pump is forced into three-state mode.  
4. The digital lock detect circuitry is reset.  
5. The RFIN input is debiased.  
6. The input register remains active and capable of loading  
and latching data.  
Lock Detect Precision (LDP)  
When this bit is programmed to 0, three consecutive reference  
cycles of 15 ns must occur before digital lock detect is set. When  
this bit is programmed to 1, five consecutive reference cycles of  
15 ns must occur before digital lock detect is set.  
Phase Detector Polarity  
DB6 in the ADF4153 sets the phase detector polarity. When the  
VCO characteristics are positive, this should be set to 1. When  
they are negative, it should be set to 0.  
Charge Pump Current Setting  
RESERVED BITS  
DB7, DB8, and DB9 set the charge pump current setting. This  
should be set to the charge pump current that the loop filter is  
designed with (see Table 9).  
These bits should be set to 0 for normal operation.  
RF SYNTHESIZER: A WORKED EXAMPLE  
This equation governs how the synthesizer should be  
programmed.  
REFIN Doubler  
Setting this bit to 0 feeds the REFIN signal directly to the 4-bit  
RF R counter, disabling the doubler. Setting this bit to 1  
multiplies the REFIN frequency by a factor of 2 before feeding  
into the 4-bit R counter. When the doubler is disabled, the REFIN  
falling edge is the active edge at the PFD input to the fractional  
synthesizer. When the doubler is enabled, both the rising and  
falling edges of REFIN become active edges at the PFD input.  
RFOUT  
where:  
=
[
INT +  
(
FRAC MOD  
)
]  
×
[
FPFD  
]
(3)  
RFOUT is the RF frequency output.  
INT is the integer division factor.  
FRAC is the fractionality.  
When the doubler is enabled and the lowest spur mode is  
chosen, the in-band phase noise performance is sensitive to the  
REFIN duty cycle. The phase noise degradation can be as much  
as 5 dB for the REFIN duty cycles outside a 45% to 55% range.  
The phase noise is insensitive to the REFIN duty cycle in the  
lowest noise mode and in the lowest noise and spur mode. The  
phase noise is insensitive to REFIN duty cycle when the doubler  
is disabled.  
MOD is the modulus.  
FPFD  
where:  
=
[
REFIN  
×
(
1 + D  
)
R
]
(4)  
REFIN is the reference frequency input.  
D is the RF REFIN doubler bit.  
NOISE AND SPUR REGISTER, R3  
With R3[1, 0] set to 1, 1, the on-chip noise and spur register is  
programmed. Table 10 shows the input data format for  
programming this register.  
R is the RF reference division factor.  
Noise and Spur Mode  
Noise and spur mode allows the user to optimize a design either  
for improved spurious performance or for improved phase  
noise performance. When the lowest spur setting is chosen,  
Rev. A | Page 18 of 24  
ADF4153  
Example: In a GSM 1800 system, where 1.8 GHz RF frequency  
output (RFOUT) is required, a 13 MHz reference frequency input  
(REFIN) is available and a 200 kHz channel resolution (fRES) is  
required on the RF output.  
benefit. PDC requires 25 kHz channel step resolution, whereas  
GSM 1800 requires 200 kHz channel step resolution. A 13 MHz  
reference signal could be fed directly to the PFD. The modulus  
would be programmed to 520 when in PDC mode (13 MHz/  
520 = 25 kHz). The modulus would be reprogrammed to 65 for  
GSM 1800 operation (13 MHz/65 = 200 kHz). It is important  
that the PFD frequency remains constant (13 MHz). This allows  
the user to design one loop filter that can be used in both setups  
without running into stability issues. It is the ratio of the RF  
frequency to the PFD frequency that affects the loop design.  
Keeping this relationship constant, instead of changing the  
modulus factor, results in a stable filter.  
