a 200 MHz Clock Generator PLL ADF4001 FEATURES 200 MHz Bandwidth 2.7 V to 5.5 V Power Supply Separate Charge Pump Supply (VP) Allows Extended Tuning Voltage in 5 V Systems Programmable Charge Pump Currents 3-Wire Serial Interface Hardware and Software Power-Down Mode Analog and Digital Lock Detect Hardware Compatible to the ADF4110/ADF4111/ ADF4112/ADF4113 Typical Operating Current 4.5 mA Ultralow Phase Noise 16-Lead TSSOP 20-Lead LFCSP GENERAL DESCRIPTION The ADF4001 clock generator can be used to implement clock sources for PLLs that require very low noise, stable reference signals. It consists of a low noise digital PFD (phase frequency detector), a precision charge pump, a programmable reference divider, and a programmable 13-bit N counter. 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) or VCXO (voltage controlled crystal oscillator). The N minimum value of 1 allows flexibility in clock generation. APPLICATIONS Clock Generation Low Frequency PLLs Low Jitter Clock Source Clock Smoothing Frequency Translation SONET, ATM, ADM, DSLAM, SDM FUNCTIONAL BLOCK DIAGRAM AVDD DVDD VP RSET CPGND REFERENCE ADF4001 14-BIT R COUNTER REFIN PHASE FREQUENCY DETECTOR 14 CP CHARGE PUMP R COUNTER LATCH DATA 24-BIT INPUT REGISTER 22 FUNCTION LATCH LE CPI3 CPI2 SDOUT CPI1 CPI6 CPI5 CPI4 N COUNTER LATCH HIGH Z AVDD 13 MUXOUT MUX RFINA 13-BIT N COUNTER RFINB SDOUT M3 REV. A CURRENT SETTING 2 CURRENT SETTING 1 LOCK DETECT CLK CE AGND 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. 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. M2 M1 DGND 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 (c) 2003 Analog Devices, Inc. All rights reserved. ADF4001-SPECIFICATIONS1 (AV DD = DVDD = 3 V 10%, 5 V 10%; AVDD VP 6.0 V ; AGND = DGND = CPGND = 0 V; RSET = 4.7 k; TA = TMIN to TMAX, unless otherwise noted; dBm referred to 50 .) Parameter B Version Unit RF CHARACTERISTICS (3 V) RF Input Frequency RF Input Sensitivity 5/165 -10/0 MHz min/max dBm min/max 10/200 20/200 MHz min/max MHz min/max 5/104 MHz min/max REFIN Input Sensitivity2 -5 dBm min REFIN Input Capacitance REFIN Input Current 10 100 pF max A max PHASE DETECTOR Phase Detector Frequency3 55 MHz max CHARGE PUMP ICP Sink/Source High Value Low Value Absolute Accuracy RSET Range ICP Three-State Leakage Current Sink and Source Current Matching ICP vs. VCP ICP vs. Temperature 5 625 2.5 2.7/10 1 2 1.5 2 mA typ A typ % typ k typ nA typ % typ % typ % typ LOGIC INPUTS VINH, Input High Voltage VINL, Input Low Voltage IINH/IINL, Input Current CIN, Input Capacitance 0.8 x DVDD 0.2 x DVDD 1 10 V min V max A max pF max LOGIC OUTPUTS VOH, Output High Voltage VOL, Output Low Voltage DVDD - 0.4 0.4 V min V max 2.7/5.5 AVDD AVDD/6.0 V min/V max V min/V max AVDD VP 6.0 V 5.5 0.4 1 mA max mA max A typ 4.5 mA typical TA = 25C -161 -153 dBc/Hz typ dBc/Hz typ -99 dBc/Hz typ @ 200 kHz PFD Frequency @ 1 MHz PFD Frequency @ VCXO Output @ 1 kHz Offset and 200 kHz PFD Frequency -90/-95 dBc typ/dBc typ @ 200 kHz/400 kHz and 200 kHz PFD Frequency RF CHARACTERISTICS (5 V) RF Input Frequency REFIN CHARACTERISTICS REFIN Input Frequency POWER SUPPLIES AVDD DVDD VP IDD4 (AIDD + DIDD) ADF4001 IP Low Power Sleep Mode NOISE CHARACTERISTICS ADF4001 Phase Noise Floor5 Phase Noise Performance6 200 MHz Output7 Spurious Signals 200 MHz Output7 Test Conditions/Comments See Figure 3 for Input Circuit -5/0 dBm min/max -10/0 dBm min/max See Figure 2 for Input Circuit For f < 5 MHz, Use DC-Coupled Square Wave (0 to VDD) AC-Coupled. When DC-Coupled: 0 to VDD Max (CMOS Compatible) Programmable: See Table V With RSET = 4.7 k With RSET = 4.7 k See Table V 0.5 V VCP VP - 0.5 0.5 V VCP VP - 0.5 VCP = VP/2 IOH = 500 A IOL = 500 A NOTES 1 Operating temperature range (B Version) is -40C to +85C. 2 AVDD = DVDD = 3 V; for AVDD = DVDD = 5 V, use CMOS compatible levels. 3 Guaranteed by design. Sample tested to ensure compliance. 4 TA = 25C; AVDD = DVDD = 3 V; RFIN = 100 MHz. 5 The synthesizer phase noise floor is estimated by measuring the in-band phase noise at the output of the VCO and subtracting 20 logN (where N is the N divider value). 