ADF4150

Fractional-N/Integer-N PLL Synthesizer ADF4150 FEATURES Fractional-N synthesizer and integer-N synthesizer Programmable divide-by-1/-2/-4/-8/-16 output 5.0 GHz RF bandwidth 3.0 V to 3.6 V power supply 1.8 V logic compatibility Separate charge pump supply (VP) allows extended tuning voltage in 3 V systems Programmable dual-modulus prescaler of 4/5 or 8/9 Programmable output power level RF output mute function 3-wire serial interface Analog and digital lock detect Switched bandwidth fast-lock mode Cycle slip reduction GENERAL DESCRIPTION The ADF4150 allows implementation of fractional-N or integer-N phase-locked loop (PLL) frequency synthesizers if used with an external voltage-controlled oscillator (VCO), loop filter, and external reference frequency. The ADF4150 is for use with external VCO parts and is software compatible with the ADF4350. The VCO frequency can be divided by 1/2/4/8/16 to allow the user to generate RF output frequencies as low as 31.25 MHz. For applications that require isolation the RF output stage can be muted. The mute function is both pin and software controllable. Control of all the on-chip registers is through a simple 3-wire interface. The device operates with a power supply ranging from 3.0 V to 3.6 V and can be powered down when not in use. The ADF4150 is available in a 4 mm × 4 mm package. APPLICATIONS Wireless infrastructure (W-CDMA, TD-SCDMA, WiMax, GSM, PCS, DCS, DECT) Test equipment Wireless LANs, CATV equipment Clock generation FUNCTIONAL BLOCK DIAGRAM SDVDD AVDD DVDD VP RSET REFIN ×2 DOUBLER 10-BIT R COUNTER ÷2 DIVIDER LOCK DETECT MULTIPLEXER MUXOUT FLO SWITCH SW LD CLK DATA LE DATA REGISTER FUNCTION LATCH PHASE COMPARATOR CHARGE PUMP CPOUT INTEGER REG FRACTION REG MODULUS REG DIVIDE-BY-1/ -2/-4/-8/-16 OUTPUT STAGE RFOUT+ RFOUT– PDBRF THIRD-ORDER FRACTIONAL INTERPOLATOR MULTIPLEXER RF INPUT RFIN+ RFIN– N COUNTER CE AGND CPGND SDGND 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 owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. www.analog.com Tel: 781.329.4700 Fax: 781.461.3113 ©2011 Analog Devices, Inc. All rights reserved. 08226-001 ADF4150 ADF4150 TABLE OF CONTENTS Features .............................................................................................. 1 Applications ....................................................................................... 1 General Description ......................................................................... 1 Functional Block Diagram .............................................................. 1 Revision History ............................................................................... 2 Specifications..................................................................................... 3 Timing Characteristics ................................................................ 5 Absolute Maximum Ratings ............................................................ 6 Transistor Count ........................................................................... 6 ESD Caution .................................................................................. 6 Pin Configuration and Function Descriptions ............................. 7 Typical Performance Characteristics ............................................. 9 Circuit Description ......................................................................... 11 Reference Input Section ............................................................. 11 RF N Divider ............................................................................... 11 INT, FRAC, MOD, and R Counter Relationship.................... 11 INT N Mode ................................................................................ 11 R Counter .................................................................................... 11 Phase Frequency Detector (PFD) and Charge Pump ............ 11 MUXOUT and Lock Detect ...................................................... 12 Input Shift Registers ................................................................... 12 Program Modes .......................................................................... 12 Output Stage ................................................................................ 12 Register Maps .................................................................................. 13 Register 0 ..................................................................................... 18 Register 1 ..................................................................................... 18 Register 2 ..................................................................................... 18 Register 3 ..................................................................................... 20 Register 4 ..................................................................................... 20 Register 5 ..................................................................................... 20 Initialization Sequence .............................................................. 20 RF Synthesizer—A Worked Example ...................................... 21 Modulus ....................................................................................... 21 Reference Doubler and Reference Divider ............................. 21 12-Bit Programmable Modulus ................................................ 21 Cycle Slip Reduction for Faster Lock Times ........................... 22 Spurious Optimization and Fast lock ...................................... 22 Fast Lock Timer and Register Sequences ................................ 22 Fast Lock—An Example ............................................................ 23 Fast Lock—Loop Filter Topology............................................. 23 Spur Mechanisms ....................................................................... 23 Spur Consistency and Fractional Spur Optimization ........... 24 Phase Resync ............................................................................... 24 Applications Information .............................................................. 25 Direct Conversion Modulator .................................................. 25 Interfacing ................................................................................... 26 PCB Design Guidelines for Chip Scale Package .................... 26 Output Matching ........................................................................ 27 Outline Dimensions ....................................................................... 28 Ordering Guide .......................................................................... 28 REVISION HISTORY 7/11—Revision 0: Initial Version Rev. 0 | Page 2 of 28 ADF4150 SPECIFICATIONS AVDD = DVDD = SDVDD = 3.3 V ± 10%; VP = AVDD to 5.5 V; AGND = DGND = 0 V; TA = TMIN to TMAX, unless otherwise noted. The operating temperature range is −40°C to +85°C. Table 1. Parameter REFIN CHARACTERISTICS Input Frequency Input Sensitivity Input Capacitance Input Current RF INPUT CHARACTERISTICS RF Input Frequency (RFIN), RF Output Buffer Disabled RF Input Frequency (RFIN), RF Output Buffer Disabled RF Input Frequency (RFIN) RF Output Buffer Enabled RF Input Frequency (RFIN) RF Output Buffer and Dividers Enabled Prescaler Output Frequency MAXIMUM PFD FREQUENCY Fractional-N (Low Spur Mode) Fractional-N Mode (Low Noise Mode) Integer-N Mode CHARGE PUMP ICP Sink/Source High Value Low Value RSET Range ICP Leakage Sink and Source Current Matching ICP vs. VCP ICP vs. Temperature LOGIC INPUTS Input High Voltage, VINH Input Low Voltage, VINL Input Current, IINH/IINL Input Capacitance, CIN LOGIC OUTPUTS Output High Voltage, VOH Output High Current, IOH Output Low Voltage, VO POWER SUPPLIES AVDD DVDD, SDVDD VP DIDD + AIDD 2 Output Dividers IRFOUT2 Low Power Sleep Mode Min 10 0.7 B Version Typ Max 250 AVDD 5.0 ±60 4.0 5.0 3.5 3.0 750 26 32 32 Unit MHz V p-p pF µA GHz GHz GHz GHz MHz MHz MHz MHz RSET = 5.1 kΩ 4.65 0.29 2.7 1 2 1 2 1.5 0.6 ±1 3.0 DVDD − 0.4 500 0.4 3.0 AVDD AVDD 50 6 to 24 24 1 5.5 60 32 V mA mA mA µA 3.6 10 mA mA kΩ nA % % % V V µA pF V µA V V CMOS output chosen IOL = 500 µA Conditions/Comments