TLC2932 HIGH-PERFORMANCE PHASE-LOCKED LOOP SLAS097E – SEPTEMBER 1994 – REVISED MAY 1997 D D D D D D D D Voltage-Controlled Oscillator (VCO) Section: – Complete Oscillator Using Only One External Bias Resistor (RBIAS) – Lock Frequency: 22 MHz to 50 MHz (VDD = 5 V ±5%, TA = – 20°C to 75°C, ×1 Output) 11 MHz to 25 MHz (VDD = 5 V ±5%, TA = – 20°C to 75°C, ×1/2 Output) – Output Frequency . . . ×1 and ×1/2 Selectable Phase-Frequency Detector (PFD) Section Includes a High-Speed Edge-Triggered Detector With Internal Charge Pump Independent VCO, PFD Power-Down Mode Thin Small-Outline Package (14 terminal) CMOS Technology Typical Applications: – Frequency Synthesis – Modulation/Demodulation – Fractional Frequency Division Application Report Available† CMOS Input Logic Level PW PACKAGE† (TOP VIEW) LOGIC VDD SELECT VCO OUT FIN – A FIN – B PFD OUT LOGIC GND 1 2 3 4 5 6 7 VCO VDD BIAS VCO IN VCO GND VCO INHIBIT PFD INHIBIT NC 14 13 12 11 10 9 8 † Available in tape and reel only and ordered as the TLC2932IPWLE. NC – No internal connection description The TLC2932 is designed for phase-locked-loop (PLL) systems and is composed of a voltage-controlled oscillator (VCO) and an edge-triggered-type phase frequency detector (PFD). The oscillation frequency range of the VCO is set by an external bias resistor (RBIAS). The VCO has a 1/2 frequency divider at the output stage. The high-speed PFD with internal charge pump detects the phase difference between the reference frequency input and signal frequency input from the external counter. Both the VCO and the PFD have inhibit functions, which can be used as a power-down mode. The TLC2932 is suitable for use as a high-performance PLL due to the high speed and stable oscillation capability of the device. functional block diagram FIN –A FIN –B PFD INHIBIT 4 5 9 VCO IN Phase Frequency Detector 6 BIAS PFD OUT VCO INHIBIT SELECT 12 13 10 2 VoltageControlled Oscillator 3 VCO OUT AVAILABLE OPTIONS PACKAGE TA SMALL OUTLINE (PW) – 20°C to 75°C TLC2932IPWLE Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. † TLC2932 Phase-Locked-Loop Building Block With Analog Voltage-Controlled Oscillator and Phase Frequency Detector (SLAA011). Copyright 1997, Texas Instruments Incorporated PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 1 TLC2932 HIGH-PERFORMANCE PHASE-LOCKED LOOP SLAS097E – SEPTEMBER 1994 – REVISED MAY 1997 Terminal Functions TERMINAL NAME NO. I/O DESCRIPTION FIN – A 4 I Input reference frequency f(REF IN) is applied to FIN – A. FIN – B 5 I Input for VCO external counter output frequency f(FIN – B). FIN – B is nominally provided from the external counter. LOGIC GND 7 GND for the internal logic. LOGIC VDD 1 Power supply for the internal logic. This power supply should be separate from VCO VDD to reduce cross-coupling between supplies. NC 8 No internal connection. PFD INHIBIT 9 I PFD inhibit control. When PFD INHIBIT is high, PFD output is in the high-impedance state, see Table 3. PFD OUT 6 O PFD output. When the PFD INHIBIT is high, PFD output is in the high-impedance state. 13 I Bias supply. An external resistor (RBIAS) between VCO VDD and BIAS supplies bias for adjusting the oscillation frequency range. SELECT 2 I VCO output frequency select. When SELECT is high, the VCO output frequency is × 1/2 and when low, the output frequency is × 1, see Table 1. VCO IN 12 I VCO control voltage input. Nominally the external loop filter output connects to VCO IN to control VCO oscillation frequency. VCO INHIBIT 10 I VCO inhibit control. When VCO INHIBIT is high, VCO OUT is low (see Table 2). VCO GND 11 VCO OUT 3 VCO VDD 14 BIAS GND for VCO. O VCO output. When the VCO INHIBIT is high, VCO output is low. Power supply for VCO. This power supply should be separated from LOGIC VDD to reduce cross-coupling between supplies. detailed description VCO oscillation frequency The VCO