6 The phase noise is measured with the EVAL-ADF4001EB1 evaluation board and the HP8562E spectrum analyzer. 7 fREFIN = 10 MHz; f PFD = 200 kHz; Offset Frequency = 1 kHz; f RF = 200 MHz; N = 1000; Loop B/W = 20 kHz. Specifications subject to change without notice. -2- REV. A ADF4001 TIMING CHARACTERISTICS (AV DD = DVDD = 3 V 10%, 5 V 10%; AVDD VP 6.0 V ; AGND = DGND = CPGND= 0 V; RSET = 4.7 k; TA = TMIN to TMAX, unless otherwise noted; dBm referred to 50 .) Parameter Limit at TMIN to TMAX (B Version) Unit Test Conditions/Comments t1 t2 t3 t4 t5 t6 10 10 25 25 10 20 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 Pulsewidth Guaranteed by design but not production tested. Specifications subject to change without notice. t3 t4 CLOCK t1 DATA DB20 (MSB) t2 DB19 DB2 DB1 (CONTROL BIT C2) DB0 (LSB) (CONTROL BIT C1) t6 LE t5 LE Figure 1. Timing Diagram TSSOP JA Thermal Impedance . . . . . . . . . . . . . . 150.4C/W LFCSP JA Thermal Impedance (Paddle Soldered) . . 122C/W LFCSP JA Thermal Impedance (Paddle Not Soldered) 216C/W Lead Temperature, Soldering Vapor Phase (60 sec) . . . . . . . . . . . . . . . . . . . . . . . . . 215C Infrared (15 sec) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220C ABSOLUTE MAXIMUM RATINGS 1, 2 (TA = 25C, unless otherwise noted.) AVDD to GND3 . . . . . . . . . . . . . . . . . . . . . . . . -0.3 V to +7 V AVDD to DVDD . . . . . . . . . . . . . . . . . . . . . . . . . 0 V to +0.3 V VP to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 V to +7 V VP to AVDD . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 V to +5.5 V Digital I/O Voltage to GND . . . . . . . . . -0.3 V to VDD + 0.3 V Analog I/O Voltage to GND . . . . . . . . . . -0.3 V to VP + 0.3 V REFIN, RFINA, RFINB to GND . . . . . . . -0.3 V to VDD + 0.3 V RFINA to RFINB . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320 mV Operating Temperature Range Industrial (B Version) . . . . . . . . . . . . . . . . -40C to +85C Storage Temperature Range . . . . . . . . . . . . -65C to +150C Maximum Junction Temperature . . . . . . . . . . . . . . . . . . 150C NOTES 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 k and it is ESD sensitive. Proper precautions should be taken for handling and assembly. 3 GND = AGND = DGND = 0 V. ORDERING GUIDE Model Temperature Range Package Description Package Option ADF4001BRU ADF4001BRU-REEL ADF4001BRU-REEL7 ADF4001BCP ADF4001BCP-REEL ADF4001BCP-REEL7 EVAL-ADF4001EB2 -40C to +85C -40C to +85C -40C to +85C -40C to +85C -40C to +85C -40C to +85C 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 RU-16 RU-16 RU-16 CP-20 CP-20 CP-20 *Contact factory for chip availability. 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 the ADF4001 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 -3- WARNING! ESD SENSITIVE DEVICE ADF4001 PIN CONFIGURATIONS LFCSP RSET 1 16 VP CP 2 CPGND 3 20 CP 19 RSET 18 VP 17 DVDD 16 DVDD TSSOP 15 DVDD ADF4001 AGND 4 14 MUXOUT CPGND 1 AGND 2 AGND 3 RFINB 4 RFINA 5 13 LE 11 CLK AVDD 7 10 CE REFIN 8 9 DGND TOP VIEW 15 MUXOUT 14 LE 13 DATA 12 CLK 11 CE AVDD 6 AVDD 7 REFIN 8 DGND 9 DGND 10 TOP VIEW RFINB 5 (Not to Scale) 12 DATA RFINA 6 PIN 1 INDICATOR ADF4001 NOTE: TRANSISTOR COUNT 6425 (CMOS) AND 50 (BIPOLAR) PIN FUNCTION DESCRIPTIONS TSSOP Pin No. LFCSP Pin No. Mnemonic Function 1 19 RSET 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 I CP MAX = 2 20 CP 3 4 5 1 2, 3 4 CPGND AGND RFINB 6 7 5 6, 7 RFINA AVDD 8 8 REFIN 9 10 9, 10 11 DGND CE 11 12 CLK 12 13 DATA 13 14 LE 14 15 MUXOUT 15 16, 17 DVDD 16 18 VP 23.5 RSET So, with RSET = 4.7 k, ICP MAX = 5 mA. Charge Pump Output. When enabled, this provides ICP to the external loop filter which, in turn, drives the external VCO or VCXO. 