For f < 10 MHz ensure slew rate > 21 V/µs Biased at AVDD/2 1 0.5 0.5 0.5 0.5 −10 dBm ≤ RF input power ≤ +5 dBm −5 dBm ≤ RF input power ≤ +5 dBm −10 dBm ≤ RF input power ≤ +5 dBm −10 dBm ≤ RF input power ≤ +5 dBm VCP = VP/2 0.5 V ≤ VCP ≤ VP − 0.5 V 0.5 V ≤ VCP ≤ VP − 0.5 V VCP = VP/2 Each output divide by two consumes 6 mA RF output stage is programmable Rev. 0 | Page 3 of 28 ADF4150 Parameter RF OUTPUT CHARACTERISTICS Minimum Output Frequency Using RF Output Dividers Maximum RFIN Frequency Using RF Output Dividers Harmonic Content (Second) Harmonic Content (Third) Harmonic Content (Second) Harmonic Content (Third) Output Power 3 Output Power Variation Level of Signal With RF Mute Enabled NOISE CHARACTERISTICS Normalized Phase Noise Floor (PNSYNTH) 4 Normalized 1/f Noise (PN1_f) 5 Normalized Phase Noise Floor (PNSYNTH)4 Normalized 1/f Noise (PN1_f)5 Min 31.25 4400 −19 −13 −20 −10 −4 +5 ±1 −40 −223 B Version Typ Max Unit MHz MHz dBc dBc dBc dBc dBm dBm dB dBm dBc/Hz dBc/Hz dBc/Hz dBc/Hz Conditions/Comments 500 MHz VCO input and divide-by-16 selected Fundamental VCO output Fundamental VCO output Divided VCO output Divided VCO output Maximum setting Minimum setting PLL loop BW = 500 kHz (ABP = 3 ns) 10 kHz offset. Normalized to 1 GHz. (ABP = 3 ns) PLL loop BW = 500 kHz (ABP = 6 ns); low noise mode selected 10 kHz offset; normalized to 1 GHz; (ABP = 6 ns); low noise mode selected VCO output RF output buffers −123 −222 −119 Spurious Signals Due to PFD Frequency 6 1 2 3 −90 −75 dBc dBc AC coupling ensures AVDD/2 bias. TA = 25°C; AVDD = DVDD = 3.3 V; prescaler = 8/9; fREFIN = 100 MHz; fPFD = 26 MHz; fRF = 1.7422 GHz. Using a tuned load. 4 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) and 10 log FPFD. PNSYNTH = PNTOT − 10logFPFD − 20logN. 5 The PLL phase noise is composed of 1/f (flicker) noise plus the normalized PLL noise floor. The formula for calculating the 1/f noise contribution at an RF frequency (FRF) and at a frequency offset (f) is given by PN = P1_f + 10log(10 kHz/f) + 20log(FRF/1 GHz). Both the normalized phase noise floor and flicker noise are modeled in ADIsimPLL. 6 Spurious measured on EVAL-ADF4150EB1Z, using a Rohde & Schwarz FSUP signal source analyzer. Rev. 0 | Page 4 of 28 ADF4150 TIMING CHARACTERISTICS AVDD = DVDD = SDVDD = 3.3 V ± 10%; VP = AVDD to 5.5 V; AGND = DGND = 0 V; TA = TMIN to TMAX, unless otherwise noted. Operating temperature range is −40°C to +85°C. Table 2. Parameter t1 t2 t3 t4 t5 t6 t7 Limit (B Version) 20 10 10 25 25 10 20 Unit ns min ns min ns min ns min ns min ns min ns min Test Conditions/Comments LE setup time DATA to CLK setup time DATA to CLK hold time CLK high duration CLK low duration CLK to LE setup time LE pulse width t4 CLK t5 t2 DATA DB31 (MSB) DB30 t3 DB2 (CONTROL BIT C3) DB1 (CONTROL BIT C2) DB0 (LSB) (CONTROL BIT C1) t7 LE t1 LE t6 08226-002 Figure 2. Timing Diagram Rev. 0 | Page 5 of 28 ADF4150 ABSOLUTE MAXIMUM RATINGS TA = 25°C, unless otherwise noted. Table 3. Parameter AVDD to GND1 AVDD to DVDD VP to AVDD Digital I/O Voltage to GND1 Analog I/O Voltage to GND1 REFIN to GND1 Operating Temperature Range Storage Temperature Range Maximum Junction Temperature LFCSP θJA Thermal Impedance (Paddle-Soldered) Reflow Soldering Peak Temperature Time at Peak Temperature 1 Rating −0.3 V to +3.9 V −0.3 V to +0.3 V −0.3 V to +5.8 V −0.3 V to VDD + 0.3 V −0.3 V to VDD + 0.3 V −0.3 V to VDD + 0.3 V −40°C to +85°C −65°C to +125°C 150°C 27.3°C/W 260°C 40 sec 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 indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. TRANSISTOR COUNT 23380 (CMOS) and 809 (bipolar) ESD CAUTION GND = AGND = DGND = 0 V. Rev. 0 | Page 6 of 28 ADF4150 PIN CONFIGURATION AND FUNCTION DESCRIPTIONS RSET SDGND SDVDD MUXOUT LD REFIN CLK DATA LE CE SW VP 1 2 3 4 5 6 24 23 22 21 20 19 PIN 1 INDICATOR ADF4150 TOP VIEW (Not to Scale) 18 17 16 15 14 13 DVDD PDBRF AVDD2 RFOUT+ RFOUT− AGND Figure 3. Pin Configuration Table 4. Pin Function Descriptions Pin No. 1 2 3 4 5 6 7 8 9 10 11 12, 13 14 15 16 17 18 19 20 21 Mnemonic CLK DATA LE CE SW VP CPOUT CPGND AVDD1 RFIN+ RFIN− AGND RFOUT− RFOUT+ AVDD2 PDBRF DVDD REFIN LD MUXOUT Description Serial Clock Input. Data is clocked into the 32-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 three LSBs as 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 register is loaded into the register that is selected by the three LSBs. Chip Enable. A logic low on this pin powers down the device and puts the charge pump into three-state mode. Taking the pin high powers up the device depending on the status of the power-down bits. Fastlock Switch. Make a connection to this pin from the loop filter when using the fastlock mode. Charge Pump Power Supply. This pin should be greater than or equal to AVDD. In systems where AVDD is 3 V, it can be set to 5.5 V and used to drive a VCO with a tuning range of up to 5.5 V. Charge Pump Output. When enabled, this provides ±ICP to the external loop filter. The output of the loop filter is connected to VTUNE to drive the external VCO. Charge Pump Ground. This is the ground return pin for CPOUT. Analog Power Supply. This pin ranges from 3.0 V to 3.6 V. Decoupling capacitors to the analog ground plane are to be placed as close as possible to this pin. AVDD must have the same value as DVDD. Input to the RF Input. This small signal input is ac-coupled to the external VCO. Complementary Input to the RF Input. This point must be decoupled to the ground plane with a small bypass capacitor, typically 100 pF. Analog Ground. This is a ground return pin for AVDD1 and AVDD2. Complementary RF Output. The output level is programmable. The VCO fundamental output or a divided down version is available. RF Output. The output level is programmable. The VCO fundamental output or a divided down version is available. Analog Power Supply. This pin ranges from 3.0 V to 3.6 V. Decoupling capacitors to the analog ground plane are to be placed as close as possible to this pin. AVDD2 must have the same value as DVDD. RF Power-Down. A logic low on this pin mutes the RF outputs. This function is also software controllable. Digital Power Supply. This pin should be the same voltage as AVDD. Place decoupling capacitors to the ground plane as close as possible to this pin. Reference Input. This is a CMOS input with a nominal threshold of VDD/2 and a dc equivalent input resistance of 100 kΩ. This input can be driven from a TTL or CMOS crystal oscillator, or it can be ac-coupled. Lock Detect Output Pin. This pin outputs a logic high to indicate PLL lock; a logic low output indicates loss of PLL lock. Multiplexer Output. This multiplexer output allows either the lock detect, the scaled RF, or the scaled reference frequency to be accessed externally. Rev. 0 | Page 7 of 28 08226-003 NOTES 1. THE LFCSP HAS AN EXPOSED PADDLE THAT MUST BE CONNECTED TO GND. CPOUT CPGND AVDD1 RFIN+ RFIN– AGND 7 8 9 10 11 12 ADF4150 Pin No. 22 23 24 Mnemonic SDVDD SDGND RSET Description Power Supply Pin for the Digital Sigma-Delta (Σ-Δ) Modulator. This pin should be the same voltage as AVDD. Decoupling capacitors to the ground plane are to be placed as close as possible to this pin. Digital Σ-Δ Modulator Ground. Ground return path for the Σ-Δ modulator. Connecting a resistor between this pin and GND sets the charge pump output current. The nominal voltage bias at the RSET pin is 0.48 V. The relationship between ICP and RSET is I CP = 23.9 RSET 25 EP where: RSET = 5.1 kΩ. ICP = 5 mA. The exposed pad must be connected to GND. Rev. 0 | Page 8 of 28 ADF4150 TYPICAL PERFORMANCE CHARACTERISTICS 0 –5 –10 –15 –60 –80 POWER (dBm) –100 –20 –25 –30 –35 –40 –45 –50 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 FREQUENCY (GHz) +25°C +85°C –40°C 08226-042 POWER (dBc) –120 –140 –160 4.5 5.0 1k 10k 100k FREQUENCY (Hz) 1M 10M Figure 4. RF Input Sensitivity; RF Output Enabled; Output Divide-by-1 Selected 10 Figure 7. Integer-N Phase Noise and Spur Performance; Low Noise Mode; VCOOUT = 1750 MHz, REFIN = 100 MHz, PFD = 25 MHz, Loop Filter Bandwidth= 50 kHz –60 0 –80 –10 POWER (dBm) –20 POWER (dBc) –100 –120 –30 –140 –40 08226-043 0 1 2 3 