a RF PLL Frequency Synthesizers ADF4116/ADF4117/ADF4118 GENERAL DESCRIPTION FEATURES ADF4116: 550 MHz ADF4117: 1.2 GHz ADF4118: 3.0 GHz 2.7 V to 5.5 V Power Supply Separate V P Allows Extended Tuning Voltage in 3 V Systems Selected Charge Pump Currents Dual Modulus Prescaler ADF4116: 8/9 ADF4117/ADF4118: 32/33 3-Wire Serial Interface Digital Lock Detect Power-Down Mode Fast Lock Mode The ADF4116 family of frequency synthesizers can be used to implement local oscillators in the up-conversion and downconversion sections of wireless receivers and transmitters. They consist 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 (5-bit) and B (13-bit) counters, in conjunction with the dual modulus 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). Control of all the on-chip registers is via a simple 3-wire interface. The devices operate with a power supply ranging from 2.7 V to 5.5 V and can be powered down when not in use. APPLICATIONS Base Stations for Wireless Radio (GSM, PCS, DCS, CDMA, WCDMA) Wireless Handsets (GSM, PCS, DCS, CDMA, WCDMA) Wireless LANS Communications Test Equipment CATV Equipment FUNCTIONAL BLOCK DIAGRAM AVDD DVDD VP CPGND REFERENCE ADF4116/ADF4117/ADF4118 14-BIT R COUNTER REFIN PHASE FREQUENCY DETECTOR 14 CHARGE PUMP CP R COUNTER LATCH CLK 21-BIT INPUT REGISTER DATA FUNCTION LATCH 19 LOCK DETECT LE SDOUT A, B COUNTER LATCH 18 FROM FUNCTION LATCH HIGH Z AVDD 13 MUX N = BP + A RFINA PRESCALER P/P +1 RFINB 13-BIT B COUNTER MUXOUT SDOUT LOAD LOAD 5-BIT A COUNTER M3 M2 M1 FLO SWITCH FLO 5 CE AGND DGND 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 which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781/329-4700 World Wide Web Site: http://www.analog.com Fax: 781/326-8703 (c) Analog Devices, Inc., 2001 ADF4116/ADF4117/ADF4118-SPECIFICATIONS1 (AVDD = DVDD = 3 V 10%, 5 V 10%; AVDD VP 6.0 V; AGND = DGND = CPGND = 0 V; TA = TMIN to TMAX unless otherwise noted; dBm referred to 50 .) Parameter B Version B Chips2 Unit RF CHARACTERISTICS RF Input Frequency ADF4116 ADF4117 ADF4118 ADF4118 Maximum Allowable Prescaler Output Frequency3 80/550 0.1/1.2 0.1/3.0 0.2/3.0 80/550 0.1/1.2 0.1/3.0 0.2/3.0 MHz min/max GHz min/max GHz min/max GHz min/max 165 200 -15/0 -10/0 165 200 -15/0 -10/0 MHz max MHz max dBm min/max dBm min/max AVDD, DVDD = 3 V AVDD, DVDD = 5 V AVDD = 3 V AVDD = 5 V 5/100 5/100 MHz min/max Reference Input Sensitivity4 -5 -5 dBm min For f < 5 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 10 100 10 100 pF max A max PHASE DETECTOR FREQUENCY5 55 55 MHz max CHARGE PUMP ICP Sink/Source High Value Low Value Absolute Accuracy ICP Three-State Leakage Current Sink and Source Current Matching ICP vs. VCP ICP vs. Temperature 1 250 2.5 1 3 2 2 1 250 2.5 1 3 2 2 mA typ A typ % typ nA max % typ % typ % typ LOGIC INPUTS VINH, Input High Voltage VINL, Input Low Voltage IINH/IINL, Input Current CIN, Input Capacitance Reference Input Current 0.8 x DVDD 0.2 x DVDD 1 10 100 0.8 x DVDD 0.2 x DVDD 1 10 100 V min V max A max pF max A max LOGIC OUTPUTS VOH, Output High Voltage VOL, Output Low Voltage DVDD - 0.4 0.4 DVDD - 0.4 0.4 V min V max 2.7/5.5 AVDD AVDD/6.0 2.7/5.5 AVDD AVDD/6.0 V min/V max 5.5 5.5 7.5 0.4 1 4.5 4.5 6.5 0.4 1 mA max mA max mA max mA max A typ RF Input Sensitivity REFIN CHARACTERISTICS Reference Input Frequency POWER SUPPLIES AVDD DVDD VP IDD6 (AIDD + DIDD) ADF4116 ADF4117 ADF4118 IP Low-Power Sleep Mode -2- V min/V max Test Conditions/Comments See Figure 3 for Input Circuit. Use a square wave for frequencies below fMIN. Input Level = -10 dBm 0.5 V VCP VP - 0.5 0.5 V VCP VP - 0.5 VCP = VP/2 IOH = 500 A IOL = 500 A AVDD VP 6.0 V See TPC 20a 4.5 mA Typical 4.5 mA Typical 6.5 mA Typical TA = 25C REV. A ADF4116/ADF4117/ADF4118 B Version B Chips2 Unit Test Conditions/Comments -170 -162 -170 -162 dBc/Hz typ dBc/Hz typ Phase Noise Performance8 ADF41169 540 MHz Output ADF411710 900 MHz Output ADF411810 900 MHz Output ADF411711 836 MHz Output ADF411812 1750 MHz Output ADF411813 1750 MHz Output ADF411814 1960 MHz Output -89 -87 -90 -78 -85 -65 -84 -89 -87 -90 -78 -85 -65 -84 dBc/Hz typ dBc/Hz typ dBc/Hz typ dBc/Hz typ dBc/Hz typ dBc/Hz typ dBc/Hz typ @ 25 kHz PFD Frequency @ 200 kHz PFD Frequency @ VCO Output @ 1 kHz Offset and 200 kHz PFD Frequency Note 15 Note 15 @ 300 Hz Offset and 30 kHz PFD Frequency @ 1 kHz Offset and 200 kHz PFD Frequency @ 200 Hz Offset and 10 kHz PFD Frequency @ 1 kHz Offset and 200 kHz PFD Frequency Spurious Signals ADF41169 540 MHz Output ADF411710 900 MHz Output ADF411810 900 MHz Output ADF411711 