PLL Frequency Synthesizer ADF4107 FEATURES GENERAL DESCRIPTION 7.0 GHz bandwidth 2.7 V to 3.3 V power supply Separate charge pump supply (VP) allows extended tuning voltage in 3 V systems Programmable dual-modulus prescaler 8/9, 16/17, 32/33, 64/65 Programmable charge pump currents Programmable antibacklash pulsewidth 3-wire serial interface Analog and digital lock detect Hardware and software power-down mode The ADF4107 frequency synthesizer can be used to implement local oscillators in the up-conversion and down-conversion sections of wireless receivers and transmitters. It consists of a low-noise digital PFD (phase frequency detector), a precision charge pump, a programmable reference divider, programmable A and B counters, and a dual-modulus prescaler (P/P + 1). The A (6-bit) and B (13-bit) counters, in conjunction with the dualmodulus prescaler (P/P + 1), implement an N divider (N = BP + A). In addition, the 14-bit reference counter (R counter), allows selectable REFIN frequencies at the PFD input. A complete PLL (phase-locked loop) can be implemented if the synthesizer is used with an external loop filter and VCO (voltage controlled oscillator). Its very high bandwidth means that frequency doublers can be eliminated in many high frequency systems, simplifying system architecture and reducing cost. APPLICATIONS Broadband wireless access Satellite systems Instrumentation Wireless LANs Base stations for wireless radio FUNCTIONAL BLOCK DIAGRAM AVDD DVDD VP RSET CPGND REFERENCE 14-BIT R COUNTER REFIN PHASE FREQUENCY DETECTOR CHARGE PUMP CP 14 R COUNTER LATCH CLK DATA LE 24-BIT INPUT REGISTER FUNCTION LATCH 22 FROM SDOUT FUNCTION LATCH A, B COUNTER LATCH CURRENT SETTING 1 CURRENT SETTING 2 CPI3 CPI2 CPI1 CPI6 CPI5 CPI4 HIGH Z 19 AVDD MUXOUT MUX 13 N = BP + A RFINA RFINB LOCK DETECT 13-BIT B COUNTER SDOUT LOAD PRESCALER P/P + 1 LOAD M3 M2 M1 6-BIT A COUNTER ADF4107 6 CE AGND DGND Figure 1. Rev. 0 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 companies. 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 © 2003 Analog Devices, Inc. All rights reserved. ADF4107 TABLE OF CONTENTS ADF4107—Specifications................................................................ 3 Latch Summary........................................................................... 11 Timing Characteristics..................................................................... 5 Reference Counter Latch Map.................................................. 12 Absolute Maximum Ratings............................................................ 5 AB Counter Latch Map ............................................................. 13 Pin Configurations and Functional Descriptions ........................ 6 Function Latch Map................................................................... 14 Typical Performance Characteristics ............................................. 7 Initialization Latch Map ............................................................ 15 Functional Description .................................................................... 9 Function Latch............................................................................ 16 Reference Input Stage................................................................... 9 Initialization Latch ..................................................................... 17 RF Input Stage............................................................................... 9 Applications..................................................................................... 18 Prescaler (P/P + 1)........................................................................ 9 Local Oscillator for LMDS Base Station Transmitter............ 18 A and B Counters ......................................................................... 9 Interfacing ................................................................................... 19 R Counter ...................................................................................... 9 PCB Design Guidelines for Chip Scale Package .................... 19 Phase Frequency Detector and Charge Pump........................ 10 Outline Dimensions ....................................................................... 20 MUXOUT and Lock Detect...................................................... 10 ESD Caution.................................................................................... 20 Input Shift Register..................................................................... 10 Ordering Guide............................................................................... 20 REVISION HISTORY Revision 0: Initial Version Rev. 0 | Page 2 of 20 ADF4107 ADF4107—SPECIFICATIONS Table 1. (AVDD = DVDD = 3 V ± 10%, AVDD ≤ VP ≤ 5.5 V, AGND = DGND = CPGND = 0 V, RSET = 5.1 kΩ, dBm referred to 50 Ω, TA = TMAX to TMIN, unless otherwise noted.) B Version1 B Chips2 (Typ) Unit Test Conditions/Comments 1.0/7.0 –5/+5 300 1.0/7.0 –5/+5 300 GHz min/max dBm min/max MHz max See Figure 18 for input circuit. 