FREQUENCY (MHz) 4 5 6 10M 100M FREQUENCY (Hz) 1G 10G Figure 5. RF Input Sensitivity; RF Output Disabled Figure 8. Fractional-N Phase Noise and Spur Performance; Low Noise Mode; VCOOUT = 1750 MHz, REFIN = 100 MHz, PFD = 25 MHz, Loop Filter Bandwidth= 15 kHz, Channel Spacing = 200 kHz. FRAC = 26, MOD = 125 –60 0 –5 –10 –80 –100 POWER (dBm) –15 –20 –25 –30 –35 –40 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 FREQUENCY (GHz) +25°C +85°C –40°C 08226-044 POWER (dBc) –120 –140 –160 10k 100k FREQUENCY (Hz) 1M 10M Figure 6. RF Sensitivity; RF Output Enabled (RF Dividers-by-2/-4/-8/-16 Enabled) Figure 9. Fractional-N Phase Noise and Spur Performance; Low Spur Mode; VCOOUT = 1750 MHz, REFIN = 100 MHz, PFD = 25 MHz, Loop Filter Bandwidth= 50 kHz, Channel Spacing = 200 kHz. FRAC = 26, MOD = 125 Rev. 0 | Page 9 of 28 08226-047 –180 1k 08226-046 –50 +25°C +85°C –40°C –160 –180 1M 08226-045 –180 ADF4150 –60 –60 –80 –80 –100 –100 POWER (dBc) –120 POWER (dBc) –120 –140 –140 –160 –160 1k 10k 100k FREQUENCY (Hz) 1M 10M 08226-038 10k 100k FREQUENCY (Hz) 1M 10M Figure 10. RF Output Phase Noise RF Dividers Used; Integer-N; Low Noise Mode; VCOOUT = 1750 MHz, REFIN = 100 MHz, PFD = 25 MHz, Loop Filter Bandwidth = 50 kHz Figure 12. RF Buffer Output Fractional-N Phase Noise and Spur Performance; Low Noise Mode; VCOOUT = 1750 MHz, REFIN = 100 MHz, PFD = 25 MHz, Loop Filter Bandwidth = 15 kHz, Channel Spacing = 200 kHz; FRAC = 1, MOD = 5; Output Divider = 2 –60 –60 –80 –80 –100 POWER (dBc) –100 POWER (dBc) –120 –120 –140 –140 –160 –160 08226-039 10k 100k FREQUENCY (Hz) 1M 10M 10k 100k FREQUENCY (Hz) 1M 10M Figure 11. RF Buffer Output Fractional-N Phase Noise and Spur Performance; Low Noise Mode; VCOOUT = 1750 MHz, REFIN = 100 MHz, PFD = 25 MHz, Loop Filter Bandwidth = 15 kHz, Channel Spacing = 200 kHz; FRAC = 1, MOD = 5; Output Divider = 1 Figure 13. RF Buffer Output Fractional-N Phase Noise and Spur Performance; Low Noise Mode; VCOOUT = 1750 MHz, REFIN = 100 MHz, PFD = 25 MHz, Loop Filter Bandwidth = 15 kHz, Channel Spacing = 200 kHz. FRAC = 1, MOD = 5. Output divider = 4 Rev. 0 | Page 10 of 28 08226-041 –180 1k –180 1k 08226-040 –180 –180 1k ADF4150 CIRCUIT DESCRIPTION REFERENCE INPUT SECTION The reference input stage is shown in Figure 14. 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 100k Ω SW2 REFIN NC SW1 SW3 NO 08226-010 RF N DIVIDER N = INT + FRAC/MOD TO PFD FROM VCO OUTPUT/ OUTPUT DIVIDERS N COUNTER THIRD ORDER FRACTIONAL INTERPOLATOR INT REG MOD REG FRAC VALUE 08226-011 NC TO R COUNTER BUFFER Figure 15. RF INT Divider INT N MODE If the FRAC = 0 and DB8 in Register 2 (LDF) is set to 1, the synthesizer operates in integer-N mode. The DB8 in Register 2 (LDF) should be set to 1 to get integer-N digital lock detect. Additionally, lower phase noise is possible if the anti-backlash pulse width is reduced to 3 ns. This mode is not valid for fractional-N applications. Figure 14. Reference Input Stage RF N DIVIDER The RF N divider allows a division ratio in the PLL feedback path. Division ratio is determined by INT, FRAC, and MOD values, which build up this divider. INT, FRAC, MOD, AND R COUNTER RELATIONSHIP The INT, FRAC, and MOD values, in conjunction with the R counter, make it possible to generate output frequencies that are spaced by fractions of the PFD frequency. See the RF Synthesizer—A Worked Example section for more information. The RF VCO frequency (RFOUT) equation is RFOUT = fPFD × (INT + (FRAC/MOD)) (1) where: RFOUT is the output frequency of external voltage controlled oscillator (VCO). INT is the preset divide ratio of the binary 16–bit counter (23 to 65535 for 4/5 prescaler, 75 to 65535 for 8/9 prescaler). MOD is the preset fractional modulus (2 to 4095). FRAC is the numerator of the fractional division (0 to MOD − 1). fPFD = REFIN × [(1 + D)/(R × (1 + T))] where: REFIN is the reference input frequency. D is the REFIN doubler bit. T is the REFIN divide-by-2 bit (0 or 1). R is the preset divide ratio of the binary 10-bit programmable reference counter (1 to 1023). (2) R COUNTER The 10–bit R counter allows the input reference frequency (REFIN) to be divided down to produce the reference clock to the PFD. Division ratios from 1 to 1023 are allowed. PHASE FREQUENCY DETECTOR (PFD) AND CHARGE PUMP The phase frequency detector (PFD) takes inputs from the R counter and N counter and produces an output proportional to the phase and frequency difference between them. Figure 16 is a simplified schematic of the phase frequency detector. The PFD includes a programmable delay element that sets the width of the antibacklash pulse, which can be either 6 ns (default, for fractional-N applications) or 3 ns (for integer-N mode). This pulse ensures there is no dead zone in the PFD transfer function, and gives a consistent reference spur level. HIGH D1 U1 +IN CLR1 Q1 UP DELAY U3 CHARGE PUMP CP HIGH CLR2 DOWN D2 Q2 08226-012 U2 –IN Figure 16. PFD Simplified Schematic Rev. 0 | Page 11 of 28 ADF4150 MUXOUT AND LOCK DETECT The output multiplexer on the ADF4150 allows the user to access various internal points on the chip. The state of MUXOUT is controlled by M3, M2, and M1 (for details, see Figure 22). Figure 17 shows the MUXOUT section in block diagram form. R COUNTER INPUT PROGRAM MODES Figure 20 through Figure 25 show how the program modes are to be set up in the ADF4150. A number of settings in the ADF4150 are double buffered. These include the modulus value, phase value, R counter value, reference doubler, reference divide-by-2, and current setting. This means that two events have to occur before the part uses a new value of any of the double-buffered settings. First, the new value is latched into the device by writing to the appropriate register. Second, a new write must be performed on Register R0. For example, any time the modulus value is updated, Register R0 must be written to, thus ensuring the modulus value is loaded correctly. Divider select in Register 4 (R4) is also double buffered, but only if DB13 of Register 2 (R2) is high. DVDD THREE-STATE-OUTPUT DVDD DGND R COUNTER OUTPUT N COUNTER OUTPUT MUX CONTROL MUXOUT ANALOG LOCK DETECT DIGITAL LOCK DETECT RESERVED 08226-013 OUTPUT STAGE DGND Figure 17. MUXOUT Schematic INPUT SHIFT REGISTERS The ADF4150 digital section includes a 10-bit RF R counter, a 16-bit RF N counter, a 12-bit FRAC counter, and a 12-bit modulus counter. Data is clocked into the 32-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 six latches on the rising edge of LE. The destination latch is determined by the state of the three control bits (C3, C2, and C1) in the shift register. These are the 3 LSBs, DB2, DB1, and DB0, as shown in Figure 2. The truth table for these bits is shown in Table 5. Figure 19 shows a summary of how the latches are programmed. Table 5. C3, C2, and C1 Truth Table C3 0 0 0 0 1 1 Control Bits C2 0 0 1 1 0 0 C1 0 1 0 1 0 1 Register Register 0 (R0) Register 1 (R1) Register 2 (R2) Register 3 (R3) Register 4 (R4) Register 5 (R5) The RFOUT+ and RFOUT− pins of the ADF4150 are connected to the collectors of an NPN differential pair driven by buffered outputs of the VCO, as shown in Figure 18. To allow the user to optimize the power dissipation vs. the output power requirements, the tail current of the differential pair is programmable by Bit D2 and Bit D1 in Register 4 (R4). Four current levels may be set. These levels give output power levels of −4 dBm, −1 dBm, +2 dBm, and +5 dBm, respectively, using a 50 Ω resistor to AVDD and ac coupling into a 50 Ω load. Alternatively, both outputs can be combined in a 1 + 1:1 transformer or a 180° microstrip coupler (see the Output Matching section). If the outputs are used individually, the optimum output stage consists of a shunt inductor to AVDD. Another feature of the ADF4150 is that the supply current to the RF output stage can be shut down until the part achieves lock as measured by the digital lock detect circuitry. This is enabled by the mute-till-lock detect (MTLD) bit in Register 4 (R4). RFOUT+ RFOUT – VCO BUFFER/ DIVIDE-BY-1/ -2/-4/-8/-16 Figure 18. Output Stage Rev. 0 | Page 12 of 28 08226-014 ADF4150 REGISTER MAPS