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 N counter. This point must be decoupled to the ground plane with a small bypass capacitor, typically 100 pF. See Figure 3. Input to the N counter. This small signal input is ac-coupled to the external VCO or VCXO. Analog Power Supply. This ranges from 2.7 V to 5.5 V. Decoupling capacitors to the analog ground plane should be placed as close as possible to this pin. AVDD must have 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 k. See Figure 2. This input can be driven from a TTL or CMOS crystal oscillator or 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 by 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 ranges from 2.7 V to 5.5 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 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 or VCXO with a tuning range of up to 5 V. -4- REV. A Typical Performance Characteristics-ADF4001 10dB/DIVISION -40 0 RL = -40dBc/Hz rms NOISE = 0.229 DEGREES -50 0.229 rms -5 PHASE NOISE - dBc/Hz -60 AMPLITUDE - dBm -10 -15 TA = +85C -20 TA = +25C -25 -70 -80 -90 -100 -110 -120 -30 -130 TA = -40C -140 100 -35 0 50 100 150 FREQUENCY - MHz 200 250 TPC 1. Input Sensitivity, VDD = 3.3 V, 100 pF on RFIN 1k 10k 100k FREQUENCY OFFSET FROM 200MHz CARRIER - Hz TPC 4. Integrated Phase Noise (200 MHz, 200 kHz, 20 kHz) 0 0 -10 -5 -20 OUTPUT POWER - dB AMPLITUDE - dBm 1M -10 -15 -20 REFERENCE LEVEL = -5.7dBm -30 -40 VDD = 3V, VP = 5V ICP = 2.5mA PFD FREQUENCY = 200kHz LOOP BANDWIDTH = 20kHz RES. BANDWIDTH = 300Hz VIDEO BANDWIDTH = 300Hz SWEEP = 4.2 SECONDS AVERAGES = 20 -50 -60 -70 -92.3dBc -80 -25 -90 -30 -100 5 0 10 15 FREQUENCY - MHz 20 25 -200kHz 0 OUTPUT POWER - dB -20 REFERENCE LEVEL = -5.7dBm -30 -40 VDD = 3V, VP = 5V ICP = 2.5mA PFD FREQUENCY = 200kHz LOOP BANDWIDTH = 20kHz RES. BANDWIDTH = 10Hz VIDEO BANDWIDTH = 10Hz SWEEP = 1.9 SECONDS AVERAGES = 26 -50 -60 -70 -99.2dBc/Hz -80 -90 -100 -2kHz -1kHz 200MHz 1kHz 2kHz 0 TPC 3. Phase Noise (200 MHz, 200 kHz, 20 kHz) REV. A 200MHz 100kHz 200kHz 0 TPC 5. Reference Spurs (200 MHz, 200 kHz, 20 kHz) TPC 2. Input Sensitivity, VDD = 3.3 V, 100 pF on RFIN -10 -100kHz -5- ADF4001 FROM N COUNTER LATCH CIRCUIT DESCRIPTION Reference Input Section The reference input stage is shown in Figure 2. 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. 13-BIT N COUNTER FROM RF INPUT STAGE TO PFD Figure 4. N Counter POWER-DOWN CONTROL R Counter NC 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. 100k SW2 REFIN NC BUFFER PHASE FREQUENCY DETECTOR (PFD) AND CHARGE PUMP TO R COUNTER 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 5 is a simplified schematic. The PFD includes a programmable delay element that controls the width of the antibacklash pulse. This pulse ensures that no dead zone is 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 Table III). SW1 SW3 NO Figure 2. Reference Input Stage RF Input Stage The RF input stage is shown in Figure 3. It is followed by a two-stage limiting amplifier to generate the CML clock levels needed for the N counter buffer. VP HI 1.6V BIAS GENERATOR D1 Q1 CHARGE PUMP UP U1 R DIVIDER CLR1 AVDD 2k 2k DELAY CP U3 RFINA RFINB HI AGND N DIVIDER D2 Q2 DOWN U2 CLR2 Figure 3. RF Input Stage CPGND N Counter The N CMOS counter allows a wide ranging division ratio in the PLL feedback counter. Division ratios of 1 to 8191 are allowed. R DIVIDER N DIVIDER N and R Relationship The N counter with the R counter 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 CP OUTPUT Figure 5. PFD Simplified Schematic and Timing (In Lock) fVCO = N R x f REFIN MUXOUT AND LOCK DETECT fVCO is the output frequency of the external voltage cotrolled oscillator (VCO). The output multiplexer on the ADF4001 family allows the user to access various internal points on the chip. The state of MUXOUT is controlled by M3, M2, and M1 in the function latch. Table V shows the full truth table. Figure 6 shows the MUXOUT section in block diagram form. N is the preset divide ratio of the binary 13-bit counter (1 to 8,191). fREFIN is the external reference frequency oscillator. R is the preset divide ratio of the binary 14-bit programmable reference counter (1 to 16,383). -6- REV. A ADF4001 25 ns is detected on any subsequent PD cycle. The N-channel open-drain analog lock detect should be operated with an external pull-up resistor of 10 k nominal. When lock has been detected, this output