836 MHz Output ADF411812 1750 MHz Output ADF411813 1750 MHz Output ADF411814 1960 MHz Output -88/-99 -90/-104 -91/-100 -80/-84 -88/-90 -65/-73 -80/-86 -88/-99 -90/-104 -91/-100 -80/-84 -88/-90 -65/-73 -80/-86 dBc typ dBc typ dBc typ dBc typ dBc typ dBc typ dBc typ @ 200 kHz/400 kHz and 200 kHz PFD Frequency Note 15 Note 15 @ 30 kHz/60 kHz and 30 kHz PFD Frequency @ 200 kHz/400 kHz and 200 kHz PFD Frequency @ 10 kHz/20 kHz and 10 kHz PFD Frequency @ 200 kHz/400 kHz and 200 kHz PFD Frequency Parameter NOISE CHARACTERISTICS ADF4118 Phase Noise Floor7 NOTES 1 Operating temperature range is as follows: B Version: -40C to +85C. 2 The B Chip specifications are given as typical values. 3 This is the maximum operating frequency of the CMOS counters. 4 AVDD = DVDD = 3 V; for AVDD = DVDD = 5 V, use CMOS-compatible levels. 5 Guaranteed by design. Sample tested to ensure compliance. 6 AVDD = DVDD = 3 V; RFIN for ADF4116 = 540 MHz; RF IN for ADF4117, ADF4118 = 900 MHz. 7 The synthesizer phase noise floor is estimated by measuring the in-band phase noise at the output of the VCO and subtracting 20 log N (where N is the N divider value). 8 The phase noise is measured with the EVAL-ADF411xEB Evaluation Board and the HP8562E Spectrum Analyzer. The spectrum analyzer provides the REFIN for the synthesizer (f REFOUT = 10 MHz @ 0 dBm). 9 fREFIN = 10 MHz; fPFD = 200 kHz; Offset frequency = 1 kHz; f RF = 540 MHz; N = 2700; Loop B/W = 20 kHz. 10 fREFIN = 10 MHz; fPFD = 200 kHz; Offset frequency = 1 kHz; f RF = 900 MHz; N = 4500; Loop B/W = 20 kHz. 11 fREFIN = 10 MHz; fPFD = 30 kHz; Offset frequency = 300 Hz; f RF = 836 MHz; N = 27867; Loop B/W = 3 kHz. 12 fREFIN = 10 MHz; fPFD = 200 kHz; Offset frequency = 1 kHz; f RF = 1750 MHz; N = 8750; Loop B/W = 20 kHz. 13 fREFIN = 10 MHz; fPFD = 10 kHz; Offset frequency = 200 Hz; f RF = 1750 MHz; N = 175000; Loop B/W = 1 kHz. 14 fREFIN = 10 MHz; fPFD = 200 kHz; Offset frequency = 1 kHz; f RF = 1960 MHz; N = 9800; Loop B/W = 20 kHz. 15 Same conditions as above. Specifications subject to change without notice. (AVDD = DVDD = 3 V 10%, 5 V 10%; AVDD VP < 6.0 V; AGND = DGND = CPGND = 0 V; A MIN to TMAX unless otherwise noted.) TIMING CHARACTERISTICS1 T = T 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 NOTES 1 Guaranteed by design but not production tested. Specifications subject to change without notice. REV. A -3- ADF4116/ADF4117/ADF4118 CSP JA Thermal Impedance (Paddle Soldered) . . . . . . . . . . . . . . . . . . . . . . . . . 122C/W (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 . . . . . . . . . . . . . . . . . . . . . . -0.3 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 TSSOP JA Thermal Impedance . . . . . . . . . . . . . 150.4C/W 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 kV and it is ESD sensitive. Proper precautions should be taken for handling and assembly. 3 GND = AGND = DGND = 0 V. TRANSISTOR COUNT 6425 (CMOS) and 303 (Bipolar). 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 ORDERING GUIDE Model Temperature Range Package Description Package Option* ADF4116BRU ADF4117BRU ADF4118BRU -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) RU-16 RU-16 RU-16 *Contact the 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 ADF4116/ADF4117/ADF4118 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. -4- WARNING! ESD SENSITIVE DEVICE REV. A ADF4116/ADF4117/ADF4118 PIN FUNCTION DESCRIPTIONS Pin No. Mnemonic Function 1 FLO 2 CP 3 4 5 CPGND AGND RFINB 6 7 RFINA AVDD 8 REFIN 9 10 DGND CE 11 CLK 12 DATA 13 LE 14 MUXOUT 15 DVDD 16 VP Fast Lock Switch Output. This can be used to switch an external resistor to change the loop filter bandwidth. This will speed up locking of the PLL. Charge Pump Output. When enabled, this provides the 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 for 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 3. Input to the RF Prescaler. This small signal input is ac-coupled from the VCO. Analog Power Supply. This may range 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 be the same value as DVDD. Reference Input. This is a CMOS input with a nominal threshold of VDD/2 and an equivalent input resistance of 100 k. See Figure 2. The oscillator 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 threestate 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 21-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 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 with a tuning range of up to 6 V. PIN CONFIGURATION TSSOP FLO 1 16 VP CP 2 15 DVDD 14 MUXOUT