20/250 0.8/VDD 20/250 0.8/VDD MHz min/max V p-p min/max For f < 20 MHz, use dc-coupled square wave (0 to VDD). AC-coupled; when dc-coupled, 0 to VDD, max (CMOS compatible). REFIN Input Capacitance REFIN Input Current PHASE DETECTOR Phase Detector Frequency6 CHARGE PUMP ICP Sink/Source High Value Low Value Absolute Accuracy RSET Range ICP Three-State Leakage Sink and Source Current Matching 10 ±100 10 ±100 pF max µA max 104 104 MHz max 5 625 2.5 3.0/11 1 2 5 625 2.5 3.0/11 1 2 mA typ µA typ % typ kΩ typ nA typ % typ 0.5 V ≤ VCP ≤ VP – 0.5 V ICP vs. VCP ICP vs. Temperature LOGIC INPUTS VIH, Input High Voltage VIL, Input Low Voltage IINH, IINL, Input Current CIN, Input Capacitance LOGIC OUTPUTS VOH, Output High Voltage VOH, Output High Voltage IOH VOL, Output Low Voltage POWER SUPPLIES AVDD DVDD VP IDD7 (AIDD + DIDD) IP Power-Down Mode8 (AIDD + DIDD) 1.5 2 1.5 2 % typ % typ 0.5 V ≤ VCP ≤ VP – 0.5 V VCP = VP/2 1.4 0.6 ±1 10 1.4 0.6 ±1 10 V min V max µA max pF max 1.4 VDD – 0.4 100 0.4 1.4 VDD – 0.4 100 0.4 V min V min µA max V max 2.7/3.3 AVDD AVDD/5.5 17 0.4 10 2.7/3.3 AVDD AVDD/5.5 15 0.4 10 V min/V max Parameter RF CHARACTERISTICS RF Input Frequency (RFIN)3 RF Input Sensitivity Maximum Allowable Prescaler Output Frequency4 REFIN CHARACTERISTICS REFIN Input Frequency REFIN Input Sensitivity5 Programmable; see Figure 25. V min/V max mA max mA max µA typ Rev. 0 | Page 3 of 20 With RSET = 5.1 kΩ With RSET = 5.1 kΩ See Figure 25. Open-drain output chosen; 1 kΩ pull-up resistor to 1.8 V. CMOS output chosen. IOL = 500 µA AVDD ≤ VP ≤5.5V 15 mA typ TA = 25°C ADF4107 Parameter NOISE CHARACTERISTICS ADF4107 Phase Noise Floor9 Phase Noise Performance10 900 MHz Output11 6400 MHz Output12 6400 MHz Output13 Spurious Signals 900 MHz Output11 6400 MHz Output12 6400 MHz Output13 B Version1 B Chips2 (Typ) Unit Test Conditions/Comments –174 –166 –159 –174 –166 –159 dBc/Hz typ dBc/Hz typ dBc/Hz typ –93 –76 –83 –93 –76 –83 dBc/Hz typ dBc/Hz typ dBc/Hz typ @ 25 kHz PFD Frequency @ 200 kHz PFD Frequency @ 1 MHz PFD Frequency @ VCO Output @ 1 kHz offset and 200 kHz PFD Frequency @ 1 kHz offset and 200 kHz PFD Frequency @ 1 kHz offset and 1 MHz PFD Frequency –90/–92 –65/–70 –70/–75 –90/–92 –65/–70 –70/–75 dBc typ dBc typ dBc typ @ 200 kHz/400kHz and 200 kHz PFD Frequency @ 200 kHz/400kHz and 200 kHz PFD Frequency @ 1 MHz/2MHz and 1 MHz PFD Frequency 1 Operating temperature range (B Version) is –40°C to +85°C. The B Chip specifications are given as typical values. 3 Use a square wave for lower frequencies, below the minimum stated. 4 This is the maximum operating frequency of the CMOS counters. The prescaler value should be chosen to ensure that the RF input is divided down to a frequency that is less than this value. 5 AVDD = DVDD = 3 V. 6 Guaranteed by design. Sample tested to ensure compliance. 7 TA = 25°C; AVDD = DVDD = 3 V; P = 32; RFIN = 7.0 GHz. 8 TA = 25°C; AVDD = DVDD = 3.3 V; R = 16383; A = 63; B = 891; P = 32; RFIN = 7.0 GHz. 9 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). 10 The phase noise is measured with the EVAL-ADF4107EB1 Evaluation Board and the HP8562E Spectrum Analyzer. The spectrum analyzer provides the REFIN for the synthesizer (fREFOUT = 10 MHz @ 0 dBm). 11 fREFIN = 10 MHz; fPFD = 200 kHz; Offset Frequency = 1 kHz; fRF = 900 MHz; N = 4500; Loop B/W = 20 kHz. 12 fREFIN = 10 MHz; fPFD = 200 kHz; Offset Frequency = 1 kHz; fRF = 6400 MHz; N = 32000; Loop B/W = 20 kHz. 13 fREFIN = 10 MHz; fPFD = 1 MHz; Offset Frequency = 1 kHz; fRF = 6400 MHz; N = 6400; Loop B/W = 100 kHz. 2 Rev. 0 | Page 4 of 20 ADF4107 TIMING CHARACTERISTICS Table 2. (AVDD = DVDD = 3 V ± 10%, AVDD ≤ VP ≤ 5.5 V, AGND = DGND = CPGND = 0 V, RSET = 5.1 kΩ, dBm referred to 50 Ω, TA = TMAX to TMIN, unless otherwise noted.) 1 Limit2 (B Version) 10 10 25 25 10 20 Parameter t1 t2 t3 t4 t5 t6 1 2 Unit ns min ns min ns min ns min ns min ns min Test Conditions/Comments DATA to CLOCK Setup Time DATA to CLOCK Hold Time CLOCK High Duration CLOCK Low Duration CLOCK to LE Setup Time LE Pulsewidth Guaranteed by design but not production tested. Operating temperature range (B Version) is –40°C to +85°C. t3 t4 CLOCK t1 DATA DB23 (MSB) t2 DB1 (CONTROL BIT C2) DB2 DB22 DB0 (LSB) (CONTROL BIT C1) t6 LE t5 LE Figure 2. Timing Diagram ABSOLUTE MAXIMUM RATINGS Table 3. (TA = 25°C, unless otherwise noted.) Parameter AVDD to GND1 AVDD to DVDD VP to GND VP to AVDD Digital I/O Voltage to GND Analog I/O Voltage to GND REFIN, RFINA, RFINB to GND Operating Temperature Range Industrial (B Version) Storage Temperature Range Maximum Junction Temperature TSSOP θJA Thermal Impedance CSP θJA Thermal Impedance Lead Temperature, Soldering Vapor Phase (60 sec) Infrared (15 sec) Transistor Count CMOS Bipolar Rating –0.3 V to +3.6 V –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 VP + 0.3 V –0.3 V to VDD + 0.3 V –40°C to +85°C –65°C to +125°C 150°C 150.4°C/W 122°C/W 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. 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. 