will be high with narrow low-going pulses. DVDD ANALOG LOCK DETECT INPUT SHIFT REGISTER DIGITAL LOCK DETECT CONTROL MUX The ADF4001 digital section includes a 24-bit input shift register, a 14-bit R counter, and a 13-bit N 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 1. The truth table for these bits is shown in Table I. Table II shows a summary of how the latches are programmed. MUXOUT R COUNTER OUTPUT N COUNTER OUTPUT SDOUT DGND Figure 6. MUXOUT Circuit Table I. C2, C1 Truth Table Lock Detect MUXOUT can be programmed for two types of lock detect: digital lock detect and analog lock detect. Digital lock detect is active high. When LDP in the R counter latch is set to 0, digital lock detect is set high when the phase error on three consecutive phase detector cycles is less than 15 ns. 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 C2 Control Bits C1 0 0 1 1 Data Latch 0 1 0 1 R Counter N Counter Function Latch Initialization Latch Table II. ADF4001 Family Latch Summary LOCK DETECT PRECISION REFERENCE COUNTER LATCH RESERVED DB23 DB22 X X TEST MODE BITS DB21 DB20 DB19 X LDP T2 ANTIBACKLASH WIDTH CONTROL BITS 14-BIT REFERENCE COUNTER DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 T1 ABP2 ABP1 R14 R13 R12 R11 R10 R9 R8 R7 R6 R5 R4 R3 DB3 DB2 DB1 DB0 R2 R1 C2 (0) C1 (0) N COUNTER LATCH RESERVED CP GAIN DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 G1 N13 N12 N11 N10 N9 N8 X X 13-BIT N COUNTER DB14 N7 DB13 N6 CONTROL BITS RESERVED DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 N5 N4 N3 N2 N1 X X X X X X C2 (0) C1 (1) CONTROL BITS RESERVED POWERDOWN 2 FASTLOCK MODE FASTLOCK ENABLE CP THREESTATE PHASE DETECTOR POLARITY POWERDOWN 1 COUNTER RESET FUNCTION LATCH DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 PD2 CPI6 CPI5 CPI4 CPI3 CPI2 CPI1 TC4 TC3 TC2 TC1 F5 F4 F3 F2 M3 M2 M1 PD1 F1 C2 (1) C1 (0) CONTROL BITS X X CURRENT SETTING 2 CURRENT SETTING 1 TIMER COUNTER CONTROL MUXOUT CONTROL DB0 RESERVED POWERDOWN 2 FASTLOCK MODE FASTLOCK ENABLE CP THREESTATE PHASE DETECTOR POLARITY POWERDOWN 1 COUNTER RESET INITIALIZATION LATCH DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 PD2 CPI6 CPI5 CPI4 CPI3 CPI2 CPI1 TC4 TC3 TC2 TC1 F5 F4 F3 F2 M3 M2 M1 PD1 F1 C2 (1) C1 (1) X X CURRENT SETTING 2 CURRENT SETTING 1 TIMER COUNTER CONTROL X = DON'T CARE REV. A -7- MUXOUT CONTROL DB0 ADF4001 LOCK DETECT PRECISION Table III. Reference Counter Latch Map RESERVED DB23 DB22 X X ANTIBACKLASH WIDTH TEST MODE BITS DB21 DB20 DB19 X LDP T2 CONTROL BITS 14-BIT REFERENCE COUNTER DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 T1 ABP2 ABP1 R14 R13 R12 R11 R10 R9 R8 R7 R6 R5 R4 R3 DB3 DB2 DB1 DB0 R2 R1 C2 (0) C1 (0) X = DON'T CARE R14 R13 R12 .......... R3 R2 R1 DIVIDE RATIO 0 0 0 0 . . . 1 0 0 0 0 . . . 1 0 0 0 0 . . . 1 .......... .......... .......... .......... .......... .......... .......... .......... 0 0 0 1 . . . 1 0 1 1 0 . . . 0 1 0 1 0 . . . 0 1 2 3 4 . . . 16380 1 1 1 .......... 1 0 1 16381 1 1 1 .......... 1 1 0 16382 1 1 1 .......... 1 1 1 16383 ABP2 ABP1 ANTIBACKLASH PULSE WIDTH 0 0 1 1 0 1 0 1 2.9ns 1.3ns 6.0ns 2.9ns TEST MODE BITS SHOULD BE SET TO 00 FOR NORMAL OPERATION LDP OPERATION 0 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. 1 -8- REV. A ADF4001 RESERVED CP GAIN Table IV. N Counter Latch Map DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 G1 N13 N12 N11 N10 N9 N8 N7 N6 N5 N4 N3 N2 N1 X X DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 X X X X X X C2 (0) C1 (1) X = DON'T CARE N13 N12 N11 0 0 0 0 . . . 1 0 0 0 0 . . . 1 0 0 0 0 . . . 1 1 1 1 1 1 1 F4 (FUNCTION LATCH) FASTLOCK ENABLE CP GAIN 0 0 0 1 1 0 1 1 N3 N2 N1 N COUNTER DIVIDE RATIO .......... .......... .......... .......... .......... .......... .......... .......... 0 0 0 1 . . . 1 0 1 1 0 . . . 0 1 0 1 0 . . . 0 1 2 3 4 . . . 8188 1 .......... 1 0 1 8189 1 .......... 1 1 0 8190 1 .......... 