CPGND 3 ADF4116 ADF4117 ADF4118 LE TOP VIEW RFINB 5 (Not to Scale) 12 DATA AGND 4 REV. A 13 RFINA 6 11 CLK AVDD 7 10 CE REFIN 8 9 DGND -5- ADF4116/ADF4117/ADF4118-Typical Performance Characteristics 10dB/DIVISION -40 FREQ- PARAM-TYPE DATA-FORMAT KEYWORD IMPEDANCEUNIT OHMS GHz S MA R 50 MagS11 AngS11 FREQ MagS11 AngS11 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85 0.90 0.89207 0.8886 0.89022 0.96323 0.90566 0.90307 0.89318 0.89806 0.89565 0.88538 0.89699 0.89927 0.87797 0.90765 0.88526 0.81267 0.90357 0.92954 -2.0571 -4.4427 -6.3212 -2.1393 -12.13 -13.52 -15.746 -18.056 -19.693 -22.246 -24.336 -25.948 -28.457 -29.735 -31.879 -32.681 -31.522 -34.222 0.95 1.00 1.05 1.10 1.15 1.20 1.25 1.30 1.35 1.40 1.45 1.50 1.55 1.60 1.65 1.70 1.75 1.80 0.92087 0.93788 0.9512 0.93458 0.94782 0.96875 0.92216 0.93755 0.96178 0.94354 0.95189 0.97647 0.98619 0.95459 0.97945 0.98864 0.97399 0.97216 -36.961 -39.343 -40.134 -43.747 -44.393 -46.937 -49.6 -51.884 -51.21 -53.55 -56.786 -58.781 -60.545 -61.43 -61.241 -64.051 -66.19 -63.775 0.64 rms -60 -70 -80 -90 -100 -110 -120 -130 -140 100Hz TPC 1. S-Parameter Data for the ADF4118 RF Input (Up to 1.8 GHz) 10dB/DIVISION -40 PHASE NOISE - dBc/Hz RF INPUT POWER - dBm -25 TA = -40C -30 -35 -70 -80 -90 -100 -110 -120 TA = +85C -130 TA = +25C 0.5 1.0 1.5 2.0 2.5 3.0 RF INPUT FREQUENCY - GHz 3.5 -140 100Hz 4.0 TPC 2. Input Sensitivity (ADF4118) 1MHz 0 REFERENCE LEVEL = -4.2dBm -10 -20 VDD = 3V, VP = 5V -10 ICP = 1mA PFD FREQUENCY = 200kHz LOOP BANDWIDTH = 20kHz -30 OUTPUT POWER - dB OUTPUT POWER - dB FREQUENCY OFFSET FROM 900MHz CARRIER TPC 5. ADF4118 Integrated Phase Noise (900 MHz, 200 kHz, 20 kHz, Typical Lock Time: 400 s) 0 RES. BANDWIDTH = 10Hz -40 VIDEO BANDWIDTH = 10Hz SWEEP = 1.9 SECONDS -50 AVERAGES = 22 -60 -90.2dBc/Hz -70 LOOP BANDWIDTH = 20kHz RES. BANDWIDTH = 1kHz -40 VIDEO BANDWIDTH = 1kHz -50 SWEEP = 2.5 SECONDS AVERAGES = 4 -60 -70 -90 900MHz +1kHz -100 +2kHz TPC 3. ADF4118 Phase Noise (900 MHz, 200 kHz, 20 kHz) ICP = 1mA PFD FREQUENCY = 200kHz -90 -1kHz VDD = 3V, VP = 5V -30 -80 -2kHz REFERENCE LEVEL = -3.8dBm -20 -80 -100 RMS NOISE = 0.575 0.575 rms -20 0 RL = -40dBc/Hz -60 -15 -40 1MHz -50 VDD = 3V VP = 3V -10 -45 FREQUENCY OFFSET FROM 900MHz CARRIER TPC 4. ADF4118 Integrated Phase Noise (900 MHz, 200 kHz, 35 kHz, Typical Lock Time: 200 s) 0 -5 RMS NOISE = 0.64 -50 PHASE NOISE - dBc/Hz FREQ RL = -40dBc/Hz -91.5dBc -400kHz -200kHz 900MHz +200kHz +400kHz TPC 6. ADF4118 Reference Spurs (900 MHz, 200 kHz, 20 kHz) -6- REV. A ADF4116/ADF4117/ADF4118 0 REFERENCE LEVEL = -4.2dBm -10 0 VDD = 3V, VP = 5V PFD FREQUENCY = 200kHz -20 REFERENCE LEVEL = -7.0dBm -10 ICP = 1mA -40 VIDEO BANDWIDTH = 1kHz LOOP BANDWIDTH = 5kHz OUTPUT POWER - dB OUTPUT POWER - dB RES. BANDWIDTH = 1kHz SWEEP = 2.5 SECONDS -50 AVERAGES = 10 -60 -70 RES. BANDWIDTH = 300Hz -40 VIDEO BANDWIDTH = 300Hz SWEEP = 4.2ms -72.3dBc -70 -80 -80 -90 -400kHz -200kHz 900MHz +200kHz -100 +400kHz AVERAGES = 20 -60 -90 TPC 7. ADF4118 Reference Spurs (900 MHz, 200 kHz, 35 kHz) -60kHz -30kHz 1750MHz +30kHz +60kHz TPC 10. ADF4118 Reference Spurs (1750 MHz, 30 kHz, 3 kHz) 0 0 REFERENCE LEVEL = -7.0dBm -10 -20 VDD = 3V, VP = 5V ICP = 1mA -10 PFD FREQUENCY = 30kHz -20 REFERENCE LEVEL = -10.3dBm -30 RES. BANDWIDTH = 10kHz -40 VIDEO BANDWIDTH = 10kHz SWEEP = 477ms -50 AVERAGES = 25 -60 -70 VDD = 3V, VP = 5V ICP = 1mA PFD FREQUENCY = 1MHz LOOP BANDWIDTH = 5kHz OUTPUT POWER - dB OUTPUT POWER - dB -30 -50 -90.67dBc -100 ICP = 5mA PFD FREQUENCY = 30kHz -20 LOOP BANDWIDTH = 35kHz -30 VDD = 3V, VP = 5V LOOP BANDWIDTH = 100kHz -30 RES. BANDWIDTH = 10Hz VIDEO BANDWIDTH = 10Hz -40 SWEEP = 1.9 SECONDS -50 AVERAGES = 26 -60 -85.2dBc/Hz -70 -71.5dBc/Hz -80 -80 -90 -90 -100 -400kHz -200kHz 1750MHz +200kHz -100 +400kHz TPC 8. ADF4118 Phase Noise (1750 MHz, 30 kHz, 3 kHz) 10dB/DIVISION -40 RL = -40dBc/Hz -2kHz RMS NOISE = 2.0 10dB/DIVISION -40 +2kHz RL = -40dBc/Hz RMS NOISE = 1.552 1.55 rms -60 -60 PHASE NOISE - dBc/Hz PHASE NOISE - dBc/Hz +1kHz -50 2.0 rms -70 -80 -90 -100 -110 -70 -80 -90 -100 -110 -120 -120 -130 -130 FREQUENCY OFFSET FROM 1.75GHz CARRIER -140 100Hz 1MHz TPC 9. ADF4118 Integrated Phase Noise (1750 MHz, 30 kHz, 3 kHz) REV. A 2800MHz TPC 11. ADF4118 Phase Noise (2800 MHz, 1 MHz, 100 kHz) -50 -140 100Hz -1kHz FREQUENCY OFFSET FROM 2.8GHz CARRIER 1MHz TPC 12. ADF4118 Integrated Phase Noise (2800 MHz, 1 MHz, 100 kHz) -7- ADF4116/ADF4117/ADF4118 -60 0 REFERENCE LEVEL = -9.3dBm -10 VDD = 3V, VP = 5V -20 FIRST REFERENCE SPUR - dBc PFD FREQUENCY = 1MHz OUTPUT POWER - dB