215°C 220°C 6425 303 1 GND = AGND = DGND = 0 V. Rev. 0 | Page 5 of 20 ADF4107 PIN CONFIGURATIONS AND FUNCTIONAL DESCRIPTIONS CSP (Chip Scale Package) RSET 1 16 VP CP 2 15 DVDD CPGND 3 14 MUXOUT ADF4107 20 CP 19 RSET 18 VP 17 DVDD 16 DVDD TSSOP 13 LE TOP VIEW RFINB 5 (Not to Scale) 12 DATA RFINA 6 11 CLK AVDD 7 10 CE REFIN 8 9 DGND CPGND 1 AGND 2 AGND 3 RFINB 4 RFINA 5 PIN 1 INDICATOR ADF4107 TOP VIEW 15 MUXOUT 14 LE 13 DATA 12 CLK 11 CE AVDD 6 AVDD 7 REFIN 8 DGND 9 DGND 10 AGND 4 Figure 3. ADF4107 TSSOP (Top View) Figure 4. ADF4107 Chip Scale Package Table 4. Pin Functional Descriptions Mnemonic RSET Function Connecting a resistor between this pin and CPGND sets the maximum charge pump output current. The nominal voltage potential at the RSET pin is 0.66 V. The relationship between ICP and RSET is 25.5 I CP MAX = R SET CP CPGND AGND RFINB RFINA AVDD REFIN DGND CE CLK DATA LE MUXOUT DVDD VP so, with RSET = 5.1 kΩ, ICP MAX = 5 mA. Charge Pump Output. When enabled, this pin provides ±ICP to the external loop filter, which in turn drives the external VCO. 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 must be decoupled to the ground plane with a small bypass capacitor, typically 100 pF. See Figure 18. Input to the RF Prescaler. This small signal input is ac-coupled to the external VCO. Analog Power Supply. This voltage may range from 2.7 V to 3.3 V. Decoupling capacitors to the analog ground plane should be placed as close as possible to this pin. AVDD must be the same value as DVDD. Reference Input. This is a CMOS input with a nominal threshold of VDD/2 and a dc equivalent input resistance of 100 kΩ. See Figure 17. This input can be driven from a TTL or CMOS crystal oscillator or it can be ac-coupled. Digital Ground. Chip Enable. A logic low on this pin powers down the device and puts the charge pump output into three-state mode. Taking the pin high will power up the device, depending on the status of the power-down bit, F2. 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. 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 goes 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 lock detect, the scaled RF, or the scaled reference frequency to be accessed externally. Digital Power Supply. This may range from 2.7 V to 3.3 V. Decoupling capacitors to the digital ground plane should be placed as close as possible to this pin. DVDD must be the same value as AVDD. Charge Pump Power Supply. This voltage should be greater than or equal to VDD. In systems where VDD is 3 V, it can be set to 5 V and used to drive a VCO with a tuning range of up to 5 V. Rev. 0 | Page 6 of 20 ADF4107 TYPICAL PERFORMANCE CHARACTERISTICS –40 10dB/DIV RL = –40dBc/Hz RMS NOISE = 0.36o –50 PHASE NOISE – dBc/Hz –60 –70 –80 –90 –100 –110 –120 –130 –140 100Hz 1MHz FREQUENCY OFFSET FROM 900MHz CARRIER Figure 5. Parameter Data for the RF Input Figure 8. Integrated Phase Noise (900 MHz, 200 kHz, 20 kHz) 0 0 –5 –10 –20 OUTPUT POWER – dB RF INPUT POWER – dBm REF LEVEL = –14.0dBm VDD = 3V VP = 3V –10 –15 o TA = +85 C –20 TA = +25oC –50 –60 –70 –91.0dBc/Hz –90 TA = –40oC 0 1 2 3 4 5 RF INPUT FREQUENCY – GHz 6 –100 7 Figure 6. Input Sensitivity –400kHz –200kHz 900MHz +200kHz FREQUENCY +400kHz Figure 9. Reference Spurs (900 MHz, 200 kHz, 20 kHz) 0 0 –10 –20 –30 –40 REF LEVEL = –10dBm VDD = 3V, VP = 5V ICP = 5mA PFD FREQUENCY = 200kHz LOOP BANDWIDTH = 20kHz RES BANDWIDTH = 10Hz VIDEO BANDWIDTH = 10Hz SWEEP = 1.9 SECONDS AVERAGES = 10 –10 –20 OUTPUT POWER – dB REF LEVEL = –14.3dBm OUTPUT POWER – dB –40 –80 –25 –30 –30 VDD = 3V, VP = 5V ICP = 5mA PFD FREQUENCY = 200kHz LOOP BANDWIDTH = 20kHz RES BANDWIDTH = 1kHz VIDEO BANDWIDTH = 1kHz SWEEP = 2.5 SECONDS AVERAGES = 30 –50 –60 –93.0dBc/Hz –70 –30 –40 VDD = 3V, VP = 5V ICP = 5mA PFD FREQUENCY = 1MHz LOOP BANDWIDTH = 100kHz RES BANDWIDTH = 10Hz VIDEO BANDWIDTH = 10Hz SWEEP = 1.9 SECONDS AVERAGES = 10 –50 –60 –70 –80 –80 –90 –90 –100 –100 –2kHz –1kHz 900MHz FREQUENCY +1kHz +2kHz –83.0dBc/Hz –2kHz –1kHz 6400MHz FREQUENCY +1kHz Figure 10. Phase Noise (6.4 GHz, 1 MHz, 100 kHz) Figure 7. Phase Noise (900 MHz, 200 kHz, 20 kHz) Rev. 0 | Page 7 of 20 +2kHz ADF4107 –40 –5 10dB/DIV RL = –40dBc/Hz RMS NOISE = 1.85o –50 –25 FIRST REFERENCE SPUR – dBc PHASE NOISE – dBc/Hz –60 –70 –80 –90 –100 –110 –120 –35 –45 –55 –65 –75 –85 –95 –130 –140 100Hz –105 1MHz FREQUENCY OFFSET FROM 6400MHz CARRIER Figure 11. Integrated Phase Noise (6.4 GHz, 1 MHz, 100 kHz) 1 2 3 TUNING VOLTAGE – V 4 –120 –20 –30 –40 VDD = 3V, VP = 5V ICP = 5mA PFD FREQUENCY = 1MHz LOOP BANDWIDTH = 100kHz RES BANDWIDTH = 1kHz VIDEO BANDWIDTH = 1kHz SWEEP = 13 SECONDS AVERAGES = 1 –50 –65.0dBc/Hz –66.0dBc/Hz 5 VDD = 3V VP = 5V –130 PHASE NOISE – dBc/Hz REF LEVEL = –10dBm –60 0 Figure 14. Reference Spurs vs. VTUNE (6.4 GHz, 1 MHz, 100 kHz) 0 –10 OUTPUT POWER – dB VDD = 3V VP = 5V –15 –70 –80 –140 –150 –160 –170 –90 –100 –2MHz –1MHz 6400MHz FREQUENCY +1MHz –180 10k +2MHz Figure 12. Reference Spurs (6.4 GHz, 1 MHz, 100 kHz) 100M Figure 15. Phase Noise (referred to CP output) vs. PFD Frequency –60 6 VDD = 3V VP = 3V 5 4 VP = 5V ICP SETTLING = 5mA 3 –70 2 ICP – mA PHASE NOISE – dBc/Hz 100k 1M 10M PHASE DETECTOR FREQUENCY – Hz –80 1 0 –1 –2 –3 –90 –4 –5 –100 –40 –6 –20 0 20 40 60 o TEMPERATURE – C 80 0 100 0.5 1.0 1.5 2.0 2.5 3.0 VCP – V 3.5 4.0 Figure 16. Charge Pump Output Characteristics Figure 13. Phase Noise (6.4 GHz, 1 MHz, 100 kHz) vs. Temperature Rev. 0 | Page 8 of 20 4.5 5.0 ADF4107 FUNCTIONAL DESCRIPTION Reference Input Stage The Reference Input stage is shown in Figure 17. 