REGISTER 0 RESERVED 16-BIT INTEGER VALUE (INT) 12-BIT FRACTIONAL VALUE (FRAC) CONTROL BITS DB2 DB1 DB0 DB31 DB30 DB29 DB28 DB27 DB26 DB25 DB24 DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 0 N16 N15 N14 N13 N12 N11 N10 N9 N8 N7 N6 N5 N4 N3 N2 N1 F12 F11 F10 F9 F8 F7 F6 F5 F4 F3 F2 F1 C3(0) C2(0) C1(0) REGISTER 1 PRESCALER RESERVED 12-BIT PHASE VALUE (PHASE) DBR1 12-BIT MODULUS VALUE (MOD) DBR 1 CONTROL BITS DB2 DB1 DB0 DB31 DB30 DB29 DB28 DB27 DB26 DB25 DB24 DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 0 0 0 0 PR1 P12 P11 P10 P9 P8 P7 P6 P5 P4 P3 P2 P1 M12 M11 M10 M9 M8 M7 M6 M5 M4 M3 M2 M1 C3(0) C2(0) C1(1) REGISTER 2 REFERENCE DOUBLER DBR 1 DBR 1 POWER-DOWN DOUBLE BUFF RESERVED RDIV2 LDF LDP MUXOUT 10-BIT R COUNTER DBR 1 CHARGE PUMP CURRENT SETTING PD POLARITY COUNTER RESET LOW NOISE AND LOW SPUR MODES CP THREESTATE DBR 1 CONTROL BITS DB2 DB1 DB0 DB31 DB30 DB29 DB28 DB27 DB26 DB25 DB24 DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 0 L2 L1 M3 M2 M1 RD2 RD1 R10 R9 R8 R7 R6 R5 R4 R3 R2 R1 D1 CP4 CP3 CP2 CP1 U6 U5 U4 U3 U2 U1 C3(0) C2(1) C1(0) REGISTER 3 RESERVED CHARGE CANCEL CSR ABP RESERVED RESERVED CLK DIV MODE 12-BIT CLOCK DIVIDER VALUE CONTROL BITS DB2 DB1 DB0 DB31 DB30 DB29 DB28 DB27 DB26 DB25 DB24 DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 0 0 0 0 0 0 0 0 0 F3 F2 0 0 F1 0 C2 C1 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 C3(0) C2(1) C1(1) REGISTER 4 DBB 2 DIVIDER SELECT MTLD RF OUTPUT ENABLE FEEDBACK SELECT RESERVED RESERVED RESERVED OUTPUT POWER CONTROL BITS DB2 DB1 DB0 DB31 DB30 DB29 DB28 DB27 DB26 DB25 DB24 DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 0 0 0 0 0 0 0 0 D13 D12 D11 D10 BS8 BS7 BS6 BS5 BS4 BS3 BS2 BS1 D9 D8 D7 D6 D5 D4 D3 D2 D1 C3(1) C2(0) C1(0) REGISTER 5 RESERVED LD PIN MODE RESERVED RESERVED RESERVED CONTROL BITS DB2 DB1 DB0 DB31 DB30 DB29 DB28 DB27 DB26 DB25 DB24 DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 0 0 0 0 0 0 0 0 D15 D14 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 C3(1) C2(0) C1(1) 08226-015 1 DBR 2 DBB = DOUBLE BUFFERED REGISTER—BUFFERED BY THE WRITE TO REGISTER 0. = DOUBLE BUFFERED BITS—BUFFERED BY THE WRITE TO REGISTER 0, IF AND ONLY IF DB13 OF REGISTER 2 IS HIGH. Figure 19. Register Summary Rev. 0 | Page 13 of 28 ADF4150 RESERVED 16-BIT INTEGER VALUE (INT) 12-BIT FRACTIONAL VALUE (FRAC) DB7 DB6 F5 F4 DB5 DB4 F3 F2 DB3 F1 CONTROL BITS DB2 DB1 DB0 DB31 DB30 DB29 DB28 DB27 DB26 DB25 DB24 DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 0 N16 N15 N14 N13 N12 N11 N10 N9 N8 N7 N6 N5 N4 N3 N2 N1 F12 F11 F10 F9 F8 F7 F6 C3(0) C2(0) C1(0) N16 0 0 0 . 0 0 0 . 1 1 1 N15 0 0 0 . 0 0 0 . 1 1 1 ... ... ... ... ... ... ... ... ... ... ... ... N5 0 0 0 . 1 1 1 . 1 1 1 N4 0 0 0 . 0 0 1 . 1 1 1 N3 0 0 0 . 1 1 0 . 1 1 1 N2 0 0 1 . 1 1 0 . 0 1 1 N1 0 1 0 . 0 1 0 . 1 0 1 INTEGER VALUE (INT) NOT ALLOWED NOT ALLOWED NOT ALLOWED ... NOT ALLOWED 23 24 ... 65533 65534 65535 F12 0 0 0 0 . . . 1 1 1 1 F11 0 0 0 0 . . . 1 1 1 1 .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... ......... F2 0 0 1 1 . . . 0 0 1 1 F1 0 1 0 1 . . . 0 1 0 1 FRACTIONAL VALUE (FRAC) 0 1 2 3 . . . 4092 4093 4094 4095 08226-016 INTmin = 75 with prescaler = 8/9 Figure 20. Register 0 (R0) PRESCALER RESERVED 12-BIT PHASE VALUE (PHASE) DBR 12-BIT MODULUS VALUE (MOD) DB7 DB6 M5 M4 DBR DB5 DB4 M3 M2 DB3 M1 CONTROL BITS DB2 DB1 DB0 DB31 DB30 DB29 DB28 DB27 DB26 DB25 DB24 DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 0 0 0 0 PR1 P12 P11 P10 P9 P8 P7 P6 P5 P4 P3 P2 P1 M12 M11 M10 M9 M8 M7 M6 C3(0) C2(0) C1(1) P1 0 1 PRESCALER 4/5 8/9 P12 0 0 0 0 . . . 1 1 1 1 P11 0 0 0 0 . . . 1 1 1 1 .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... P2 0 0 1 1 . . . 0 0 1 1 P1 0 1 0 1 . . . 0 1 0 1 PHASE VALUE (PHASE) 0 1 (RECOMMENDED) 2 3 . . . 4092 4093 4094 4095 M12 0 0 . . . 1 1 1 1 M11 0 0 . . . 1 1 1 1 .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... M2 1 1 . . . 0 0 1 1 M1 0 1 . . . 0 1 0 1 INTERPOLATOR MODULUS (MOD) 2 3 . . . 4092 4093 4094 4095 Figure 21. Register 1 (R1) Rev. 0 | Page 14 of 28 08226-017 ADF4150 REFERENCE DOUBLER DBR DOUBLE BUFF POWER-DOWN RESERVED DBR CP THREESTATE LOW NOISE AND LOW SPUR MODES CHARGE PUMP CURRENT SETTING PD POLARITY RDIV2 LDF COUNTER RESET MUXOUT 10-BIT R COUNTER DBR CONTROL BITS DB2 DB1 DB0 DB31 DB30 DB29 DB28 DB27 DB26 DB25 DB24 DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 0 L2 L1 M3 M2 M1 RD2 RD1 R10 R9 R8 R7 R6 R5 R4 R3 R2 R1 D1 CP4 CP3 CP2 CP1 U6 U5 U4 U3 U2 U1 LDP C3(0) C2(1) C1(0) L1 0 0 1 1 L2 0 1 0 1 NOISE MODE LOW NOISE MODE RESERVED RESERVED LOW SPUR MODE RD2 0 1 REFERENCE DOUBLER DISABLED ENABLED RD1 0 1 REFERENCE DIVIDE BY 2 DISABLED ENABLED CP4 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 D1 0 1 DOUBLE BUFFER R4 DB22:DB20 DISABLED ENABLED ICP (mA) 4.7kΩ 0.31 0.63 0.94 1.25 1.56 1.88 2.19 2.50 2.81 3.13 3.44 3.75 4.06 4.38 4.69 5.00 U6 0 1 LDF FRAC-N INT-N U1 0 1 U2 0 1 U3 0 1 COUNTER RESET DISABLED ENABLED CP3 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 CP2 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 CP1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 U5 0 1 LDP 10ns 6ns CP THREE-STATE DISABLED ENABLED R10 0 0 . . . 1 1 1 1 R9 0 0 . . . 1 1 1 1 .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... R2 0 1 . . . 0 0 1 1 R1 1 0 . . . 0 1 0 1 R DIVIDER (R) 1 2 . . . 1020 1021 1022 1023 U4 0 1 PD POLARITY NEGATIVE POSITIVE POWER-DOWN DISABLED ENABLED M3 0 0 0 0 1 1 1 1 M2 0 0 1 1 0 0 1 1 M1 0 1 0 1 0 1 0 1 OUTPUT THREE-STATE OUTPUT DVDD DGND R DIVIDER OUTPUT N DIVIDER OUTPUT DIGITAL LOCK DETECT RESERVED ANALOG LOCK DETECT Figure 22. Register 2 (R2) Rev. 0 | Page 15 of 28 08226-018 ADF4150 RESERVED RESERVED CHARGE CANCEL CLK DIV MODE ABP CSR RESERVED 12-BIT CLOCK DIVIDER VALUE DB7 DB6 D5 D4 DB5 DB4 D3 D2 DB3 D1 CONTROL BITS DB2 DB1 DB0 DB31 DB30 DB29 DB28 DB27 DB26 DB25 DB24 DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 0 0 0 0 0 0 0 0 0 F3 F2 0 0 F1 0 C2 C1 D12 D11 D10 D9 D8 D7 D6 C3(0) C2(1) C1(1) F1 0 1 CYCLE SLIP REDUCTION DISABLED ENABLED D12 0 0 0 0 . . . 1 1 1 1 D11 0 0 0 0 . . . 1 1 1 1 .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... D2 0 0 1 1 . . . 0 0 1 1 D1 0 1 0 1 . . . 0 1 0 1 CLOCK DIVIDER VALUE 0 1 2 3 . . . 4092 4093 4094 4095 C2 0 0 1 1 C1 0 1 0 1 CLOCK DIVIDER MODE CLOCK DIVIDER OFF FAST LOCK ENABLE RESYNC ENABLE RESERVED F2 0 1 CHARGE CANCELLATION DISABLED ENABLED F3 0 1 ANTIBACKLASH PULSE WIDTH 6ns (FRAC-N) 3ns (INT_N) 08226-019 Figure 23. Register 3 (R3) DBB 2 DIVIDER SELECT RF OUTPUT ENABLE FEEDBACK SELECT MTLD RESERVED RESERVED RESERVED OUTPUT POWER CONTROL BITS DB2 DB1 DB0 DB31 DB30 DB29 DB28 DB27 DB26 DB25 DB24 DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 0 0 0 0 0 0 0 0 D13 D12 D11 D10 BS8 BS7 BS6 BS5 BS4 BS3 BS2 BS1 D9 D8 D7 D6 D5 D4 D3 D2 D1 C3(1) C2(0) C1(0) FEEDBACK D13 SELECT 0 1 DIVIDED FUNDAMENTAL MUTE TILL LOCK DETECT MUTE DISABLED MUTE ENABLED D3 0 1 D2 0 0 1 D10 0 1 0 1 0 RF DIVIDER SELECT ÷1 ÷2 ÷4 ÷8 ÷16 1 RF OUT D1 0 1 0 1 OUTPUT POWER –4 –1 +2 +5 D12 0 0 0 0 1 D11 0 0 1 1 0 D8 0 1 DISABLED 08226-020 ENABLED Figure 24. Register 4 (R4) Rev. 0 | Page 16 of 28 ADF4150 LD PIN MODE RESERVED RESERVED RESERVED RESERVED DB3 0 CONTROL BITS DB2 DB1 DB0 DB31 DB30 DB29 DB28 DB27 DB26 DB25 DB24 DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 0 0 0 0 0 0 0 0 D15 D14 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 C3(1) C2(0) C1(1) D1 5 0 0 1 1 D1 4 0 1 0 1 LOCK DETECT PIN OPERATION LOW DIGITAL LOCK DETECT LOW HIGH 08226-021 Figure 25. Register 5 (R5) Rev. 0 | Page 17 of 28 ADF4150 REGISTER 0 Control Bits With Bits[C3:C1] set to 0, 0, 0, Register 0 is programmed. Figure 20 shows the input data format for programming this register. 12-Bit Phase Value (Phase) These bits control what is loaded as the phase word. The word must be less than the MOD value programmed in Register 1. The word is used to program the RF output phase from 0° to 360° with a resolution of 360°/MOD. See the Phase Resync section for more information. In most applications, the phase relationship between the RF signal and the reference is not important. In such applications, the PHASE value can be used to optimize the fractional and subfractional spur levels. See the Spur Consistency and Fractional Spur Optimization section for more information. If neither the PHASE resync nor the spurious optimization functions are being used, it is recommended that the PHASE word be set to 1. 