MOD = REFIN fRES  
MOD =13 MHz 200 kHz = 65  
From Equation 4:  
FPFD  
=
[
13 MHz ×  
(
1 + 0  
)
1
]
=13 MHz  
(5)  
(6)  
1.8 G =13 MHz ×  
(
INT + FRAC 65 ≥  
)
INT =138; FRAC = 30  
SPURIOUS OPTIMIZATION AND FASTLOCK  
As mentioned earlier, the part can be optimized for spurious  
performance. However, in fast locking applications, the loop  
bandwidth needs to be wide, and therefore the filter does not  
provide much attenuation of the spurs. The programmable  
charge pump can be used to get around this issue. The filter is  
designed for a narrow-loop bandwidth so that steady-state  
spurious specifications are met. This is designed using the  
lowest charge pump current setting. To implement fastlock  
during a frequency jump, the charge pump current is set to the  
maximum setting for the duration of the jump. This has the  
effect of widening the loop bandwidth, which improves lock  
time. When the PLL has locked to the new frequency, the charge  
pump is again programmed to the lowest charge pump current  
setting. This narrows the loop bandwidth to its original cutoff  
frequency to allow better attenuation of the spurs than the  
wide-loop bandwidth.  
MODULUS  
The choice of modulus (MOD) depends on the reference signal  
(REFIN) available and the channel resolution (fRES) required at  
the RF output. For example, a GSM system with 13 MHz REFIN  
would set the modulus to 65. This means that the RF output  
resolution (fRES) is the 200 kHz (13 MHz/65) necessary for GSM.  
REFERENCE DOUBLER AND REFERENCE DIVIDER  
The reference doubler on-chip allows the input reference signal  
to be doubled. This is useful for increasing the PFD comparison  
frequency. Making the PFD frequency higher improves the  
noise performance of the system. Doubling the PFD frequency  
usually results in an improvement in noise performance of 3 dB.  
It is important to note that the PFD cannot be operated above  
32 MHz due to a limitation in the speed of the Σ-Δ circuit of  
the N divider.  
PHASE RESYNC AND SPUR CONSISTENCY  
12-BIT PROGRAMMABLE MODULUS  
Setting the RESYNC bits [S4 ,S3, S2, and S1] enables the phase  
RESYNC feature. With a fractional denominator of MOD, a  
fractional-N PLL can settle with any one of (2 × π)/MOD valid  
phase offsets with respect to the reference input. This is  
different from integer-N where the RF output always settles to  
the same static phase offset with respect to the input reference,  
which is zero ideally. This is not an issue in applications that  
require only a consistent frequency lock. When RESYNC is  
enabled, it also ensures that spur levels remain consistent when  
the PLL returns to a certain frequency. This is due to the fact  
that the RESYNC function resets the Σ-Δ modulator. RESYNC  
is enabled by setting the S4 to S1 bits in R2 to a nonzero value.  
When the S4 to S1 bits are 0, 0, 0, and 0, RESYNC is disabled.  
Unlike most other fractional-N PLLs, the ADF4153 allows the  
user to program the modulus over a 12-bit range. This means  
that the user can set up the part in many different  
configurations for the application, when combined with the  
reference doubler and the 4-bit R counter.  
For example, here is an application that requires 1.75 GHz RF  
and 200 kHz channel step resolution. The system has a 13 MHz  
reference signal.  
One possible setup is feeding the 13 MHz directly to the PFD  
and programming the modulus to divide by 65. This would  
result in the required 200 kHz resolution.  
For applications where a consistent phase relationship between  
the output and reference is required (i.e., digital beam forming),  
the ADF4153 can be used with the phase resync feature enabled.  
This ensures that if the user programs the PLL to jump from  
Frequency (and Phase) A to Frequency (and Phase) B and back  
again to Frequency A, the PLL returns to the original phase  
(Phase A).  
Another possible setup is using the reference doubler to create  
26 MHz from the 13 MHz input signal. This 26 MHz is then fed  
into the PFD. The modulus is now programmed to divide by  
130. This also results in 200 kHz resolution and offers superior  
phase noise performance over the previous setup.  