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. POWER-DOWN CONTROL NC 100kΩ SW2 REFIN TO R COUNTER NC SW1 BUFFER NO synchronous 4/5 core. A minimum divide ratio is possible for fully contiguous output frequencies. This minimum is determined by P, the prescaler value, and is given by: (P2 – P). A and B Counters The A and B CMOS counters combine with the dual-modulus prescaler to allow a wide ranging division ratio in the PLL feedback counter. The counters are specified to work when the prescaler output is 300 MHz or less. Thus, with an RF input frequency of 4.0 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 equation for the VCO frequency is as follows: SW3 Figure 17. Reference Input Stage fVCO = [(P × B ) + A ]× RF Input Stage The RF input stage is shown in Figure 18. It is followed by a 2-stage limiting amplifier to generate the CML clock levels needed for the prescaler. BIAS GENERATOR 500Ω 1.6V fVCO Output frequency of external voltage controlled oscillator (VCO). P Preset modulus of dual-modulus prescaler (8/9, 16/17, etc.). B Preset divide ratio of binary 13-bit counter (3 to 8191). A Preset divide ratio of binary 6-bit swallow counter (0 to 63). AVDD 500Ω f REFIN R fREFIN External reference frequency oscillator. RFINA N = BP + A RFINB 13-BIT B COUNTER FROM RF INPUT STAGE PRESCALER P/P + 1 AGND MODULUS CONTROL Figure 18. RF Input Stage TO PFD LOAD LOAD 6-BIT A COUNTER N DIVIDER Prescaler (P/P + 1) Figure 19. A and B Counters 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 RF input stage 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, 32/33, or 64/65. It is based on a 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. Rev. 0 | Page 9 of 20 ADF4107 Phase Frequency Detector and Charge Pump The phase frequency detector (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 20 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 reference counter latch, ABP2 and ABP1, control the width of the pulse. See Figure 23. VP HI D1 Q1 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, this output will be high with narrow, low-going pulses. DVDD ANALOG LOCK DETECT DIGITAL LOCK DETECT R COUNTER OUTPUT CONTROL MUXOUT SDOUT CHARGE PUMP UP DGND U1 R DIVIDER MUX N COUNTER OUTPUT Figure 21. MUXOUT Circuit CLR1 PROGRAMMABLE DELAY ABP2 HI U3 CP ABP1 CLR2 DOWN D2 Q2 U2 N DIVIDER CPGND Figure 20. PFD Simplified Schematic and Timing (in Lock) MUXOUT and Lock Detect The output multiplexer on the ADF4107 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. Figure 25 shows the full truth table. Figure 21 shows the MUXOUT section in block diagram form. Lock Detect MUXOUT can be programmed for two types of lock detect: digital lock detect and analog lock detect. Input Shift Register The ADF4107 digital section includes a 24-bit input shift register, a 14-bit R counter, and a 19-bit N counter, comprising a 6-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 the timing diagram of Figure 2. The truth table for these bits is shown in Table 5. Figure 22 shows a summary of how the latches are programmed. Table 5. C2, C1 Truth Table Control Bits C2 C1 0 0 0 1 1 0 1 1 Digital lock detect is active high. When the lock detect precision (LDP) bit in the R counter latch is set to 0, digital lock detect is set high when the phase error on three consecutive phase detector (PD) cycles is less than 15 ns. With LDP set to 1, five consecutive cycles of less than 15 ns are required to set the lock detect. It will stay set high until a phase error of greater than 25 ns is detected on any subsequent PD cycle. Rev. 0 | Page 10 of 20 Data Latch R Counter N Counter (A and B) Function Latch (Including Prescaler) Initialization Latch ADF4107 Latch Summary LOCK DETECT PRECISION REFERENCE COUNTER LATCH RESERVED TEST MODE BITS ANTIBACKLASH WIDTH DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 X 0 0 LDP T2 T1 CONTROL BITS 14-BIT REFERENCE COUNTER ABP2 ABP1 R14 R13 R12 R11 R10 R9 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 R8 R7 R6 R5 R4 R3 R2 R1 DB1 DB0 C2 (0) C1 (0) RESERVED CP GAIN N COUNTER LATCH 13-BIT B COUNTER DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 X X G1 B13 B12 B11 B10 B9 B8 B7 B6 CONTROL BITS 6-BIT A COUNTER B5 B4 B3 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 B2 B1 A6 A5 A4 A3 A2 A1 C2 (0) C1 (1) CONTROL BITS DB1 DB0 FASTLOCK ENABLE CP THREESTATE PD POLARITY POWERDOWN 1 COUNTER RESET DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 F4 F3 F2 M3 M2 M1 PD1 F1 C2 (1) C1 (0) MUXOUT CONTROL PRESCALER VALUE P2 P1 POWERDOWN 2 FASTLOCK MODE