16-Bit Integer Value (INT) These 16 bits set the INT value, which determines the integer part of the feedback division factor. They are used in Equation 1 (see the INT, FRAC, MOD, and R Counter Relationship section). All integer values from 23 to 65,535 are allowed for 4/5 prescaler. For 8/9 prescaler, the minimum integer value is 75. 12-Bit Fractional Value(FRAC) The 12 FRAC bits set the numerator of the fraction that is input to the Σ-Δ modulator. This, along with INT, specifies the new frequency channel that the synthesizer locks to, as shown in the RF Synthesizer—A Worked Example section. FRAC values from 0 to MOD − 1 cover channels over a frequency range equal to the PFD reference frequency. 12-Bit Modulus Value (MOD) This programmable register sets the fractional modulus. This is the ratio of the PFD frequency to the channel step resolution on the RF output. See the RF Synthesizer—A Worked Example section for more information. REGISTER 1 Control Bits With Bits[C3:C1] set to 0, 0, 1, Register 1 is programmed. Figure 21 shows the input data format for programming this register. REGISTER 2 Control Bits With Bits[C3:C1] set to 0, 1, 0, Register 2 is programmed. Figure 22 shows the input data format for programming this register. Prescaler Value The dual modulus prescaler (P/P + 1), along with the INT, FRAC, and MOD counters, determines the overall division ratio from the VCO output to the PFD input. Operating at CML levels, it takes the clock from the VCO output and divides it down for the counters. It is based on a synchronous 4/5 core. When set to 4/5, the maximum RF frequency allowed is 3 GHz. Therefore, when operating the ADF4150 above 3 GHz, this must be set to 8/9. The prescaler limits the INT value, where: P = 4/5, NMIN = 23 P = 8/9, NMIN = 75 In the ADF4150, P1 in Register 1 sets the prescaler values. Low Noise and Spur Modes The noise modes on the ADF4150 are controlled by DB30 and DB29 in Register 2 (see Figure 22). The noise modes allow the user to optimize a design either for improved spurious performance or for improved phase noise performance. When the lowest spur setting is chosen, dither is enabled. This randomizes the fractional quantization noise so it resembles white noise rather than spurious noise. As a result, the part is optimized for improved spurious performance. This operation would normally be used when the PLL closed-loop bandwidth is wide, for fast-locking applications. (Wide loop bandwidth is seen as a loop bandwidth greater than 1/10 of the RFOUT channel step resolution (fRES)). A wide loop filter does not attenuate the spurs to the same level as a narrow loop bandwidth. For best noise performance, use the lowest noise setting option. As well as disabling the dither, it also ensures that the charge pump is operating in an optimum region for noise performance. This setting is extremely useful where a narrow loop filter bandwidth is available. The synthesizer ensures extremely low noise and the filter attenuates the spurs. The typical performance characteristics give the user an idea of the trade-off in a typical W-CDMA setup for the different noise and spur settings. Rev. 0 | Page 18 of 28 ADF4150 MUXOUT The on-chip multiplexer is controlled by Bits[DB28:DB26] (see Figure 22). Lock Detect Precision (LDP) When DB7 is set to 0, the fractional-N digital lock detect is activated. In this case after setting DB7 to 0, 40 consecutive PFD cycles of 10 ns must occur before digital lock detect is set. When DB7 is programmed to 1, 40 consecutive reference cycles of 6 ns must occur before digital lock detect goes high. Setting DB8 to 1 causes the activation of the integer-N digital lock detect. In this case, after setting DB7 to 0, 5 consecutive cycles of 10 ns must occur before digital lock detect is set. When DB7 is set to 1, five consecutive cycles of 6 ns must occur. Reference Doubler Setting DB25 to 0 feeds the REFIN signal directly to the 10-bit R counter, disabling the doubler. Setting this bit to 1 multiplies the REFIN frequency by a factor of 2 before feeding into the 10-bit R counter. When the doubler is disabled, the REFIN falling edge is the active edge at the PFD input to the fractional synthesizer. When the doubler is enabled, both the rising and falling edges of REFIN become active edges at the PFD input. When the doubler is enabled and the lowest spur mode is chosen, the in-band phase noise performance is sensitive to the REFIN duty cycle. The phase noise degradation can be as much as 5 dB for the REFIN duty cycles outside a 45% to 55% range. The phase noise is insensitive to the REFIN duty cycle in the lowest noise mode. The phase noise is insensitive to the REFIN duty cycle when the doubler is disabled. The maximum allowable REFIN frequency when the doubler is enabled is 30 MHz. Phase Detector Polarity DB6 sets the phase detector polarity. When a passive loop filter, or noninverting active loop filter is used, set this bit to 1. If an active filter with an inverting characteristic is used, this bit should be set to 0. Power-Down (PD) DB5 provides the programmable power-down mode. Setting this bit to 1 performs a power-down. Setting this bit to 0 returns the synthesizer to normal operation. When in software power-down mode, the part retains all information in its registers. Only if the supply voltages are removed are the register contents lost. When a power-down is activated, the following events occur: • • • • • The synthesizer 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 RFOUT buffers are disabled. The input register remains active and capable of loading and latching data. RDIV2 Setting the DB24 bit to 1 inserts a divide-by-2 toggle flip-flop between the R counter and PFD, which extends the maximum REFIN input rate. This function allows a 50% duty cycle signal to appear at the PFD input, which is necessary for cycle slip reduction. 10-Bit R Counter The 10-bit R counter allows the input reference frequency (REFIN) to be divided down to produce the reference clock to the PFD. Division ratios from 1 to 1023 are allowed. Double Buffer DB13 enables or disables double buffering of Bits[DB22:DB20] in Register 4. The Divider Select section explains how double buffering works. Charge Pump (CP) Three-State DB4 puts the charge pump into three-state mode when programmed to 1. It should be set to 0 for normal operation. Counter Reset DB3 is the R counter and N counter reset bit for the ADF4150. When this bit is 1, the RF synthesizer N counter and R counter are held in reset. For normal operation, this bit should be set to 0. Current Setting Bits[DB12:DB9] set the charge pump current setting. This should be set to the charge pump current that the loop filter is designed with (see Figure 22). LDF Setting DB8 to 1 enables integer-N digital lock detect, when the FRAC part of the divider is zero; setting DB8 to 0 enables fractional-N digital lock detect. Rev. 0 | Page 19 of 28 ADF4150 REGISTER 3 Control Bits With Bits[C3:C1] set to 0, 1, 1, Register 3 is programmed. Figure 23 shows the input data format for programming this register. REGISTER 4 Control Bits With Bits[C3: C1] set to 1, 0, 0, Register 4 is programmed. Figure 24 shows the input data format for programming this register. Antibacklash Pulse Width Setting DB22 to 0 sets the PFD antibacklash pulse width to 6 ns. This is the recommended mode for fractional-N use. By setting this bit to 1, the 3 ns pulse width is used and results in a phase noise and spur improvement in integer-N operation. For fractional-N mode it is not recommended to use this smaller setting. Feedback Select DB23 selects the feedback from VCO output to the N-counter. When this bit is set to 1, the signal is taken from the VCO directly. When this bit is set to 0, it is taken from the output of the output dividers. The dividers enable covering of the