LOOP BANDWIDTH = 100kHz -30 RES. BANDWIDTH = 3kHz VIDEO BANDWIDTH = 3kHz -40 SWEEP = 1.4 SECONDS -50 VDD = 3V VP = 5V ICP = 1mA AVERAGES = 4 -60 -77.3dBc -70 -80 -70 -80 -90 -90 -100 -2MHz -1MHz 2800MHz +1MHz -100 -40 +2MHz -20 0 20 40 60 80 100 TEMPERATURE - C TPC 13. ADF4118 Reference Spurs (2800 MHz, 1 MHz, 100 kHz) TPC 16. ADF4118 Reference Spurs vs. Temperature (900 MHz, 200 kHz, 20 kHz) -130 5 VDD = 3V VP = 5V FIRST REFERENCE SPUR - dBc -135 PHASE NOISE - dBc/Hz -140 -145 -150 -155 -160 -165 -170 -175 VDD = 3V VP = 5V -5 -15 -25 -35 -45 -55 -65 -75 -85 -95 1 100 1000 10 PHASE DETECTOR FREQUENCY - kHz -105 10000 0 1 2 3 4 TPC 14. ADF4118 Phase Noise (Referred to CP Output) vs. PFD Frequency TPC 17. ADF4118 Reference Spurs (200 kHz) vs. VTUNE (900 MHz, 200 kHz, 20 kHz) -60 -60 VDD = 3V VP = 5V -70 PHASE NOISE - dBc/Hz PHASE NOISE - dBc/Hz VDD = 3V VP = 5V -80 -90 -100 -40 5 TURNING VOLTAGE -20 0 20 40 60 80 -70 -80 -90 100 TEMPERATURE - C 0 20 40 60 80 100 TEMPERATURE - C TPC 15. ADF4118 Phase Noise vs. Temperature (900 MHz, 200 kHz, 20 kHz) TPC 18. ADF4118 Phase Noise vs. Temperature (836 MHz, 30 kHz, 3 kHz) -8- REV. A ADF4116/ADF4117/ADF4118 3.0 VDD = 3V VP = 5V 2.5 -70 2.0 DIDD - mA FIRST REFERENCE SPUR - dBc -60 -80 1.5 1.0 -90 -100 0.5 0 20 40 60 80 0.0 100 0 50 TEMPERATURE - C 100 150 200 PRESCALER OUTPUT FREQUENCY - MHz TPC 19. ADF4118 Reference Spurs vs. Temperature (836 MHz, 30 kHz, 3 kHz) TPC 20. DIDD vs. Prescaler Output Frequency (ADF4116, ADF4117, ADF4118) 1.2 1.0 VP = 5V 0.8 ICP SETTING : 1mA 0.6 ICP - mA 0.4 0.2 0 -0.2 -0.4 -0.6 -0.8 -1.0 -1.2 0 0.5 1.0 1.5 2.0 2.5 3.0 VCP - Volts 3.5 4.0 4.5 5.0 TPC 21. Charge Pump Output Characteristics for ADF4116, ADF4117, ADF4118 CIRCUIT DESCRIPTION REFERENCE INPUT SECTION RF INPUT STAGE The reference input stage is shown below 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. The RF input stage is shown in Figure 3. It is followed by a 2-stage limiting amplifier to generate the CML clock levels needed for the prescaler. BIAS GENERATOR POWER-DOWN CONTROL 500 NC AVDD 500 100k SW2 REFIN NC 1.6V RFINA TO R COUNTER BUFFER SW1 RFINB SW3 NO AGND Figure 2. Reference Input Stage REV. A Figure 3. RF Input Stage -9- ADF4116/ADF4117/ADF4118 PRESCALER (P/P + 1) VP The dual modulus prescale (P/P + 1), along with the A and B counters, enables the large division ratio, N, to be realized, (N = PB + A). The dual-modulus prescaler takes the CML 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 for the ADF4116, and set to 32/33 for the ADF4117 and ADF4118. It is based on a synchronous 4/5 core. HI D1 Q1 CHARGE PUMP UP U1 R DIVIDER CLR1 CP DELAY 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 200 MHz or less. CLR2 HI D2 Pulse Swallow Function Q2 U3 DOWN U2 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: N DIVIDER CP GND R DIVIDER fVCO = [(P x B) + A] x fREFIN/R N DIVIDER fVCO Output Frequency of external voltage controlled oscillator (VCO). P Preset modulus of dual modulus prescaler. B Preset Divide Ratio of binary 13-bit counter (3 to 8191). A Preset Divide Ratio of binary 5-bit swallow counter (0 to 31). CP OUTPUT MUXOUT AND LOCK DETECT fREFIN Output frequency of the external reference frequency oscillator. R Figure 5. PFD Simplified Schematic and Timing (In Lock) The output multiplexer on the ADF4116 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. Preset divide ratio of binary 14-bit programmable reference counter (1 to 16383). R COUNTER DVDD The 14-bit R counter allows the input reference frequency to be divided down to produce the input clock to the phase frequency detector (PFD). Division ratios from 1 to 16,383 are allowed. ANALOG LOCK DETECT DIGITAL LOCK DETECT R COUNTER OUTPUT N COUNTER OUTPUT SDOUT N = BP + A 13-BIT B COUNTER FROM RF INPUT STAGE PRESCALER P/P + 1 MODULUS CONTROL TO PFD MUX MUXOUT CONTROL LOAD LOAD 5-BIT A COUNTER DGND Figure 6. MUXOUT Circuit Lock Detect Figure 4. A and B Counters MUXOUT can be programmed for two types of lock detect: Digital Lock Detect and Analog Lock Detect. PHASE FREQUENCY DETECTOR (PFD) AND CHARGE PUMP 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 fixed delay element that sets the width of the antibacklash pulse. This 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. Digital Lock Detect is active high. It is set high when the phase error on three consecutive phase detector cycles is less than 15 ns. It will stay set high until a phase error of greater than 25 ns is detected on any subsequent PD cycle. The N-channel open-drain