1 1 1 8191 OPERATION CHARGE PUMP CURRENT SETTING 1 IS PERMANENTLY USED 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. THESE BITS ARE NOT USED BY THE DEVICE AND ARE DON'T CARE BITS. REV. A CONTROL BITS RESERVED 13-BIT N COUNTER -9- ADF4001 RESERVED POWERDOWN 2 FASTLOCK MODE FASTLOCK ENABLE CP THREESTATE PHASE DETECTOR POLARITY POWERDOWN 1 COUNTER RESET Table V. Function Latch Map DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 PD2 CPI6 CPI5 CPI4 CPI3 CPI2 CPI1 TC4 TC3 TC2 TC1 F5 F4 F3 F2 M3 M2 M1 PD1 F1 C2 (1) C1 (0) X X CURRENT SETTING 2 CURRENT SETTING 1 TIMER COUNTER CONTROL MUXOUT CONTROL CONTROL BITS DB0 X = DON'T CARE F2 0 1 FASTLOCK MODE FASTLOCK DISABLED FASTLOCK MODE 1 FASTLOCK MODE 2 TIMEOUT (PFD CYCLES) 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 3 7 11 15 19 23 27 31 35 39 43 47 51 55 59 63 CP14 CPI1 2.7k 4.7k 10k 0 0 0 0 1 1 1 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1 1.088 2.176 3.264 4.352 5.44 6.528 7.616 8.704 0.625 1.25 1.875 2.5 3.125 3.75 4.375 5.0 0.294 0.588 0.882 1.176 1.47 1.764 2.058 2.352 THREE-STATE F5 TC1 CPI5 NORMAL 1 X 0 1 TC2 CPI2 CHARGE PUMP OUTPUT 0 0 1 1 TC3 CPI6 F3 F4 TC4 CPI3 PHASE DETECTOR POLARITY NEGATIVE POSITIVE F1 0 1 COUNTER OPERATION NORMAL R, N COUNTER HELD IN RESET M3 M2 M1 OUTPUT 0 0 0 0 1 1 0 0 1 1 0 0 0 1 0 1 0 1 1 1 1 1 0 1 THREE-STATE OUTPUT DIGITAL LOCK DETECT N DIVIDER OUTPUT AVDD R DIVIDER OUTPUT N-CHANNEL OPEN-DRAIN LOCK DETECT SERIAL DATA OUTPUT DGND ICP (mA) CE PIN PD2 PD1 MODE 0 1 1 1 X X 0 1 X 0 1 1 ASYNCHRONOUS POWER-DOWN NORMAL OPERATION ASYNCHRONOUS POWER-DOWN SYNCHRONOUS POWER-DOWN -10- REV. A ADF4001 RESERVED POWERDOWN 2 FASTLOCK MODE FASTLOCK ENABLE CP THREESTATE PHASE DETECTOR POLARITY POWERDOWN 1 COUNTER RESET Table VI. Initialization Latch Map DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 PD2 CPI6 CPI5 CPI4 CPI3 CPI2 CPI1 TC4 TC3 TC2 TC1 F5 F4 F3 F2 M3 M2 M1 PD1 F1 C2 (1) C1 (1) X X CURRENT SETTING 1 CURRENT SETTING 2 TIMER COUNTER CONTROL MUXOUT CONTROL CONTROL BITS DB0 X = DON'T CARE F2 0 1 REV. A FASTLOCK MODE FASTLOCK DISABLED FASTLOCK MODE 1 FASTLOCK MODE 2 TIMEOUT (PFD CYCLES) 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 3 7 11 15 19 23 27 31 35 39 43 47 51 55 59 63 CP14 CPI1 2.7k 4.7k 10k 0 0 0 0 1 1 1 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1 1.088 2.176 3.264 4.352 5.44 6.528 7.616 8.704 0.625 1.25 1.875 2.5 3.125 3.75 4.375 5.0 0.294 0.588 0.882 1.176 1.47 1.764 2.058 2.352 ICP (mA) CE PIN PD2 PD1 MODE 0 1 1 1 X X 0 1 X 0 1 1 ASYNCHRONOUS POWER-DOWN NORMAL OPERATION ASYNCHRONOUS POWER-DOWN SYNCHRONOUS POWER-DOWN THREE-STATE F5 TC1 CPI5 NORMAL 1 X 0 1 TC2 CPI2 CHARGE PUMP OUTPUT 0 0 1 1 TC3 CPI6 F3 F4 TC4 CPI3 PHASE DETECTOR POLARITY NEGATIVE POSITIVE -11- F1 0 1 COUNTER OPERATION NORMAL R, N COUNTER HELD IN RESET M3 M2 M1 OUTPUT 0 0 0 0 1 1 0 0 1 1 0 0 0 1 0 1 0 1 1 1 1 1 0 1 THREE-STATE OUTPUT DIGITAL LOCK DETECT N DIVIDER OUTPUT AVDD R DIVIDER OUTPUT N-CHANNEL OPEN-DRAIN LOCK DETECT SERIAL DATA OUTPUT DGND ADF4001 FUNCTION LATCH Fastlock Mode 1 With C2, C1 set to 1, 0, the on-chip function latch will be programmed. Table V shows the input data format for programming the function latch. The charge pump current is switched to the contents of Current Setting 2. Counter Reset DB2 (F1) is the counter reset bit. When this is 1, the R counter and the A, B counters are reset. For normal operation, this bit should be 0. Upon powering up, the F1 bit needs to be disabled, and the N counter resumes counting in close alignment with the R counter. (The maximum error is one prescaler cycle.) The device enters fastlock by having a 1 written to the CP gain bit in the N counter latch. The device exits fastlock by having a 0 written to the CP gain bit in the AB counter latch. Fastlock Mode 2 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 N 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 N counter latch is automatically reset to 0 and the device reverts to normal mode instead of fastlock. See Table V for the timeout periods. Power-Down DB3 (PD1) and DB21 (PD2) on the ADF4001 family provide programmable power-down modes. They are enabled by the CE pin. When the CE pin is low, the device is immediately disabled regardless of the states of