FUNCTION LATCH PD2 CURRENT SETTING 2 CPI6 CPI5 CPI4 CURRENT SETTING 1 CPI3 CPI2 CPI1 TIMER COUNTER CONTROL TC4 TC3 TC2 TC1 F5 MUXOUT CONTROL DB1 DB0 CP THREESTATE PD POLARITY POWERDOWN 1 COUNTER RESET DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 F3 F2 M3 M2 M1 PD1 F1 P2 P1 PD2 CURRENT SETTING 2 CPI6 CPI5 CPI4 CURRENT SETTING 1 CPI3 CPI2 CPI1 TIMER COUNTER CONTROL TC4 TC3 TC2 TC1 FASTLOCK MODE CONTROL BITS PRESCALER VALUE POWERDOWN 2 FASTLOCK ENABLE INITIALIZATION LATCH F5 Figure 22. Latch Summary Rev. 0 | Page 11 of 20 F4 DB0 C2 (1) C1 (1) ADF4107 LOCK DETECT PRECISION Reference Counter Latch Map RESERVED TEST MODE BITS ANTIBACKLASH WIDTH DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 X 0 0 LDP T2 T1 ABP2 ABP1 CONTROL BITS 14-BIT REFERENCE COUNTER R14 R13 R12 R11 R10 R9 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 R8 R7 R6 R5 R4 R3 R2 R1 C2 (0) C1 (0) X = DON’T CARE ABP2 0 0 1 1 ABP1 0 1 0 1 R14 R13 R12 .......... R3 R2 R1 DIVIDE RATIO 0 0 0 0 . . . 0 0 0 0 . . . 0 0 0 0 . . . .......... .......... .......... .......... .......... .......... .......... 0 0 0 1 . . . 0 1 1 0 . . . 1 0 1 0 . . . 1 2 3 4 . . . 1 1 1 1 1 1 1 1 1 1 1 1 .......... .......... .......... .......... 1 1 1 1 0 0 1 1 0 1 0 1 16380 16381 16382 16383 ANTIBACKLASH PULSEWIDTH 2.9ns 1.3ns 6.0ns 2.9ns TEST MODE BITS SHOULD BE SET TO 00 FOR NORMAL OPERATION. LDP 0 1 OPERATION THREE CONSECUTIVE CYCLES OF PHASE DELAY LESS THAN 15ns MUST OCCUR BEFORE LOCK DETECT IS SET. FIVE CONSECUTIVE CYCLES OF PHASE DELAY LESS THAN 15ns MUST OCCUR BEFORE LOCK DETECT IS SET. BOTH OF THESE BITS MUST BE SET TO 0 FOR NORMAL OPERATION. Figure 23. Reference Counter Latch Map Rev. 0 | Page 12 of 20 ADF4107 CP GAIN AB Counter Latch Map RESERVED CONTROL BITS 6-BIT A COUNTER 13-BIT B COUNTER DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 X X G1 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 A6 A5 A4 A3 A2 A1 DB1 DB0 C2 (0) C1 (1) X = DON’T CARE B13 B12 B11 0 0 0 0 . . . 1 1 1 1 0 0 0 0 . . . 1 1 1 1 0 0 0 0 . . . 1 1 1 1 F4 (FUNCTION LATCH) CP GAIN FASTLOCK ENABLE .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... A6 A5 .......... A2 A1 A COUNTER DIVIDE RATIO 0 0 0 0 . . . 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 1 2 3 . . . 60 61 62 63 B3 B2 B1 B COUNTER DIVIDE RATIO 0 0 0 0 . . . 1 1 1 1 0 0 1 1 . . . 0 0 1 1 0 1 0 1 . . . 0 1 0 1 NOT ALLOWED NOT ALLOWED NOT ALLOWED 3 . . . 8188 8189 8190 8191 OPERATION 0 0 CHARGE PUMP CURRENT SETTING 1 IS PERMANENTLY USED. 0 1 1 0 1 1 CHARGE PUMP CURRENT SETTING 2 IS PERMANENTLY USED. CHARGE PUMP CURRENT SETTING 1 IS USED. CHARGE PUMP CURRENT IS SWITCHED TO SETTING 2. THE TIME SPENT IN SETTING 2 IS DEPENDENT ON WHICH FASTLOCK MODE IS USED. SEE FUNCTION LATCH DESCRIPTION. N = BP + A, P IS PRESCALER VALUE SET IN THE FUNCTION LATCH. B MUST BE GREATER THAN OR EQUAL TO A. FOR CONTINUOUSLY ADJACENT VALUES OF (N × FREF), AT THE OUTPUT, NMIN IS (P2 – P). THESE BITS ARE NOT USED BY THE DEVICE AND ARE DON'T CARE BITS. Figure 24. AB Counter Latch Map Rev. 0 | Page 13 of 20 ADF4107 FASTLOCK ENABLE CP THREESTATE PD POLARITY POWERDOWN 1 COUNTER RESET DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 F4 F3 F2 M3 M2 M1 PD1 F1 C2 (1) C1 (0) POWERDOWN 2 FASTLOCK MODE Function Latch Map PRESCALER VALUE P2 P1 PD2 CURRENT SETTING 2 CPI6 CPI5 CURRENT SETTING 1 CPI4 CPI3 CPI2 TIMER COUNTER CONTROL CPI1 TC4 TC3 TC2 TC1 TC4 TC3 TC2 TC1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 3kΩ 1.06 2.12 3.18 4.24 5.30 6.36 7.42 8.50 5.1kΩ 0.625 1.25 1.875 2.5 3.125 3.75 4.375 5.0 CPI6 CPI5 CP14 CPI3 0 0 0 0 1 1 1 1 CPI2 0 0 1 1 0 0 1 1 CPI1 0 1 0 1 0 1 0 1 PD2 PD1 MODE X X 0 1 X 0 1 1 ASYNCHRONOUS POWER-DOWN NORMAL OPERATION ASYNCHRONOUS POWER-DOWN SYNCHRONOUS POWER-DOWN P1 PRESCALER VALUE 0 0 1 1 0 1 0 1 8/9 16/17 32/33 64/65 PHASE DETECTOR POLARITY F1 0 1 NEGATIVE POSITIVE 0 1 CHARGE PUMP OUTPUT 0 1 NORMAL THREE-STATE F4 F5 FASTLOCK MODE 0 1 1 X 0 1 FASTLOCK DISABLED FASTLOCK MODE 1 FASTLOCK MODE 2 TIMEOUT (PFD CYCLES) 3 7 11 15 19 23 27 31 35 39 43 47 51 55 59 63 11kΩ 0.289 0.580 0.870 1.160 1.450 1.730 2.020 2.320 CE PIN F2 F3 ICP (mA) 0 1 1 1 P2 F5 MUXOUT CONTROL Figure 25. Function Latch Map Rev. 0 | Page 14 of 20 CONTROL BITS COUNTER OPERATION NORMAL R, A, B COUNTERS HELD IN RESET M3 M2 M1 OUTPUT 0 0 0 0 0 1 0 0 1 1 1 1 0 0 0 1 0 1 1 1 1 1 0 1 THREE-STATE OUTPUT DIGITAL LOCK DETECT (ACTIVE HIGH) N DIVIDER OUTPUT DVDD R DIVIDER OUTPUT N-CHANNEL OPEN-DRAIN LOCK DETECT SERIAL DATA OUTPUT DGND ADF4107 FASTLOCK ENABLE CP THREESTATE PD POLARITY POWERDOWN 1 COUNTER RESET DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 F4 F3 F2 M3 M2 M1 PD1 F1 C2 (1) C1 (1) POWERDOWN 2 FASTLOCK MODE Initialization Latch Map PRESCALER VALUE P2 P1 PD2 CURRENT SETTING 2 CPI6 CPI5 CURRENT SETTING 1 CPI4 CPI3 CPI2 TIMER COUNTER CONTROL CPI1 TC4 TC3 TC2 TC1 TC4 TC3 TC2 TC1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 3kΩ 1.06 2.12 3.18 4.24 5.30 6.36 7.42 8.50 5.1kΩ 0.625 1.25 1.875 2.5 3.125 3.75 4.375 5.0 CPI6 CPI5 CP14 CPI3 0 0 0 0 