analog lock detect should be operated with an external pull-up resistor of 10 k nominal. When lock has been detected it is high with narrow low-going pulses. -10- REV. A ADF4116/ADF4117/ADF4118 INPUT SHIFT REGISTER Table I. C2, C1 Truth Table The ADF4116 family digital section includes a 21-bit input shift register, a 14-bit R counter and an 18-bit N counter, comprising a 5-bit A counter and a 13-bit B counter. Data is clocked into the 21-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, DB0 as shown in the timing diagram of Figure 1. The truth table for these bits is shown in Table VI. Table I shows a summary of how the latches are programmed. Control Bits C2 C1 Data Latch 0 0 1 1 R Counter N Counter (A and B) Function Latch Initialization Latch 0 1 0 1 Table II. ADF4116 Family Latch Summary LOCK DETECT PRECISION REFERENCE COUNTER LATCH TEST MODE BITS CONTROL BITS 14-BIT REFERENCE COUNTER, R DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 LDP T4 T3 T2 T1 R14 R13 R12 R11 R10 R9 R8 R7 R6 R5 R4 R3 R2 R1 C2 (0) C1 (0) CP GAIN AB COUNTER LATCH 13-BIT B COUNTER CONTROL BITS 5-BIT A COUNTER DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 G1 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 A5 A4 A3 A2 A1 C2 (0) C1 (1) POWERDOWN 1 COUNT RESETER DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 X X TC4 TC3 TC2 TC1 F6 X F4 F3 F2 M3 M2 M1 PD1 F1 C2 (1) C1 (0) PHASE DETECTOR POLARITY DB17 X CP THREESTATE DB18 PD2 FASTLOCK ENABLE DB19 X TIMER COUNTER CONTROL RESERVED RESERVED POWERDOWN 2 DB20 FASTLOCK MODE RESERVED FUNCTION LATCH MUXOUT CONTROL CONTROL BITS RESERVED POWERDOWN 2 FASTLOCK MODE RESERVED FASTLOCK ENABLE CP THREESTATE PHASE DETECTOR POLARITY POWERDOWN 1 COUNT RESETER INITIALIZATION LATCH DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 X PD2 X X X TC4 TC3 TC2 TC1 F6 X F4 F3 F2 M3 M2 M1 PD1 F1 C2 (1) C1 (1) REV. A TIMER COUNTER CONTROL RESERVED -11- MUXOUT CONTROL CONTROL BITS ADF4116/ADF4117/ADF4118 LOCK DETECT PRECISION Table III. Reference Counter Latch Map TEST MODE BITS CONTROL BITS 14-BIT REFERENCE COUNTER, R DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 LDP T4 T3 T2 T1 R14 R13 R12 R11 R10 R9 R8 R7 R6 R5 R4 R3 R2 R1 C2 (0) C1 (0) R14 R13 R12 ********** R3 R2 R1 DIVIDE RATIO 0 0 0 ********** 0 0 1 1 0 0 0 ********** 0 1 0 2 0 0 0 ********** 0 1 1 3 0 0 0 ********** 1 0 0 4 * * * ********** * * * * * * * ********** * * * * * * * ********** * * * * 1 1 1 ********** 1 0 0 163 80 1 1 1 ********** 1 0 1 163 81 1 1 1 ********** 1 1 0 163 82 1 1 1 ********** 1 1 1 163 83 TEST MODE BITS SHOULD BE SET TO 0000 FOR NORMAL OPERATION LDP 0 1 OPERATION 3 CONSECUTIVE CYCLES OF PHASE DELAY LESS THAN 15ns MUST OCCUR BEFORE LOCK DETECT IS SET. 5 CONSECUTIVE CYCLES OF PHASE DELAY LESS THAN 15ns MUST OCCUR BEFORE LOCK DETECT IS SET. -12- REV. A ADF4116/ADF4117/ADF4118 CP GAIN Table IV. AB Counter Latch Map 13-BIT B COUNTER CONTROL BITS 5-BIT A COUNTER DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 G1 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 A5 A4 A3 A2 A1 C2 (0) C1 (1) ADF4116 ADF4117/ADF4118 LDP A4 A3 A2 A1 A COUNTER DIVIDE RATIO X X 0 0 0 0 X X 0 0 1 1 * * * * * * * * * * * * X X 1 1 0 6 X X 1 1 1 7 A5 A4 A3 A2 A1 A COUNTER DIVIDE RATIO 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 1 0 2 * * * * * * * * * * * * 1 1 1 0 1 29 1 1 1 1 0 30 1 1 1 1 1 31 B13 B12 B11 ********** B3 B2 B1 B COUNTER DIVIDE RATIO 0 0 0 ********** 0 0 1 NOT ALLOWED 0 0 0 ********** 0 1 0 NOT ALLOWED 0 0 0 ********** 0 1 1 3 0 0 0 ********** 1 0 0 4 * * * ********** * * * * * * * ********** * * * * * * * ********** * * * * 1 1 1 ********** 1 0 0 8188 1 1 1 ********** 1 0 1 8189 1 1 1 ********** 1 1 0 8190 1 1 1 ********** 1 1 1 8191 CURRENT SETTINGS 0 250A 1 1mA REV. A A5 N = BP + A, P IS PRESCALER VALUE. B MUST BE GREATER THAN OR EQUAL TO A. FOR CONTINUOUSLY ADJACENT VALUES OF NX FREF, NMIN IS (P2-P). -13- ADF4116/ADF4117/ADF4118 CP THREESTATE PHASE DETECTOR POLARITY POWERDOWN 1 COUNT RESETER DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 X PD2 X X X TC4 TC3 TC2 TC1 F6 X F4 F3 F2 M3 M2 M1 PD1 F1 C2 (1) C1 (0) FASTLOCK ENABLE DB19 TIMER COUNTER CONTROL RESERVED RESERVED POWERDOWN 2 DB20 FASTLOCK MODE RESERVED Table V. Function Latch Map MUXOUT CONTROL COUNTER OPERATION F1 CE PIN PD2 PD1 0 X X CONTROL BITS 0 NORMAL 1 R, A, B COUNTERS HELD IN RESET MODE ASYNCHRONOUS POWER-DOWN M3 M2 M1 0 0 0 THREE-STATE OUTPUT OUTPUT 1 X 0 NORMAL OPERATION 1 0 1 ASYNCHRONOUS POWER-DOWN 0 0 1 DIGITAL LOCK DETECT (ACTIVE HIGH) 1 