The programmable modulus is also very useful for multi-  
standard applications. If a dual-mode phone requires PDC and  
GSM 1800 standards, the programmable modulus is a huge  
Rev. A | Page 19 of 24  
ADF4153  
When enabled, it activates every time the user programs  
Register R0 to set a new output frequency. However, if a cycle  
slip occurs in the settling transient after the phase RESYNC  
operation, the phase RESYNC is lost. This can be avoided by  
delaying the RESYNC activation until the locking transient is  
close to its final frequency. This is done by rewriting to R1 after  
R1 has been set up as normal. Setting load control [DB23]  
allows this. When set, instead of determining the fractional  
denominator, the MOD bits [M12 to M1] are used to set a time  
interval from when the new channel is programmed to the time  
the RESYNC is activated. This is called the delay. Its value  
should be programmed to set a time interval that is at least as  
long as the RF PLL lock time.  
INTERFACING  
The ADF4153 has a simple SPI® compatible serial interface for  
writing to the device. SCLK, SDATA, and LE control the data  
transfer. When LE (latch enable) is high, the 22 bits that have  
been clocked into the input register on each rising edge of  
SCLK 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 for the device is  
909 kHz or one update every 1.1 µs. This is more than adequate  
for systems that have typical lock times in the hundreds of  
microseconds.  
ADuC812 Interface  
For example, if REFIN = 26 MHz and MOD = 130 to give  
200 kHz output steps (fRES), and the RF loop has a settling  
time of 150 µs, then delay should be programmed to 3,900,  
as 26 MHz × 150 µs = 3,900.  
Figure 21 shows the interface between the ADF4153 and the  
ADuC812 MicroConverter®. Since 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 ADF4153 needs a  
24-bit word, which is accomplished by writing three 8-bit bytes  
from the MicroConverter to the device. After the third byte is  
written, the LE input should be brought high to complete the  
transfer.  
If the application requires the delay to be greater than 4095, the  
RESYNC bits should be increased. For example, if the lock time  
above is 1.5 ms, the delay should be programmed to 26 MHz ×  
1.5 ms = 39,000. In this case, program M12 to M1 to 3,900 and  
program S4 to S1 to 10. The delay is 3,900 × 10 = 39,000.  
SPURIOUS SIGNALS—PREDICTING WHERE THEY  
WILL APPEAR  
When operating in the mode described, 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  
180 kHz.  
Just as in integer-N PLLs, spurs appear at PFD frequency offsets  
from the carrier. In a fractional-N PLL, spurs also appear at  
frequencies equal to the RFOUT channel step resolution (fRES).  
The third-order fractional interpolator engine of the ADF4153  
may also introduce subfractional spurs. If the fractional  
denominator (MOD) is divisible by 2, spurs appear at 1/2 fRES. If  
the fractional denominator (MOD) is divisible by 3, spurs  
appear at 1/3 fRES. Harmonics of all spurs mentioned will also  
appear. With the lowest spur mode enabled, the fractional and  
subfractional spurs is attenuated dramatically. The worst-case  
spurs appear when the fraction is programmed to (1/MOD).  
For example, in a GSM 900 MHz system with a 26 MHz PFD  
frequency and an RFOUT channel step resolution (fRES) of 200  
kHz, the MOD = 130. PFD spurs appear at 26 MHz offset, and  
fractional spurs appear at 200 kHz offset. Since MOD is  
divisible by 2, subfractional spurs are also present at 100 kHz  
offset.  
ADuC812  
ADF4153  
SCLOCK  
SCLK  
MOSI  
SDATA  
LE  
I/O PORTS  
MUXOUT  
(LOCK DETECT)  
Figure 21. ADuC812 to ADF4153 Interface  
FILTER DESIGN—ADISIMPLL  
A filter design and analysis program is available to help the user  
to implement PLL design. Visit www.analog.com/pll for a free  
download of the ADIsimPLL software. The software designs,  
simulates, and analyzes the entire PLL frequency domain and  
time domain response. Various passive and active filter  
architectures are allowed. REV. #2 of ADIsimPLL allows analysis  
of the ADF4153.  