1 1 1 1 CPI2 0 0 1 1 0 0 1 1 CPI1 0 1 0 1 0 1 0 1 PD2 PD1 MODE X X 0 1 X 0 1 1 ASYNCHRONOUS POWER-DOWN NORMAL OPERATION ASYNCHRONOUS POWER-DOWN SYNCHRONOUS POWER-DOWN P1 PRESCALER VALUE 0 0 1 1 0 1 0 1 8/9 16/17 32/33 64/65 PHASE DETECTOR POLARITY F1 0 1 NEGATIVE POSITIVE 0 1 CHARGE PUMP OUTPUT 0 1 NORMAL THREE-STATE F4 F5 FASTLOCK MODE 0 1 1 X 0 1 FASTLOCK DISABLED FASTLOCK MODE 1 FASTLOCK MODE 2 TIMEOUT (PFD CYCLES) 3 7 11 15 19 23 27 31 35 39 43 47 51 55 59 63 11kΩ 0.289 0.580 0.870 1.160 1.450 1.730 2.020 2.320 CE PIN F2 F3 ICP (mA) 0 1 1 1 P2 F5 MUXOUT CONTROL Figure 26. Initialization Latch Map Rev. 0 | Page 15 of 20 CONTROL BITS COUNTER OPERATION NORMAL R, A, B COUNTERS HELD IN RESET M3 M2 M1 OUTPUT 0 0 0 0 0 1 0 0 1 1 1 1 0 0 0 1 0 1 1 1 1 1 0 1 THREE-STATE OUTPUT DIGITAL LOCK DETECT (ACTIVE HIGH) N DIVIDER OUTPUT DVDD R DIVIDER OUTPUT N-CHANNEL OPEN-DRAIN LOCK DETECT SERIAL DATA OUTPUT DGND ADF4107 Fastlock Mode Bit Function Latch The on-chip function latch is programmed with C2 and C1 set to 1 and 0, respectively. Figure 25 shows the input data format for programming the function latch. DB10 of the function latch is the fastlock mode bit. When fastlock is enabled, this bit determines which fastlock mode is used. If the fastlock mode bit is 0, then Fastlock Mode 1 is selected; and if the fastlock mode bit is 1, then Fastlock Mode 2 is selected. Counter Reset DB2 (F1) is the counter reset bit. When this bit is 1, the R counter and the AB counters are reset. For normal operation, this bit should be 0. Upon powering up, the F1 bit needs to be disabled (set to 0). Then, the N counter resumes counting in close alignment with the R counter. (The maximum error is one prescaler cycle). Fastlock Mode 1 Power-Down Fastlock Mode 2 DB3 (PD1) and DB21 (PD2) provide programmable powerdown modes. They are enabled by the CE pin. The charge pump current is switched to the contents of Current Setting 2. The device enters fastlock by having a 1 written to the CP gain bit in the AB counter latch. The device exits fastlock under the control of the timer counter. After the timeout period determined by the value in TC4–TC1, the CP gain bit in the AB counter latch is automatically reset to 0 and the device reverts to normal mode instead of fastlock. See Figure 25 for the timeout periods. When the CE pin is low, the device is immediately disabled regardless of the states of PD2 and PD1. In the programmed asynchronous power-down, the device powers down immediately after latching a 1 into the PD1 bit, with 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 PD1 (on condition that a 1 has also been loaded to PD2), then the device will go into power-down on the occurrence of the next charge pump event. When a power-down is activated (either synchronous or asynchronous mode, including CE pin activated power-down), the following events occur: • • • • • • • 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 RFIN input is debiased. The reference input buffer circuitry is disabled. The input register remains active and capable of loading and latching data. MUXOUT Control The on-chip multiplexer is controlled by M3, M2, M1 on the ADF4107. Figure 25 shows the truth table. Fastlock Enable Bit DB9 of the function latch is the fastlock enable bit. Fastlock is enabled only when this bit is 1. The charge pump current is switched to the contents of Current Setting 2. The device enters fastlock by having a 1 written to the CP gain bit in the AB counter latch. The device exits fastlock by having a 0 written to the CP gain bit in the AB counter latch. Timer Counter Control The user has the option of programming two charge pump currents. The intent is that Current Setting 1 is used when the RF output is stable and the system is in a static state. Current Setting 2 is meant to be used when the system is dynamic and in a state of change (i.e., when a new output frequency is programmed). The normal sequence of events is as follows: The user initially decides what the preferred charge pump currents are going to be. For example, the choice may be 2.5 mA as Current Setting 1 and 5 mA as Current Setting 2. At the same time it must be decided how long the secondary current is to stay active before reverting to the primary current. This is controlled by the timer counter control bits, DB14–DB11 (TC4–TC1) in the function latch. The truth table is given in Figure 25. Now, to program a new output frequency, the user simply programs the AB counter latch with new values for A and B. At the same time, the CP gain bit can be set to 1, which sets the charge pump with the value in CPI6–CPI4 for a period of time determined by TC4–TC1. When this time is up, the charge pump current reverts to the value set by CPI3–CPI1. At the same time the CP gain bit in the AB counter latch is reset to 0 and is now ready for the next time that the user wishes to change the frequency. Rev. 0 | Page 16 of 20 ADF4107 Note that there is an enable feature on the timer counter. It is enabled when Fastlock Mode 