1 1 SYNCHRONOUS POWER-DOWN 0 1 0 N DIVIDER OUTPUT 0 1 1 AVDD 1 0 0 R DIVIDER OUTPUT 1 0 1 ANALOG LOCK DETECT (N CHANNEL OPEN DRAIN) 1 1 0 SERIAL DATA OUTPUT (INVERSE POLARITY OF SERIAL DATA INPUT) 1 1 1 DGND PHASE DETECTOR POLARITY 0 NEGATIVE 1 POSITIVE F3 CHARGE PUMP OUTPUT 0 NORMAL 1 3-STATE F4 F6 0 X FASTLOCK DISABLED 1 0 FASTLOCK MODE 1 1 1 TC1 F2 FASTLOCK MODE FASTLOCK MODE 2 TIMEOUT (PFD CYCLES) TC4 TC3 TC2 0 0 0 0 0 0 0 1 7 0 0 1 0 11 0 0 1 1 15 0 1 0 0 19 0 1 0 1 23 0 1 1 0 27 0 1 1 1 31 1 0 0 0 35 1 0 0 1 39 1 0 1 0 43 1 0 1 1 47 1 1 0 0 51 1 1 0 1 55 1 1 1 0 59 1 1 1 1 63 3 -14- REV. A ADF4116/ADF4117/ADF4118 RESERVED POWERDOWN 2 FASTLOCK MODE RESERVED FASTLOCK ENABLE CP THREESTATE PHASE DETECTOR POLARITY POWERDOWN 1 COUNT RESETER Table VI. Initialization Latch Map DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 X PD2 X X X TC4 TC3 TC2 TC1 F6 X F4 F3 F2 M3 M2 M1 PD1 F1 C2 (1) C1 (1) RESERVED TIMER COUNTER CONTROL MUXOUT CONTROL COUNTER OPERATION F1 CE PIN PD2 PD1 CONTROL BITS 0 NORMAL 1 R, A, B COUNTERS HELD IN RESET M3 M2 M1 0 0 0 THREE-STATE OUTPUT 0 0 1 DIGITAL LOCK DETECT (ACTIVE HIGH) OUTPUT MODE 0 X X ASYNCHRONOUS POWER-DOWN 1 X 0 NORMAL OPERATION 1 0 1 ASYNCHRONOUS POWER-DOWN 0 1 0 N DIVIDER OUTPUT 1 1 1 SYNCHRONOUS POWER-DOWN 0 1 1 AVDD 1 0 0 R DIVIDER OUTPUT 1 0 1 ANALOG LOCK DETECT (N CHANNEL OPEN DRAIN) 1 1 0 SERIAL DATA OUTPUT (INVERSE POLARITY OF SERIAL DATA INPUT) 1 1 1 DGND F3 REV. A FASTLOCK MODE FASTLOCK DISABLED 1 0 FASTLOCK MODE 1 1 1 TC1 FASTLOCK MODE 2 0 0 0 0 0 0 0 1 7 0 0 1 0 11 0 0 1 1 15 0 1 0 0 19 0 1 0 1 23 0 1 1 0 27 0 1 1 1 31 1 0 0 0 35 1 0 0 1 39 1 0 1 0 43 1 0 1 1 47 1 1 0 0 51 1 1 0 1 55 1 1 1 0 59 1 1 1 1 63 3 -15- POSITIVE CHARGE PUMP OUTPUT THREE-STATE X TC2 NEGATIVE 1 NORMAL F6 TC3 0 1 0 TC4 PHASE DETECTOR POLARITY 0 F4 TIMEOUT (PFD CYCLES) F2 ADF4116/ADF4117/ADF4118 THE FUNCTION LATCH Fastlock Mode Bit 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. DB11 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 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, the N counter resumes counting in "close" alignment with the R counter. (The maximum error is one prescaler cycle.) DB3 (PD1) and DB19 (PD2) on the ADF4116 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. 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 power down is gated by the charge pump to prevent unwanted frequency jumps. Once the power-down is enabled by writing a "1" into bit PD1 (on condition that a "1" has also been loaded to PD2), then the device will go into power-down after the first successive 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 charge pump is forced into three-state mode. The RFIN input is debiased. In the ADF4116 family, the output level of FLO is programmed to a low state and the charge pump current is switched to the high value (1 mA). FLO is used to switch a resistor in the loop filter and ensure stability while in Fastlock by altering the loop bandwidth. The device enters Fastlock by having a "1" written to the CP Gain bit in the N register. 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 register is automatically reset to "0" and the device reverts to normal mode instead of Fastlock. The user must make sure that Fastlock is enabled. Set DB9 of the ADF4116 family to "1." The user must also choose which Fastlock Mode to use. As discussed in the previous section, Fastlock Mode 2 uses the values in the Timer Counter to determine the timeout period before reverting to normal mode operation after Fastlock. Fastlock Mode 2 is chosen by setting DB11 of the ADF4116 family to "1." The oscillator 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 ADF4116 family. Table V shows the truth table. Phase Detector Polarity DB7 (F2) of the function latch 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." DB9 of the Function Latch is the Fastlock Enable Bit. Only when this is "1" is Fastlock enabled. Fastlock Mode 2 When using the Fastlock feature with the ADF4116 family, the normal sequence of events is as follows: The digital clock detect circuitry is reset. Fastlock Enable Bit The device enters Fastlock by having a "1" written to the CP Gain bit in the N register. The device exits Fastlock by having a "0" written to the CP Gain bit in the N register. Timer Counter Control In the ADF4116 family, the user has the option of switching between two charge pump current values to speed up locking to a new frequency. The R, N and timeout counters are forced to their load state conditions. This