wide frequency band (137.5 MHz to 4.4 GHz). When the divider is enabled and the feedback signal is taken from the output, the RF output signals of two separately configured PLLs are in phase. This is useful in some applications where the positive interference of signals is required to increase the power. Charge Cancellation Mode Pulse Width Setting DB21 to 1 enables charge pump charge cancellation. This has the effect of reducing PFD spurs in integer-N mode. In fractional-N mode, this bit should not be used and the relevant result in a phase noise and spur improvement. For fractional-N mode, it is not recommended to use this smaller setting. Divider Select Bits[DB22:DB20] select the value of the output divider (see Figure 24). Mute-Till-Lock Detect If DB10 is set to 1, the supply current to the RF output stage is shut down until the part achieves lock as measured by the digital lock detect circuitry. Cycle Slip Reduction (CSR) Enable Setting DB18 to 1 enables cycle slip reduction. This is a method for improving lock times. Note that the signal at the phase frequency detector (PFD) must have a 50% duty cycle for cycle slip reduction to work. The charge pump current setting must also be set to a minimum. See the Cycle Slip Reduction for Faster Lock Times section for more information. RF Output Enable DB5 enables or disables primary RF output, depending on the chosen value. Clock Divider Mode Bits[DB16:DB15] must be set to 1, 0 to activate PHASE resync or 0, 1 to activate fast lock. Setting Bits[DB16:DB15] to 0, 0 disables the clock divider. See Figure 23. Output Power DB4 and DB3 set the value of the primary RF output power level (see Figure 24). REGISTER 5 Control Bits With Bits[C3:C1] set to 1, 0, 1, Register 5 is programmed. Figure 25 shows the input data form for programming this register. 12-Bit Clock Divider Value The 12-bit clock divider value sets the timeout counter for activation of PHASE resync. See the Phase Resync section for more information. It also sets the timeout counter for fast lock. See the Fast Lock Timer and Register Sequences section for more information. Lock Detect PIN Operation Bits[DB23:DB22] set the operation of the lock detect pin (see Figure 25). INITIALIZATION SEQUENCE The following sequence of registers is the correct sequence for initial power up of the ADF4150 after the correct application of voltages to the supply pins: • • • • • • Register 5 Register 4 Register 3 Register 2 Register 1 Register 0 Rev. 0 | Page 20 of 28 ADF4150 RF SYNTHESIZER—A WORKED EXAMPLE The following is an example how to program the ADF4150 synthesizer: RFOUT = [INT + (FRAC/MOD)] × [fPFD]/RF Divider (3) MODULUS The choice of modulus (MOD) depends on the reference signal (REFIN) available and the channel resolution (fRES) required at the RF output. For example, a GSM system with 13 MHz REFIN sets the modulus to 65. This means the RF output resolution (fRES) is the 200 kHz (13 MHz/65) necessary for GSM. With dither off, the fractional spur interval depends on the modulus values chosen (see Table 6). where: RFOUT is the RF frequency output. INT is the integer division factor. FRAC is the fractionality. MOD is the modulus. RF Divider is the output divider that divides down the VCO frequency. fPFD = REFIN × [(1 + D)/(R × (1 + T))] where: REFIN is the reference frequency input. D is the RF REFIN doubler bit. T is the reference divide-by-2 bit (0 or 1). R is the RF reference division factor. For example, in a UMTS system, where 2112.6 MHz RF frequency output (RFOUT) is required, a 10 MHz reference frequency input (REFIN) is available, and a 200 kHz channel resolution (fRESOUT) is required, on the RF output. A 2.1 GHz VCO would be suitable, but a 4.2 GHz VCO would also be suitable. In the second case, the RF divider of 2 should be used (VCO frequency = 4225.2 MHz, RFOUT = VCO frequency/RF divider = 4225.2 MHz/2 = 2112.6 MHz). It is also important where the loop is closed. In this example, the loop is closed as depicted in Figure 26 (from the out divider). fPFD PFD VCO ÷2 RFOUT REFERENCE DOUBLER AND REFERENCE DIVIDER The reference doubler on-chip allows the input reference signal to be doubled. This is useful for increasing the PFD comparison frequency. Making the PFD frequency higher improves the noise performance of the system. Doubling the PFD frequency usually improves noise performance by 3 dB. It is important to note that the PFD cannot operate above 32 MHz due to a limitation in the speed of the Σ-Δ circuit of the N-divider. The reference divide-by-2 divides the reference signal by 2, resulting in a 50% duty cycle PFD frequency. This is necessary for the correct operation of the cycle slip reduction (CSR) function. See the Cycle Slip Reduction for Faster Lock Times section for more information. (4) 12-BIT PROGRAMMABLE MODULUS Unlike most other fractional-N PLLs, the ADF4150 allows the user to program the modulus over a 12-bit range. This means the user can set up the part in many different configurations for the application, when combined with the reference doubler and the 10-bit R counter. For example, consider an application that requires 1.75 GHz RF and 200 kHz channel step resolution. The system has a 13 MHz reference signal. One possible setup is feeding the 13 MHz directly to the PFD and programming the modulus to divide by 65. This results in the required 200 kHz resolution. Another possible setup is using the reference doubler to create 26 MHz from the 13 MHz input signal. The 26 MHz is then fed into the PFD programming the modulus to divide by 130. This also results in 200 kHz resolution and offers superior phase noise performance over the previous setup. The programmable modulus is also very useful for multistandard applications. If a dual-mode phone requires PDC and GSM 1800 standards, the programmable modulus is a great benefit. PDC requires 25 kHz channel step resolution, whereas GSM 1800 requires 200 kHz channel step resolution. N DIVIDER Figure 26. Loop Closed Before Output Divider A channel resolution (fRESOUT) of 200 kHz is required at the output of the RF divider. Therefore, channel resolution at the output of the VCO (fRES) is to be twice the fRESOUT, that is, 400 kHz. MOD = REFIN/fRES MOD = 10 MHz/400 kHz = 25 From Equation 4 fPFD = [10 MHz × (1 + 0)/1] = 10 MHz 2112.6 MHz = 10 MHz × (INT + FRAC/25)/2 where: INT = 422 FRAC = 13 (5) (6) 08226-022 Rev. 0 | Page 21 of 28 ADF4150 A 13 MHz reference signal can be fed directly to the PFD, and the modulus can be programmed to 520 when in PDC mode (13 MHz/520 = 25 kHz). The modulus needs to be reprogrammed to 65 for GSM 1800 operation (13 MHz/65 = 200 kHz). It is important that the PFD frequency remain constant (13 MHz). This allows the user to design one loop filter for both setups without running into stability issues. It is important to remember that the ratio of the RF frequency to the PFD frequency principally affects the loop filter design, not the actual channel spacing. If the phase error increases again to a point where another cycle slip is likely, the ADF4150 turns on another charge pump cell. This continues until the ADF4150 detects the VCO frequency has gone past the desired frequency. The extra charge pump cells are turned off one by one until all the extra charge pump cells have been disabled and the frequency is settled with the original loop filter bandwidth. Up to seven extra charge pump cells can be turned on. In most applications, it is enough to eliminate cycle slips altogether, giving much faster lock times. Setting Bit DB18 in Register 3 to 1 enables cycle slip reduction. Note that the PFD requires a 45% to 55% duty cycle for CSR to operate correctly. CYCLE SLIP REDUCTION FOR FASTER LOCK TIMES As outlined in the Low Noise and Spur Mode section, the ADF4150 contains a number of features that allow optimization for noise performance. However, in fast locking applications, the loop bandwidth generally needs to be wide, and therefore, the filter does not provide much attenuation of the spurs. If the cycle slip reduction feature is enabled, the narrow loop bandwidth is maintained for spur attenuation but faster