2 is chosen by setting the fastlock mode bit (DB10) in the function latch to 1. Charge Pump Currents CPI3, CPI2, and CPI1 program Current Setting 1 for the charge pump. CPI6, CPI5, and CPI4 program Current Setting 2 for the charge pump. The truth table is given in Figure 25. Prescaler Value P2 and P1 in the function latch set the prescaler values. The prescaler value should be chosen so that the prescaler output frequency is always less than or equal to 300 MHz. Thus, with an RF frequency of 4 GHz, a prescaler value of 16/17 is valid but a value of 8/9 is not valid. PD Polarity Initialization Latch Method Apply VDD. Program the initialization latch (11 in two LSBs of input word). Make sure that the F1 bit is programmed to 0. Next, do a function latch load (10 in two LSBs of the control word), making sure that the F1 bit is programmed to a 0. Then do an R load (00 in two LSBs). Then do an AB load (01 in two LSBs). When the Initialization Latch is loaded, the following occurs: 1. 2. 3. This bit sets the phase detector polarity bit. See Figure 25. CP Three-State This bit controls the CP output pin. With the bit set high, the CP output is put into three-state. With the bit set low, the CP output is enabled. Initialization Latch The initialization latch is programmed when C2 and C1 are set to 1 and 1. This is essentially the same as the function latch (programmed when C2, C1 = 1, 0). However, when the initialization latch is programmed an additional internal reset pulse is applied to the R and AB counters. This pulse ensures that the AB counter is at load point when the AB counter data is latched and the device will begin counting in close phase alignment. If the latch is programmed for synchronous power-down (CE pin is high; PD1 bit is high; PD2 bit is low), the internal pulse also triggers this power-down. The prescaler reference and the oscillator input buffer are unaffected by the internal reset pulse and so close phase alignment is maintained when counting resumes. When the first AB counter data is latched after initialization, the internal reset pulse is again activated. However, successive AB counter loads after this will not trigger the internal reset pulse. Device Programming after Initial Power-Up After initially powering up the device, there are three ways to program the device. The function latch contents are loaded. An internal pulse resets the R, AB, and timeout counters to load-state conditions and also three-states the charge pump. Note that the prescaler band gap reference and the oscillator input buffer are unaffected by the internal reset pulse, allowing close phase alignment when counting resumes. Latching the first AB counter data after the initialization word will activate the same internal reset pulse. Successive AB loads will not trigger the internal reset pulse unless there is another initialization. CE Pin Method Apply VDD. Bring CE low to put the device into power-down. This is an asychronous power-down in that it happens immediately. Program the function latch (10). Program the R counter latch (00). Program the AB counter latch (01). Bring CE high to take the device out of power-down. The R and AB counters will now resume counting in close alignment. Note that after CE goes high, a duration of 1 µs may be required for the prescaler band gap voltage and oscillator input buffer bias to reach steady state. CE can be used to power the device up and down in order to check for channel activity. The input register does not need to be reprogrammed each time the device is disabled and enabled as long as it has been programmed at least once after VDD was initially applied. Counter Reset Method Apply VDD. Do a Function Latch Load (10 in two LSBs). As part of this, load 1 to the F1 bit. This enables the counter reset. Do an R counter load (00 in two LSBs). Do an AB counter load (01 in two LSBs). Do a Function latch load (10 in two LSBs). As part of this, load 0 to the F1 bit. This disables the counter reset. This sequence provides the same close alignment as the initialization method. It offers direct control over the internal reset. Note that counter reset holds the counters at load point and three-states the charge pump, but does not trigger synchronous power-down. Rev. 0 | Page 17 of 20 ADF4107 APPLICATIONS Other PLL system specifications are: Local Oscillator for LMDS Base Station Transmitter KD = 5.0 mA KV = 80 MHz/V Loop Bandwidth = 70 kHz FPFD = 1 MHz N = 6300 Extra Reference Spur Attenuation = 10 dB Figure 27 below shows the ADF4107 being used with a VCO to produce the LO for an LMDS base station. The reference input signal is applied to the circuit at FREFIN and, in this case, is terminated in 50 Ω. A typical base station system would have either a TCXO or an OCXO driving the reference input without any 50 Ω termination. All of these specifications are needed and used to derive the loop filter component values shown in Figure 27. To have a channel spacing of 1 MHz at the output, the 10 MHz reference input must be divided