bit puts the charge pump into three-state mode when programmed to a "1." It should be set to "0" for normal operation. Fastlock Mode 1 In the ADF4116 family, the output level of FLO is programmed to a low state and the charge pump current is switched to the high value (1 mA). FLO is used to switch a resistor in the loop filter and ensure stability while in Fastlock by altering the loop bandwidth. Power-Down Charge Pump Three-State If Fastlock is not enabled (DB9 = "0"), then DB11 (ADF4116) determines the state of the FLO output. FLO state will be the same as that programmed to DB11. The user must also decide how long they want the high current (1 mA) to stay active before reverting to low current (250 A). 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. Now, when the user wishes to program a new output frequency, they can simply program the A, B counter latch with new values for A and B. At the same time they can set the CP Gain bit to a "1," which sets the charge pump 1 mA for a period of time determined by TC4-TC1. When this time is up, the charge pump current reverts to 250 A. At the same time the CP Gain Bit in the A, B Counter latch is reset to 0 and is now ready for the next time that the user wishes to change the frequency again. -16- REV. A ADF4116/ADF4117/ADF4118 The Initialization Latch The CE Pin Method When C2, C1 = 1, 1 then 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 a additional internal reset pulse applied to the R and N counters. This pulse ensures that the N counter is at load point when the N 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 N counter data is latched after initialization, the internal reset pulse is again activated. However, successive N counter loads after this will not trigger the internal reset pulse. 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 N counter will now resume counting in close alignment. Note that after CE goes high, a duration of 1 s may be required for the prescaler bandgap 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 VCC was initially applied. The Counter Reset Method Device Programming After Initial Power-Up Apply VDD. After initially powering up the device, there are three ways to program the device. 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 R Counter Load ("00" in 2 LSBs). 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. Initialization Latch Method Apply VDD. Program the Initialization Latch ("11" in 2 LSBs of input word). Make sure that F1 bit is programmed to "0." Then do an R load ("00" in 2 LSBs). Then do an N load ("01" in 2 LSBs). When the Initialization Latch is loaded, the following occurs: 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 bandgap reference and the oscillator input buffer are unaffected by the internal reset pulse, allowing close phase alignment 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. 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. REV. A -17- ADF4116/ADF4117/ADF4118 APPLICATIONS SECTION Local Oscillator for GSM Base Station Transmitter SHUTDOWN CIRCUIT The attached circuit in Figure 8 shows how to shut down both the ADF4116 family 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. Figure 7 shows the ADF4117/ADF4118 being used with a VCO to produce the LO for a GSM base station transmitter. The reference input signal is applied to the circuit at FREFIN and, in this case, is terminated in 50 . Typical GSM system would have a 13 MHz TCXO driving the Reference Input without any 50 termination. In order to have a channel spacing of 200 kHz (the GSM standard), the reference input must be divided by 65, using the on-chip reference divider of the ADF4117/ADF1118. DIRECT CONVERSION MODULATOR In some applications a direct conversion architecture can be used in base station transmitters. Figure 9 shows the combination available from ADI to implement this solution. The circuit diagram shows the AD9761 being used with the AD8346. The use of dual integrated DACs such as the AD9761 with specified 0.02 dB and 0.004 dB gain and offset matching characteristics ensures minimum error contribution (over temperature) from this portion of the signal chain. The charge pump output of the ADF4117/ADF1118 (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 degrees. Other PLL system specifications are given below: The Local Oscillator (LO) is implemented using the ADF4117/ ADF4118. In this case, the OSC 3B1-13M0 provides the stable 13 MHz reference frequency. The system is designed for a 200 kHz channel