PD2, PD1. Timer Counter Control In the programmed asynchronous power-down, the device powers down immediately after latching a 1 into Bit PD1, with the condition that PD2 has been loaded with a 0. In the programmed synchronous power-down, the device powerdown is gated by the charge pump to prevent unwanted frequency jumps. Once the power-down is enabled by writing a 1 into Bit PD1 (on condition that a 1 has also been loaded to PD2), 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: The user has the option of programming two charge pump currents. The intent is that the 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, they may choose 2.5 mA as Current Setting 1 and 5 mA as Current Setting 2. At the same time, they must also decide how long they want the secondary current to stay active before reverting to the primary current. This is controlled by the Timer Counter Control Bits DB14 to DB11 (TC4-TC1) in the function latch. The truth table is given in Table V. * All active dc current paths are removed. * The R, N, and timeout counters are forced to their load state conditions. Now, when the user wishes to program a new output frequency, they can simply program the N counter latch with new value for N. At the same time, they can set the CP gain bit to a 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 N counter latch is reset to 0 and is now ready for the next time that the user wishes to change the frequency. * The charge pump is forced into three-state mode. * The digital clock 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. The on-chip multiplexer is controlled by M3, M2, M1 on the ADF4001. Table V shows the truth table. 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. Fastlock Enable Bit Charge Pump Currents DB9 of the function latch is the fastlock enable bit. Only when this is 1 is fastlock enabled. CPI3, CPI2, CPI1 program Current Setting 1 for the charge pump. CPI6, CPI5, CPI4 program Current Setting 2 for the charge pump. The truth table is given in Table V. MUXOUT Control Fastlock Mode Bit 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, fastlock mode 1 is selected; if the fastlock mode bit is 1, fastlock mode 2 is selected. PD Polarity This bit sets the PD polarity bit (see Table V). CP Three-State This bit sets 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. -12- REV. A ADF4001 INITIALIZATION LATCH Counter Reset Method When C2, C1 = 1, 1, the initialization latch is programmed. This is essentially the same as the function latch (programmed when C2, C1 = 1, 0). Apply VDD. However, when the initialization latch is programmed, there is an additional internal reset pulse applied to the R and N counters. This pulse ensures that the N counter is at a load point when the N counter data is latched, and the device will begin counting in close phase alignment. Do an R counter load (00 in 2 LSBs). If the latch is programmed for synchronous power-down (the CE pin is high; PD1 bit is high; and PD2 bit is low), the internal pulse also triggers this power-down. The oscillator input buffer is unaffected by the internal reset pulse, so close phase alignment is maintained when counting resumes. 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. The counter reset method requires an extra function latch load compared to the initialization latch method. When the first N counter data is latched after initialization, the internal reset pulse is again activated. However, successive N counter loads 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. Initialization Latch Method Apply VDD. Program the initialization latch (11 in 2 LSB of input word). Make sure that F1 bit is programmed to 0. Do a function latch load (10 in 2 LSBs). As part of this, load 1 to the F1 bit. This enables the counter reset. Do an N counter load (01 in 2 LSBs). Do a function latch load (10 in 2 LSBs). As part of this, load 0 to the F1 bit. This disables the counter reset. APPLICATION Extremely Stable, Low Jitter Reference Clock for GSM Base Station Transmitter Figure 7 shows the ADF4001 being used with a VCXO to produce an extremely stable, low jitter reference clock for a GSM base station local oscillator (LO). 