lock times are still possible. SPURIOUS OPTIMIZATION AND FAST LOCK Narrow loop bandwidths can filter unwanted spurious signals, but these usually have a long lock time. A wider loop bandwidth achieves faster lock times, but a wider loop bandwidth may lead to increased spurious signals inside the loop bandwidth. The fast lock feature can achieve the same fast lock time as the wider bandwidth, but with the advantage of a narrow final loop bandwidth to keep spurs low. Cycle Slips Cycle slips occur in integer-N/fractional-N synthesizers when the loop bandwidth is narrow compared to the PFD frequency. The phase error at the PFD inputs accumulates too fast for the PLL to correct, and the charge pump temporarily pumps in the wrong direction. This slows down the lock time dramatically. The ADF4150 contains a cycle slip reduction feature that extends the linear range of the PFD, allowing faster lock times without modifications to the loop filter circuitry. When the circuitry detects that a cycle slip is about to occur, it turns on an extra charge pump current cell. This outputs a constant current to the loop filter, or removes a constant current from the loop filter (depending on whether the VCO tuning voltage needs to increase or decrease to acquire the new frequency). The effect is that the linear range of the PFD is increased. Loop stability is maintained because the current is constant and is not a pulsed current. FAST LOCK TIMER AND REGISTER SEQUENCES If the fast lock mode is used, a timer value is to be loaded into the PLL to determine the duration of the wide bandwidth mode. When Bits[DB16:DB15] in Register 3 are set to 0, 1 (fast lock enable), the timer value is loaded by the 12-bit clock divider value. The following sequence must be programmed to use fast lock: 1. 2. Initialization sequence (see the Initialization Sequence section); occurs only once after powering up the part. Load Register 3 by setting Bits[DB16:DB15] to 0, 1 and the chosen fast lock timer value [DB14:DB3]. Note that the duration the PLL remains in wide bandwidth is equal to the fast lock timer/fPFD. Rev. 0 | Page 22 of 28 ADF4150 FAST LOCK—AN EXAMPLE If a PLL has a reference frequency of 13 MHz, fPFD of 13 MHz and a required lock time of 50 µs, the PLL is set to wide bandwidth for 40 µs. This example assumes a modulus of 65 for channel spacing of 200 kHz. If the time period set for the wide bandwidth is 40 µs, then Fast Lock Timer Value = Time In Wide Bandwidth × fPFD/MOD Fast Lock Timer Value = 40 µs × 13 MHz/65 = 8 Therefore, 8 must be loaded into the clock divider value in Register 3 in Step 1 of the sequence described in the Fast Lock Timer and Register Sequences section. SPUR MECHANISMS This section describes the three different spur mechanisms that arise with a fractional-N synthesizer and how to minimize them in the ADF4150. Fractional Spurs The fractional interpolator in the ADF4150 is a third-order Σ-Δ modulator (SDM) with a modulus (MOD) that is programmable to any integer value from 2 to 4095. In low spur mode (dither enabled), the minimum allowable value of MOD is 50. The SDM is clocked at the PFD reference rate (fPFD) that allows PLL output frequencies to be synthesized at a channel step resolution of fPFD/MOD. In low noise mode (dither off), the quantization noise from the Σ-Δ modulator appears as fractional spurs. The interval between spurs is fPFD/L, where L is the repeat length of the code sequence in the digital Σ-Δ modulator. For the third-order modulator used in the ADF4150, the repeat length depends on the value of MOD, as listed in Table 6. Table 6. Fractional Spurs with Dither Off Condition (Dither Off) If MOD is divisible by 2 but not 3 If MOD is divisible by 3 but not 2 If MOD is divisible by 6 Otherwise Repeat Length 2 × MOD 3 × MOD 6 × MOD MOD Spur Interval Channel step/2 Channel step/3 Channel step/6 Channel step FAST LOCK—LOOP FILTER TOPOLOGY To use fast lock mode, the damping resistor in the loop filter is reduced to ¼ of its value while in wide bandwidth mode. To achieve the wider loop filter bandwidth, the charge pump current increases by a factor of 16. To maintain loop stability, the damping resistor must be reduced a factor of ¼. To enable fast lock, the SW pin is shorted to the GND pin by settings Bits[DB16:DB15] in Register 3 to 0, 1. The following two topologies are available: • • The damping resistor (R1) is divided into two values (R1 and R1A) that have a ratio of 1:3 (see Figure 27). An extra resistor (R1A) is connected directly from SW, as shown in Figure 28. The extra resistor is calculated such that the parallel combination of an extra resistor and the damping resistor (R1) is reduced to ¼ of the original value of R1 (see Figure 28). ADF4150 CP C1 C2 R1 SW R1A 08226-023 R2 VCO C3 In low spur mode (dither on), the repeat length is extended to 221 cycles, regardless of the value of MOD, which makes the quantization error spectrum look like broadband noise. This may degrade the in-band phase noise at the PLL output by as much as 10 dB. For lowest noise, dither off is a better choice, particularly when the final loop bandwidth is low enough to attenuate even the lowest frequency fractional spur. Integer Boundary Spurs Another mechanism for fractional spur creation is the interactions between the RF VCO frequency and the reference frequency. When these frequencies are not integer related (the point of a fractional-N synthesizer) spur sidebands appear on the VCO output spectrum at an offset frequency that corresponds to the beat note or difference frequency between an integer multiple of the reference and the VCO frequency. These spurs are attenuated by the loop filter and are more noticeable on channels close to integer multiples of the reference where the difference frequency can be inside the loop bandwidth, therefore the name integer boundary spurs. Figure 27. Fast Lock Loop Filter Topology—Topology 1 ADF4150 CP C1 C2 R2 VCO C3 R1A SW R1 Figure 28. Fast Lock Loop Filter Topology—Topology 2 08226-024 Rev. 0 | Page 23 of 28 ADF4150 Reference Spurs Reference spurs are generally not a problem in fractional-N synthesizers because the reference offset is far outside the loop bandwidth. However, any reference feedthrough mechanism that bypasses the loop can cause a problem. Feedthrough of low levels of on-chip reference switching noise, through the RFIN pin back to the VCO, can result in reference spur levels as high as −90 dBc. PCB layout needs to ensure adequate isolation between VCO traces and the input reference to avoid a possible feedthrough path on the board. Phase resync is enabled by setting Bit DB16, Bit DB15 in Register 3 to 1, 0. When PHASE resync is enabled, an internal timer generates sync signals at intervals of tSYNC given by the following formula: tSYNC = CLK_DIV_VALUE × MOD × tPFD where: tPFD is the PFD reference period. CLK_DIV_VALUE is the decimal value programmed in Bits[DB14:DB3] of Register 3 and can be any integer in the range of 1 to 4095. MOD is the modulus value programmed in Bits[DB14:DB3] of Register 1 (R1). When a new frequency is programmed, the second sync pulse after the LE rising edge is used to resynchronize the output phase to the reference. The tSYNC time is to be programmed to a value that is at least as long as the worst-case lock time. This guarantees that the PHASE resync occurs after the last cycle slip in the PLL settling transient. In the example shown in Figure 29, the PFD reference is 25 MHz and MOD is 125 for a 200 kHz channel spacing. tSYNC is set to 400 µs by programming CLK_DIV_VALUE to 80. LE SPUR CONSISTENCY AND FRACTIONAL SPUR OPTIMIZATION With dither off, the fractional spur pattern due to the quantization noise of the SDM also depends on the particular phase word with which the modulator is seeded. The phase word can be varied to optimize the fractional and subfractional spur levels on any particular frequency. Thus, a look-up table of phase values corresponding to each frequency can be constructed for use when programming the ADF4150. If a look-up table is not used, keep the phase word at a constant value to ensure consistent spur levels