spacing and an output center frequency of 1960 MHz. The target application is a WCDMA base station transmitter. Typical phase noise performance from this LO is -85 dBc/Hz at a 1 kHz offset. The LO port of the AD8346 is driven in single-ended fashion. LOIN is ac-coupled to ground with the 100 pF capacitor and LOIP is driven through the ac-coupling capacitor from a 50 source. An LO drive level of between -6 dBm and -12 dBm is required. The circuit of Figure 9 gives a typical level of -8 dBm. KD = 1 mA KV = 12 MHz/V Loop Bandwidth = 20 kHz FREF = 200 kHz N = 4500 Extra Reference Spur Attenuation = 10 dB All of these specifications are needed and used to come up with the loop filter components values shown in Figure 8. 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 matching between the VCO output, the RF output and the RFIN terminal of the synthesizer. The RF output is designed to drive a 50 load but must be ac-coupled as shown in Figure 9. If the I and Q inputs are driven in quadrature by 2 V p-p signals, the resulting output power will be around -10 dBm. In a PLL system, it is important to know when the system is in lock. In Figure 7, 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 RFOUT VP 100pF 7 15 16 AVDD DVDD VP 1000pF 1000pF FREFIN 51 8 CP REFIN ADF4117/ ADF4118 620pF VCO190-902T 100pF 18 18 18 1 10k 1.5nF 3 4 DGND AGND 14 CE LOCK MUXOUT CLK DETECT DATA 100pF LE 6 RFINA 5 51 RFINB CPGND SPI-COMPATIBLE SERIAL BUS 27k 0.15nF FLO VCC 3.3k 2 9 100pF DECOUPLING CAPACITORS (10F/10pF) ON AVDD, DVDD, VP OF THE ADF4117/ADF4118 AND ON VCC OF THE VCO190-902T HAVE BEEN OMITTED FROM THE DIAGRAM TO AID CLARITY. Figure 7. Local Oscillator for GSM Base Station -18- REV. A ADF4116/ADF4117/ADF4118 VP POWER-DOWN CONTROL VDD S VDD GND D 7 15 16 AVDD DVDD VP CE CP 8 REF IN FREFIN DGND AGND 100pF 18 VCO 18 18 10k RFINA CPGND LOOP FILTER GND ADF4116/ ADF4117/ ADF4118 4 100pF VCC 2 1 FLO 3 RFOUT IN ADG702 RFINB 6 100pF 5 51 100pF 9 DECOUPLING CAPACITORS AND INTERFACE SIGNALS HAVE BEEN OMITTED FROM THE DIAGRAM TO AID CLARITY. Figure 8. Local Oscillator Shutdown Circuit 0.1F REFIO IOUTA IOUTB MODULATED DIGITAL DATA IBBP LOW-PASS FILTER IBBP AD9761 TXDAC QBBP LOW-PASS FILTER QOUTB QBBP 2k LOIN LOIP 100pF OSC 3B1-13M0 REFIN SERIAL DIGITAL NTERFACE 100pF 10k CP 1k ADF4118 680pF VCO190-1960T 18pF 100pF 18 6.8nF RFINB 100pF 18 RSET TCXO RFOUT AD8346 QOUTA FS ADJ 100pF VOUT 18 RFINA 100pF 51 POWER SUPPLY CONNECTIONS AND DECOUPLING CAPACITORS ARE OMITTED FROM DIAGRAM FOR CLARITY. Figure 9. Direct Conversion Transmitter Solution INTERFACING The ADF4116 family has a simple SPI-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 get transferred to the appropriate latch. See Figure 1 for the Timing Diagram and Table I for the Latch Truth Table. REV. A 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 microseconds. This is certainly more than adequate for systems that will have typical lock times in hundreds of microseconds. -19- ADF4116/ADF4117/ADF4118 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. ADuC812 Interface Figure 10 shows the interface between the ADF4116 family 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 ADF4116 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. ADuC812 MOSI Figure 11 shows the interface between the ADF4116 family and the ADSP-21xx Digital Signal Processor. The ADF4116 family needs a 21-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. SCLK SCLK SDATA ADSP-21xx ADF4116/ ADF4117/ ADF4118 LE I/O PORTS DT TFS CE I/O FLAGS MUXOUT (LOCK DETECT) SCLK C00392-3-2/01 (rev. A) SCLOCK ADSP-2181 Interface SDATA LE ADF4116/ ADF4117/ ADF4118 CE MUXOUT (LOCK DETECT) Figure 10 ADuC812 to ADF4116 Family Interface Figure 11. ADSP-21xx to ADF4116 Family Interface On first applying power to the ADF4116 family, it requires three writes (one each to the R counter latch, the N counter latch, and the initialization latch) for the output to become active. Set up the word length for 8 bits and use three memory locations for each 24-bit word. To program each 21-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. 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). OUTLINE DIMENSIONS Dimensions shown in inches and (mm). Thin Shrink Small Outline (RU-16) 0.201 (5.10) 0.193 (4.90) 16 9 0.177 (4.50) 0.169 (4.30) 1 PRINTED IN U.S.A. 0.256 (6.50) 0.246 (6.25) 8 PIN 1 0.006 (0.15) 0.002 (0.05) SEATING PLANE 0.0433 (1.10) MAX 0.0256 (0.65) 0.0118 (0.30) BSC 0.0075 (0.19) 0.0079 (0.20) 0.0035 (0.090) -20- 8 0 0.028 (0.70) 0.020 (0.50) REV. A