Rev. A | Page 20 of 24  
 
ADF4153  
ADSP-2181 Interface  
PCB DESIGN GUIDELINES FOR CHIP SCALE  
PACKAGE  
Figure 22 shows the interface between the ADF4153 and the  
ADSP-21xx digital signal processor. As discussed previously, the  
ADF4153 needs a 24-bit serial word for each latch write. The  
easiest way 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. Set up the word  
length for eight bits and use three memory locations for each  
24-bit word. To program each 24-bit latch, store the three 8-bit  
bytes, enable the autobuffered mode, and write to the transmit  
register of the DSP. This last operation initiates the autobuffer  
transfer.  
The lands on the chip scale package (CP-20) are rectangular.  
The printed circuit board pad for these should be 0.1 mm  
longer than the package land length and 0.05 mm wider than  
the package land width. The land should be centered on the pad.  
This ensures 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. This ensures 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 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 oz. copper  
to plug the via.  
ADSP-21xx  
ADF4153  
SCLK  
SCLOCK  
SDATA  
LE  
DT  
TFS  
The user should connect the printed circuit board thermal pad  
to AGND.  
MUXOUT  
(LOCK DETECT)  
I/O FLAGS  
Figure 22. ADSP-21xx to ADF4153 Interface  
Rev. A | Page 21 of 24  
 
ADF4153  
OUTLINE DIMENSIONS  
5.10  
5.00  
4.90  
16  
9
8
4.50  
4.40  
4.30  
6.40  
BSC  
1
PIN 1  
1.20 MAX  
0.15  
0.05  
0.20  
0.09  
0.75  
0.60  
0.45  
8°  
0°  
0.30  
0.19  
0.65  
BSC  
SEATING  
PLANE  
COPLANARITY  
0.10  
COMPLIANT TO JEDEC STANDARDS MO-153AB  
Figure 23. 16-Lead Thin Shrink Small Outline Package [TSSOP]  
(RU-16)  
Dimensions shown in millimeters  
0.60  
MAX  
4.0  
BSC SQ  
0.60  
MAX  
16  
15  
20  
1
PIN 1  
INDICATOR  
2.25  
2.10 SQ  
1.95  
3.75  
BSC SQ  
TOP  
VIEW  
BOTTOM  
VIEW  
11  
10  
5
0.75  
0.55  
0.35  
6
0.25 MIN  
0.80 MAX  
0.65 TYP  
0.30  
0.23  
0.18  
12° MAX  
1.00  
0.85  
0.80  
0.05 MAX  
0.02 NOM  
0.20  
REF  
COPLANARITY  
0.08  
SEATING  
PLANE  
0.50  
BSC  
COMPLIANT TO JEDEC STANDARDS MO-220-VGGD-1  
Figure 24. 20-Lead Lead Frame Chip Scale Package [LFCSP]  
4 mm × 4 mm Body  
(CP-20)  
Dimensions shown in millimeters  
ORDERING GUIDE  
Model  
ADF4153BRU  
ADF4153BRU-REEL  
ADF4153BRU-REEL7  
ADF4153BCP  
ADF4153BCP-REEL  
ADF4153BCP-REEL7  
EVAL-ADF4153EB1  
Description  
Temperature Range  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
Package Option  
RU-16  
RU-16  
RU-16  
CP-20  
Thin Shrink Small Outline Package (TSSOP)  
Thin Shrink Small Outline Package (TSSOP)  
Thin Shrink Small Outline Package (TSSOP)  
Lead Frame Chip Scale Package (LFCSP)  
Lead Frame Chip Scale Package (LFCSP)  
Lead Frame Chip Scale Package (LFCSP)  
Evaluation Board  
CP-20  
CP-20  
Rev. A | Page 22 of 24  
ADF4153  
NOTES  
Rev. A | Page 23 of 24  
ADF4153  
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.  
C03685–0–1/04(A)  
Rev. A | Page 24 of 24  

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