on any particular frequency. PHASE RESYNC The output of a fractional-N PLL can settle to any one of the MOD phase offsets with respect to the input reference, where MOD is the fractional modulus. The phase resync feature in the ADF4150 produces a consistent output phase offset with respect to the input reference. This is necessary in applications where the output phase and frequency are important, such as digital beam forming. See the Phase Programmability section for how to program a specific RF output phase when using phase resync. tSYNC SYNC (INTERNAL) LAST CYCLE SLIP FREQUENCY PLL SETTLES TO INCORRECT PHASE PLL SETTLES TO CORRECT PHASE AFTER RESYNC PHASE –100 0 100 200 300 400 500 600 TIME (µs) 700 800 900 1000 Figure 29. Phase Resync Example Phase Programmability The phase word in Register 1 controls the RF output phase. As this word is swept from 0 to MOD, the RF output phase sweeps over a 360° range in steps of 360°/MOD. Rev. 0 | Page 24 of 28 08226-025 ADF4150 APPLICATIONS INFORMATION DIRECT CONVERSION MODULATOR Direct conversion architectures are increasingly being used to implement base station transmitters. Figure 30 shows how Analog Devices, Inc., parts can be used to implement such a system. The circuit block diagram shows the AD9788 TxDAC® being used with the ADL5375. The use of dual integrated DACs, such as the AD9788 with its 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 local oscillator (LO) is implemented using the ADF4150. The low-pass filter was designed using ADIsimPLL™ for a channel spacing of 200 kHz and a closed-loop bandwidth of 35 kHz. The LO ports of the ADL5375 can be driven differentially from the RFOUT+ and RFOUT− outputs of the ADF4150. This gives better performance than a single-ended LO driver and eliminates the use of a balun to convert from a single-ended LO input to the more desirable differential LO inputs for the ADL5375. The typical rms phase noise (100 Hz to 5 MHz) of the LO in this configuration is 0.61°rms. The ADL5375 accepts LO drive levels from −10 dBm to 0 dBm. The optimum LO power can be software programmed on the ADF4150, which allows levels from −4 dBm to +5 dBm from each output. The RF output is designed to drive a 50 Ω load but must be ac-coupled, as shown in Figure 30. If the I and Q inputs are driven in quadrature by 2 V p-p signals, the resulting output power from the modulator is approximately 2 dBm. REFIO IOUTA MODULATED DIGITAL DATA IOUTB 51Ω 51Ω LOW-PASS FILTER AD9788 TxDAC QOUTA FSADJ 2kΩ QOUTB LOW-PASS FILTER 51Ω 51Ω VDD LOCK DETECT IBBP VVCO IBBN ADL5375 9 1nF 1nF FREF IN 19 REF IN 51Ω 1 2 3 SPI-COMPATIBLE SERIAL BUS 18 16 4 17 6 22 21 MUXOUT 20 LD RFOUT+ 15 RFOUT– 14 AVDD DVDD AVDD CE PDB RF VP SDV DD 3.9nH 3.9nH 1nF LOIP LOIN VVCO 1nF QUADRATURE PHASE SPLITTER RFOUT CLK DATA LE DSOP 100pF VCC VCO OUT VTUNE RFIN– 11 100pF 680Ω CP 7 39nF 2700pF SW 5 CPGND AGND AGND SDGND 8 12 13 23 08226-026 VCO QBBP QBBN ADF4150 24 RSET 4.7kΩ RFIN+ 10 1200pF 360Ω Figure 30. Direct Conversion Modulator Rev. 0 | Page 25 of 28 ADF4150 INTERFACING The ADF4150 has a simple SPI-compatible serial interface for writing to the device. CLK, DATA, and LE control the data transfer. When LE goes high, the 32 bits that have been clocked into the appropriate register on each rising edge of CLK are transferred to the appropriate latch. See Figure 2 for the timing diagram and Table 5 for the register address table. ADSP-21xx Interface Figure 32 shows the interface between the ADF4150 and a ADSP-21xx digital signal processor. The ADF4150 needs a 32-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 MOSI TFS CLK SDATA LE CE MUXOUT (LOCK DETECT) 08226-028 ADuC812 Interface Figure 31 shows the interface between the ADF4150 and the ADuC812 MicroConverter®. Because the ADuC812 is based on an 8051 core, this interface can be used with any 8051-based microcontroller. The MicroConverter is set up for SPI master mode with CPHA = 0. To initiate the operation, the I/O port driving LE is brought low. Each latch of the ADF4150 needs a 32-bit word, which is accomplished by writing four 8-bit bytes from the MicroConverter to the device. When the fourth byte has been written, the LE input should be brought high to complete the transfer. SCLOCK MOSI CLK SDATA LE CE MUXOUT (LOCK DETECT) 08226-027 ADSP-21xx I/O PORTS ADF4150 Figure 32. ADSP-21xx to ADF4150 Interface ADuC812 I/O PORTS ADF4150 Set up the word length for 8 bits and use four memory locations for each 32-bit word. To program each 32-bit latch, store the 8-bit bytes, enable the autobuffered mode, and write to the transmit register of the DSP. This last operation initiates the autobuffer transfer. PCB DESIGN GUIDELINES FOR CHIP SCALE PACKAGE The lands on the chip scale package (CP-24-7) are rectangular. The PCB pad for these is to be 0.1 mm longer than the package land length and 0.05 mm wider than the package land width. The land is to be centered on the pad. This ensures the solder joint size is maximized. The bottom of the chip scale package has a central thermal pad. The thermal pad on the PCB is to be at least as large as the exposed pad. On the PCB, there is to be a minimum clearance of 0.25 mm between the thermal pad and the inner edges of the pad pattern. This ensures that shorting is avoided. Thermal vias can be used on the PCB thermal pad to improve the thermal performance of the package. If vias are used, they are to be incorporated in the thermal pad at 1.2 mm pitch grid. The via diameter is to be between 0.3 mm and 0.33 mm, and the via barrel is to be plated with one ounce copper to plug the via. Figure 31. ADuC812 to ADF4150 Interface I/O port lines on the ADuC812 are also used to control powerdown (CE input) and detect lock (MUXOUT configured as lock detect and polled by the port input). When operating in the described mode, the maximum SCLOCK rate of the ADuC812 is 4 MHz. This means that the maximum rate at which the output frequency can be changed is 125 kHz. Rev. 0 | Page 26 of 28 ADF4150 OUTPUT MATCHING There are a number of ways to match the output of the ADF4150 for optimum operation; the most basic is to use a 50 Ω resistor to AVDD. A dc bypass capacitor of 100 pF is connected in series as shown in Figure 33. Because the resistor is not frequency dependent, this provides a good broadband match. The output power in this circuit into a 50 Ω load typically gives values chosen by Bits[DB4:DB3] in Register 4 (R4). AVDD 50Ω 100pF 50Ω 08226-029 Experiments indicate that the circuit shown in Figure 34 provides an excellent match to 50 Ω for the W-CDMA UMTS Band 1 (2110 MHz to 2170 MHz). The maximum output power in that case is about 7 dBm. Both single-ended architectures can be examined using the EVAL-ADF4150EB1Z evaluation board. AVDD 3.9nH 1nF RFOUT 08226-030 50Ω Figure 34. Optimum ADF4150 Output Stage RFOUT If differential outputs are not needed, the unused output can be terminated or combined with both outputs using a balun. Figure 33. Simple ADF4150 Output Stage A better solution is to use a shunt inductor (acting as an RF choke) to AVDD. This gives a better match and, therefore, more output power. Rev. 0 | Page 27 of 28 ADF4150 OUTLINE DIMENSIONS PIN 1 INDICATOR 4.10 4.00 SQ 3.90 0.50 BSC 0.30 0.25 0.18 19 18 EXPOSED PAD 24 1 PIN 1 INDICATOR 2.65 2.50 SQ 2.45 6 7 TOP VIEW 0.80 0.75 0.70 SEATING PLANE 0.50 0.40 0.30 13 12 0.25 MIN BOTTOM VIEW FOR PROPER CONNECTION OF THE EXPOSED PAD, REFER TO THE PIN CONFIGURATION AND FUNCTION DESCRIPTIONS SECTION OF THIS DATA SHEET. 0.05 MAX 0.02 NOM COPLANARITY 0.08 0.20 REF COMPLIANT TO JEDEC STANDARDS MO-220-WGGD. Figure 35. 24-Lead Lead Frame Chip Scale Package [LFCSP_WQ] 4 mm ×4 mm Body, Very Very Thin Quad (CP-24-7) Dimensions shown in millimeters ORDERING GUIDE Model 1 ADF4150BCPZ ADF4150BCPZ-RL7 EVAL-ADF4150EB1Z 1 Temperature Range −40°C to +85°C −40°C to +85°C Package Description 24-Lead Lead Frame Chip Scale Package [LFCSP_WQ] 24-Lead Lead Frame Chip Scale Package [LFCSP_WQ] Evaluation Board 112108-A Package Option CP-24-7 CP-24-7 Z = RoHS Compliant Part. ©2011 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D08226-0-7/11(0) Rev. 0 | Page 28 of 28