13MHz SYSTEM CLOCK 1 13MHz R DIVIDER CHARGE PUMP PFD Do an R load (00 in 2 LSBs). CP LOOP FILTER VCXO 1 Do an N load (01 in 2 LSBs). RFIN N DIVIDER When the initialization latch is loaded, the following occurs: ADF4001 1. The function latch contents are loaded. 2. An internal pulse resets the R, N, 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. 3. Latching the first N counter data after the initialization word will activate the same internal reset pulse. Successive N 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 asynchronous power-down in that it happens immediately. Program the function latch (10). Program the R counter latch (00). Program the N 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 s may be required for the prescaler band gap voltage and oscillator input buffer bias to reach steady state. REFIN CP VCO RFIN ADF4110 ADF4111 ADF4112 ADF4113 RFINA Figure 7. Low Jitter, Stable Clock Source for GSM Base Station Local Oscillator Circuit The system reference signal is applied to the circuit at REFIN. Typical GSM systems would have a very stable OCXO as the clock source for the entire base station. However, distribution of this signal around the base station makes it susceptible to noise and spurious pickup. It is also open to pulling from the various loads it may need to drive. The charge pump output of the ADF4001 (Pin 2 of the TSSOP) drives the loop filter and the 13 MHz VCXO. The VCXO output is fed back to the RF input of the ADF4001 and also drives the reference (REFIN) for the LO. A T-circuit configuration provides 50 matching between the VCXO output, the LO REFIN, and the RFIN terminal of the ADF4001. CE can be used to power the device up and down 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. REV. A LOOP FILTER -13- ADF4001 COHERENT CLOCK GENERATION 13MHz SYSTEM CLOCK FOR GSM R1 REFIN When testing A/D converters, it is often advantageous to use a coherent test system, that is, a system that ensures a specific relationship between the A/D converter input signal and the A/D converter sample rate. Thus, when doing an FFT on this data, there is no longer any need to apply the window weighting function. Figure 8 shows how the ADF4001 can be used to handle all the possible combinations of the input signal frequency and sampling rate. The first ADF4001 is phase locked to a VCO. The output of the VCO is also fed into the N divider of the second ADF4001. This results in both ADF4001s being coherent with the REFIN. Since the REFIN comes from the signal generator, the MUXOUT signal of the second ADF4001 is coherent with the fIN frequency to the ADC. This is used as fS, the sampling clock. 4 CPRF VCXO 13MHz LOOP FILTER RFIN 1 N1 ADF4001 REFIN 19.44MHz SYSTEM CLOCK FOR WCDMA R2 1300 CPRF 52MHz MASTER CLOCK VCXO 19.44MHz LOOP FILTER RFIN 486 N2 ADF4001 fIN fS = (fIN N1)/(R1 N2) SINE OUTPUT AIN BRUEL & KJAER MODEL 1051 SQUARE OUTPUT A/D CONVERTER UNDER TEST 65 SAMPLING CLOCK REFIN CPRF VCXO 19.2MHz LOOP FILTER RFIN 24 N3 fS ADF4001 R1 ADF4001 19.2MHz SYSTEM CLOCK FOR CDMA R3 REFIN CPRF N1 N2 LOOP FILTER VCO 100MHz Figure 9. Tri-Band System Clock Generation RFIN VP RFIN POWER-DOWN CONTROL NC7S04 MUXOUT S ADF4001 VDD VDD RFOUT IN ADG702 Figure 8. Coherent Clock Generator D GND 100pF TRI-BAND CLOCK GENERATION CIRCUIT In multiband applications, it is necessary to realize different clocks from one master clock frequency. For example, GSM uses a 13 MHz system clock, WCDMA uses 19.44 MHz, and CDMA uses 19.2 MHz. The circuit in Figure 9 shows how to use the ADF4001 to generate GSM, WCDMA, and CDMA system clocks from a single 52 MHz master clock. The low RF fMIN specification and the ability to program R and N values as low as 1 makes the ADF4001 suitable for this. Other fOUT clock frequencies can be realized using the formula 15 7 16 10 AVDD DVDD VP CE CP FREFIN RSET 18 VCC 2 LOOP FILTER 1 10k 100pF 18 VCO OR VCXO 18 GND ADF4001 100pF RFINA 6 fOUT = REFIN