by 10, using the on-chip reference divider of the ADF4107. Figure 27 gives a typical phase noise performance of −83 dBc/Hz at 1 kHz offset from the carrier. Spurs are better than −70 dBc. The charge pump output of the ADF4107 (Pin 2) drives the loop filter. In calculating the loop filter component values, a number of items need to be considered. In this example, the loop filter was designed so that the overall phase margin for the system would be 45°. The loop filter output drives the VCO, which, in turn, is fed back to the RF input of the PLL synthesizer and also drives the RF output terminal. A T-circuit configuration provides 50 Ω matching between the VCO output, the RF output, and the RFIN terminal of the synthesizer. In a PLL system, it is important to know when the system is in lock. In Figure 27, this is accomplished by using the MUXOUT signal from the synthesizer. The MUXOUT pin can be programmed to monitor various internal signals in the synthesizer. One of these is the LD or lock detect signal. VDD VP RFOUT 100pF 7 1000pF FREFIN 16 15 AVDD DVDD VP 1000pF CP 2 8 REFIN 2 100pF 51Ω 7.5kΩ 100pF 14 1.7kΩ 47pF VCC 10 V956ME01 ADF4107 820pF CE CLK MUXOUT 14 1, 3, 4, 5, 7, 8, 9, 11, 12, 13 LOCK DETECT LE 100pF RFINA 6 51Ω RFINB 5 DGND 5.1kΩ RSET AGND 1 CPGND SPI COMPATIBLE SERIAL BUS DATA 3 4 9 100pF NOTE DECOUPLING CAPACITORS (0.1µF/10pF) ON AVDD, DVDD, VP OF THE ADF4107 AND ON VCC OF THE V956ME01 HAVE BEEN OMITTED FROM THE DIAGRAM TO AID CLARITY. Figure 27. 6.3 GHz Local Oscillator Using the ADF4107 Rev. 0 | Page 18 of 20 18Ω 18Ω 18Ω ADF4107 ADSP2181 Interface Interfacing The ADF4107 has a simple SPI™ compatible serial interface for writing to the device. CLK, DATA, and LE control the data transfer. When LE (Latch Enable) goes high, the 24 bits that have been clocked into the input register on each rising edge of CLK will get 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 833 kHz or one update every 1.2 µs. This is certainly more than adequate for systems that have typical lock times in hundreds of microseconds. Figure 29 shows the interface between the ADF4107 and the ADSP21xx Digital Signal Processor. The ADF4107 needs a 24-bit serial word for each latch write. The easiest way to accomplish this using the ADSP21xx 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 8 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 then write to the transmit register of the DSP. This last operation initiates the autobuffer transfer. ADuC812 Interface SCLK Figure 28 shows the interface between the ADF4107 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 ADF4107 needs a 24-bit word. This is accomplished by writing three 8-bit 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. On first applying power to the ADF4107, it needs four writes (one each to the initialization latch, function latch, R counter latch, and N counter latch) for the output to become active. I/O port lines on the ADuC812 are also used to control powerdown (CE input) and to detect lock (MUXOUT configured as lock detect and polled by the port input). 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 will be 166 kHz. SCLOCK MOSI CLK DATA LE ADuC812 I/O PORTS ADF4107 CE MUXOUT (LOCK DETECT) Figure 28. ADuC812 to ADF4107 Interface DT ADSP21XX TFS CLK DATA LE ADF4107 CE I/O FLAGS MUXOUT (LOCK DETECT) Figure 29. ADSP-21xx to ADF4107 Interface PCB Design Guidelines for Chip Scale Package 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 will 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. This will 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 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. The user should connect the printed circuit board thermal pad to AGND. Rev. 0 | Page 19 of 20 ADF4107 OUTLINE DIMENSIONS 5 .1 0 5 .0 0 4 .9 0 16 9 4 .5 0 4 .4 0 4 .3 0 6 .4 0 BSC 1 8 PIN 1 1 .2 0 MAX 0 .1 5 0 .2 0 0 .0 9 0 .0 5 0 .3 0 0 .1 9 0 .6 5 BSC SEATING PLANE COPLANARITY 0 .1 0 0 .7 5 0 .6 0 0 .4 5 8° 0° COMPLIANT TO JEDEC STANDARDS MO-1 5 3 AB Figure 30. 16-Lead Thin Shrink Small Outline Package [TSSOP] (RU-16)—Dimensions shown in millimeters 0.60 MAX 4.0 BSC SQ 0.60 MAX PIN 1 INDICATOR 1.00 0.90 0.80 SEATING PLANE TOP VIEW 12 ° MAX 16 15 BOTTOM VIEW 3.75 BSC SQ 0.75 0.55 0.35 1.00 MAX 0.65 NOM 0.50 BSC 0.20 REF 0.05 0.02 0.00 20 1 11 10 6 2.25 2.10 SQ 1.95 5 0.30 0.23 0.18 COPLANARITY 0.08 COMPLIANT TO JEDEC STANDARDS MO-220-VGGD-1 Figure 31. 20-Lead Frame Chip Scale Package [LFCSP] (CP-20)—Dimensions shown in millimeters 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. ORDERING GUIDE Model ADF4107BRU ADF4107BRU–REEL ADF4107BRU–REEL7 ADF4107BCP ADF4107BCP–REEL ADF4107BCP–REEL7 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 CP-20 CP-20 RU = Thin Shrink Small Outline Package (TSSOP) CP = Chip Scale Package Contact the factory for chip availability. Note that aluminum bond wire should not be used with the ADF4107 die. © 2003 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective companies. C03338-0-5/03(0) Rev. 0 | Page 20 of 20