oscillation frequency is determined by an external resistor (RBIAS) connected between the VCO VDD and the BIAS terminals. The oscillation frequency and range depends on this resistor value. The bias resistor value for the minimum temperature coefficient is nominally 3.3 kΩ with 3-V at the VCO VDD terminal and nominally 2.2 kΩ with 5-V at the VCO VDD terminal. For the lock frequency range refer to the recommended operating conditions. Figure 1 shows the typical frequency variation and VCO control voltage. VCO Oscillation Frequency (f osc ) VCO Oscillation Frequency Range Bias Resistor (RBIAS) 1/2 VDD VCO Control Voltage (VCO IN) Figure 1. VCO Oscillation Frequency 2 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TLC2932 HIGH-PERFORMANCE PHASE-LOCKED LOOP SLAS097E – SEPTEMBER 1994 – REVISED MAY 1997 VCO output frequency 1/2 divider The TLC2932 SELECT terminal sets the fosc or 1/2 fosc VCO output frequency as shown in Table 1. The 1/2 fosc output should be used for minimum VCO output jitter. Table 1. VCO Output 1/2 Divider Function SELECT VCO OUTPUT Low fosc 1/2 fosc High VCO inhibit function The VCO has an externally controlled inhibit function which inhibits the VCO output. A high level on the VCO INHIBIT terminal stops the VCO oscillation and powers down the VCO. The output maintains a low level during the power-down mode, refer to Table 2. Table 2. VCO Inhibit Function VCO INHIBIT VCO OSCILLATOR VCO OUTPUT Low Active Active IDD(VCO) Normal High Stopped Low level Power Down PFD operation The PFD is a high-speed, edge-triggered detector with an internal charge pump. The PFD detects the phase difference between two frequency inputs supplied to FIN–A and FIN–B as shown in Figure 2. Nominally the reference is supplied to FIN–A, and the frequency from the external counter output is fed to FIN–B. FIN– A FIN– B VOH PFD OUT Hi-Z VOL Figure 2. PFD Function Timing Chart PFD output control A high level on the PFD INHIBIT terminal places the PFD output in the high-impedance state and the PFD stops phase detection as shown in Table 3. A high level on the PFD INHIBIT terminal also can be used as the power-down mode for the PFD. Table 3. VCO Output Control Function PFD INHIBIT DETECTION PFD OUTPUT Low Active Active IDD(PFD) Normal High Stopped Hi-Z Power Down POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 3 TLC2932 HIGH-PERFORMANCE PHASE-LOCKED LOOP SLAS097E – SEPTEMBER 1994 – REVISED MAY 1997 schematics VCO block schematic RBIAS BIAS 1/2 VCO IN VCO Output Bias Control M U X VCO OUT SELECT VCO INHIBIT PFD block schematic Charge Pump VDD FIN – A PFD OUT Detector FIN – B PFD INHIBIT absolute maximum ratings† Supply voltage (each supply), VDD (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V Input voltage range (each input), VI (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.5 V to VDD + 0.5 V Input current (each input), II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 20 mA Output current (each output), IO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 20 mA Continuous total power dissipation, at (or below) TA = 25°C (see Note 2) . . . . . . . . . . . . . . . . . . . . . . . 700 mW Operating free-air temperature range, TA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 20°C to 75°C Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 65°C to 150°C Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260°C † Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. NOTES: 1. All voltage values are with respect to network GND. 2. For operation above 25°C free-air temperature, derate linearly at the rate of 5.6 mW/°C. 4 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TLC2932 HIGH-PERFORMANCE PHASE-LOCKED LOOP SLAS097E – SEPTEMBER 1994 – REVISED MAY 1997 recommended operating conditions PARAMETER VDD = 3 V VDD = 5 V supply see Note 3) Supply voltage voltage, VDD (each