x (N / R) 51 RFINB 5 SHUTDOWN CIRCUIT The circuit in Figure 10 shows how to shut down both the ADF4001 and the accompanying VCO. The ADG702 switch goes open circuit when a Logic 1 is applied to the IN input. The low cost switch is available in both SOT-23 and micro SOIC packages. CPGND AGND DGND 3 4 9 100pF DECOUPLING CAPACITORS AND INTERFACE SIGNALS HAVE BEEN OMITTED FROM THE DIAGRAM IN THE INTEREST OF GREATER CLARITY. Figure 10. Local Oscillator Shutdown Circuit -14- REV. A ADF4001 INTERFACING ADSP-2181 Interface The ADF4001 family has a simple SPI(R) compatible serial interface for writing to the device. SCLK, SDATA, 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 SCLK will be transferred to the appropriate latch. See Figure 1 for the Timing Diagram and Table I for the Latch Truth Table. Figure 12 shows the interface between the ADF4001 family and the ADSP-21xx digital signal processor. The ADF4001 family 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 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. 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 ms. This is certainly more than adequate for systems with typical lock times in hundreds of microseconds. ADuC812 Interface SCLK DT TFS 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. ADF4001 ADuC812 SCLOCK MOSI SCLK SDATA LE I/O PORTS CE MUXOUT (LOCK DETECT) Figure 11. ADuC812 to ADF4001 Family Interface REV. A SCLK SDATA LE CE I/O FLAGS On first applying power to the ADF4001 family, it needs three writes (one each to the R counter latch, the N counter latch, and the initialization 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). ADF4001 ADSP-21xx Figure 11 shows the interface between the ADF4001 family and the ADuC812 MicroConverter(R). 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 ADF4001 family 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. MUXOUT (LOCK DETECT) Figure 12. ADSP-21xx to ADF4001 Family Interface PCB DESIGN GUIDELINES FOR CHIP SCALE PACKAGE The leads on the chip package (CP-20) are rectangular. The printed circuit board pad for these should be 0.1 mm longer than the package lead length and 0.05 mm wider than the package lead width. The lead should be centered on the pad to ensure that the solder joint size is maximized. The bottom of the chip scale package has a central thermal pad. The thermal pad on the printed circuit board should be at least as large as this exposed pad. On the printed circuit board, there should be a clearance of at least 0.25 mm between the thermal pad and the inner edge 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. -15- ADF4001 OUTLINE DIMENSIONS 16-Lead Thin Shrink Small Outline Package [TSSOP] (RU-16) C02569-0-10/03(A) Dimensions shown in millimeters 5.10 5.00 4.90 16 9 4.50 4.40 4.30 6.40 BSC 1 8 PIN 1 1.20 MAX 0.15 0.05 0.20 0.09 0.30 0.19 0.65 BSC COPLANARITY 0.10 0.75 0.60 0.45 8 0 SEATING PLANE COMPLIANT TO JEDEC STANDARDS MO-153AB 20-Lead Lead Frame Chip Scale Package [LFCSP] (CP-20) Dimensions shown in millimeters 0.60 MAX 4.0 BSC SQ 0.60 MAX PIN 1 INDICATOR TOP VIEW 3.75 BSC SQ 12 MAX SEATING PLANE 0.50 BSC 0.80 MAX 0.65 NOM 0.20 REF 20 1 2.25 2.10 SQ 1.95 BOTTOM VIEW 0.75 0.55 0.35 1.00 0.90 0.80 16 15 11 10 6 5 0.25 MIN 0.30 0.23 0.18 0.05 0.02 0.00 COPLANARITY 0.08 COMPLIANT TO JEDEC STANDARDS MO-220-VGGD-1 Revision History Location Page 10/03--Data Sheet changed from REV. 0 to REV. A. Changes to SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Edits to ORDERING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Changes to PIN CONFIGURATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Updated OUTLINE DIMENSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Purchase of licensed I 2C components of Analog Devices or one of its sublicensed Associated Companies conveys a license for the purchaser under the Philips I 2C Patent Rights to use these components in an I 2C system, provided that the system conforms to the I 2C Standard Specification as defined by Philips. -16- REV. 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