supply, Input voltage, VI (inputs except VCO IN) MIN NOM MAX 2.85 3 3.15 4.75 5 5.25 0 Output current, IO (each output) VDD ±2 0 VCO control voltage at VCO IN 0.9 Lock frequency (×1 output) VDD = 3 V VDD = 5 V Lock frequency (×1/2 output) VDD = 3 V VDD = 5 V Bias resistor, resistor RBIAS VDD = 3 V VDD = 5 V 14 VDD 21 22 50 7 10.5 11 25 2.2 3.3 4.3 1.5 2.2 3.3 UNIT V V mA V MHz MHz kΩ NOTE 3: It is recommended that the logic supply terminal (LOGIC VDD) and the VCO supply terminal (VCO VDD) should be at the same voltage and separated from each other. electrical characteristics over recommended operating free-air temperature range, VDD = 3 V (unless otherwise noted) VCO section PARAMETER TEST CONDITIONS VOH VOL High-level output voltage IOH = – 2 mA IOL = 2 mA VIT II Input threshold voltage at SELECT, VCO INHIBIT Zi(VCO IN) IDD(INH) Input impedance VI = VDD or GND VCO IN = 1/2 VDD VCO supply current (inhibit) See Note 4 Low-level output voltage Input current at SELECT, VCO INHIBIT MIN TYP MAX 2.4 V 0.3 0.9 UNIT 1.5 V ±1 µA 10 0.01 IDD(VCO) VCO supply current See Note 5 5 NOTES: 4. Current into VCO VDD, when VCO INHIBIT = VDD, PFD is inhibited. 5. Current into VCO VDD, when VCO IN = 1/2 VDD, RBIAS = 3.3 kΩ, VCO INHIBIT = GND, and PFD is inhibited. V 2.1 MΩ 1 µA 15 mA PFD section PARAMETER TEST CONDITIONS IOH = – 2 mA IOL = 2 mA MIN TYP MAX High-level output voltage IOZ High-impedance-state output current VIH VIL High-level input voltage at FIN–A, FIN–B VIT Ci Input threshold voltage at PFD INHIBIT Input capacitance at FIN–A, FIN–B 5 pF Zi IDD(Z) Input impedance at FIN–A, FIN–B 10 MΩ Low-level output voltage 2.7 UNIT VOH VOL V PFD INHIBIT = high, VI = VDD or GND V ±1 µA 2.7 V Low-level input voltage at FIN–A, FIN–B High-impedance-state PFD supply current 0.2 0.5 0.9 See Note 6 1.5 0.01 2.1 1 V V µA IDD(PFD) PFD supply current See Note 7 0.1 1.5 mA NOTES: 6. Current into LOGIC VDD, when FIN–A, FIN–B = GND, PFD INHIBIT = VDD, no load, and VCO OUT is inhibited. 7. Current into LOGIC VDD, when FIN–A, FIN–B = 1 MHz (VI(PP) = 3 V, rectangular wave), NC = GND, no load, and VCO OUT is inhibited. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 5 TLC2932 HIGH-PERFORMANCE PHASE-LOCKED LOOP SLAS097E – SEPTEMBER 1994 – REVISED MAY 1997 operating characteristics over recommended operating free-air temperature range, VDD = 3 V (unless otherwise noted) VCO section PARAMETER fosc ts(fosc) TEST CONDITIONS Operating oscillation frequency RBIAS = 3.3 kΩ, VCO IN = 1/2 VDD Time to stable oscillation (see Note 8) Measured from VCO INHIBIT↓ tr Rise time tf Fall time MIN TYP MAX UNIT 15 19 23 MHz 10 µs CL = 15 pF, See Figure 3 7 CL = 50 pF, See Figure 3 14 CL = 15 pF, See Figure 3 6 CL = 50 pF, See Figure 3 10 45% 50% 14 12 ns ns Duty cycle at VCO OUT RBIAS = 3.3 kΩ, VCO IN = 1/2 VDD, 55% α(fosc) Temperature coefficient of oscillation frequency RBIAS = 3.3 kΩ, VCO IN = 1/2 VDD, TA = –20°C to 75°C 0.04 %/°C kSVS(fosc) Supply voltage coefficient of oscillation frequency RBIAS = 3.3 kΩ, VCO IN = 1.5 V, VDD = 2.85 V to 3.15 V 0.02 %/mV Jitter absolute (see Note 9) RBIAS = 3.3 kΩ 100 ps NOTES: 8. The time period to the stable VCO oscillation frequency after the VCO INHIBIT terminal is changed to a low level. 9. The low-pass-filter (LPF) circuit is shown in Figure 28 with calculated values listed in Table 7. Jitter performance is highly dependent on circuit layout and external device characteristics. The jitter specification was made with a carefully designed PCB with no device socket. PFD section PARAMETER TEST CONDITIONS MIN TYP MAX fmax tPLZ Maximum operating frequency PFD output disable time from low level 21 50 tPHZ tPZL PFD output disable time from high level 23 50 tPZH tr PFD output enable time to high level tf Fall time 6 PFD output enable time to low level 20 See Figures 4 and 5 and Table 4 Rise time pF CL = 15 pF, POST OFFICE BOX 655303 See Figure 4 • DALLAS, TEXAS 75265 UNIT MHz ns 11 30 10 30 2.3 10 ns 2.1 10 ns ns TLC2932 HIGH-PERFORMANCE PHASE-LOCKED LOOP SLAS097E – SEPTEMBER 1994 – REVISED MAY 1997 electrical characteristics over recommended operating free-air temperature range, VDD = 5 V (unless otherwise noted) VCO section PARAMETER TEST CONDITIONS VOH VOL High-level output voltage IOH = – 2 mA IOL = 2 mA VIT II Input threshold voltage at SELECT, VCO INHIBIT Zi(VCO IN) IDD(INH) Input impedance VI = VDD or GND VCO IN = 1/2 VDD VCO supply current (inhibit) See Note 4 Low-level output voltage Input current at SELECT, VCO INHIBIT MIN TYP MAX 4 V 0.5 1.5 UNIT 2.5 V ±1 µA 10 0.01 IDD(VCO) VCO supply current See Note 5 15 NOTES: 4. Current into VCO VDD, when VCO INHIBIT = VDD, and PFD is inhibited. 5. Current into VCO VDD, when VCO IN = 1/2 VDD, RBIAS = 3.3 kΩ, VCO INHIBIT = GND, and PFD is inhibited. V 3.5 MΩ 1 µA 35 mA PFD section PARAMETER TEST CONDITIONS IOH = 2 mA IOL = 2 mA MIN TYP MAX VOH VOL High-level output voltage IOZ High-impedance-state output current VIH VIL High-level input voltage at FIN–A, FIN–B VIT Ci Input threshold voltage at PFD INHIBIT Input capacitance at FIN–A, FIN–B 5 pF Zi IDD(Z) Input impedance at FIN–A, FIN–B 10 MΩ Low-level output voltage 4.5 UNIT V PFD INHIBIT = high, VI = VDD or GND V ±1 µA 4.5 V Low-level input voltage at FIN–A, FIN–B High-impedance-state PFD supply current 0.2 1.5 See Note 6 2.5 0.01 1 V 3.5 V 1 µA IDD(PFD) PFD supply current See Note 7 0.15 3 mA NOTES: 6. Current into LOGIC VDD, when FIN–A, FIN–B = GND, PFD INHIBIT = VDD, no load, and VCO OUT is inhibited. 7. Current into LOGIC VDD, when FIN–A, FIN–B = 1 MHz (VI(PP) = 5 V, rectangular wave), PFD INHIBIT = GND, no load, and VCO OUT is inhibited. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 7 TLC2932 HIGH-PERFORMANCE PHASE-LOCKED LOOP SLAS097E – SEPTEMBER 1994 – REVISED MAY 1997 operating characteristics over recommended operating free-air temperature range, VDD = 5 V (unless otherwise noted) VCO section PARAMETER fosc ts(fosc) TEST CONDITIONS Operating oscillation frequency RBIAS = 2.2 kΩ, VCO IN = 1/2 VDD Time to stable oscillation (see Note 8) Measured from VCO INHIBIT↓ tr Rise time tf Fall time MIN TYP MAX UNIT 30 41 52 MHz 10 µs CL = 15 pF, See Figure 3 5.5 CL = 50 pF, See Figure 3 8 CL = 15 pF, See Figure 3 5 CL = 50 pF, See Figure 3 6 Duty cycle at VCO OUT RBIAS = 2.2 kΩ, VCO IN = 1/2 VDD, α(fosc) Temperature coefficient of oscillation frequency RBIAS = 2.2 kΩ, VCO IN = 1/2 VDD, TA = –20°C to 75°C kSVS(fosc) Supply voltage coefficient of oscillation frequency RBIAS = 2.2 kΩ, VCO IN = 2.5 V, VDD = 4.75 V to 5.25 V Jitter absolute (see Note 9) RBIAS = 2.2 kΩ 45% 50% 10 10 ns ns 55% 0.06 %/°C 0.006 %/mV 100 ps NOTES: 8: The time period to the stable VCO oscillation frequency after the VCO INHIBIT terminal is changed to a low level. 9. The LPF circuit is shown in Figure 28 with calculated values listed in Table 7. Jitter performance is highly dependent on circuit layout and external device characteristics. The jitter specification was made with a carefully designed PCB with no device socket. PFD section PARAMETER TEST CONDITIONS fmax tPLZ Maximum operating frequency tPHZ tPZL PFD output disable time from high level tPZH tr PFD output enable time to high level tf Fall time 8 TYP MAX 21 40 20 40 7.3 20 6.5 20 2.3 10 ns 1.7 10 ns 40 PFD output disable time from low level PFD output enable time to low level MIN See Figures 4 and 5 and Table 4 Rise time CL = 15 pF, pF POST OFFICE BOX 655303 See Figure 4 • DALLAS, TEXAS 75265 UNIT MHz ns ns TLC2932 HIGH-PERFORMANCE PHASE-LOCKED LOOP SLAS097E – SEPTEMBER 1994 – REVISED MAY 1997 PARAMETER MEASUREMENT INFORMATION 90% 90% VCO OUT 10% 10% tr tf Figure 3. VCO Output Voltage Waveform FIN– A† FIN– B† VDD VDD GND GND VDD VDD GND GND VDD PFD INHIBIT VDD 50% 50% GND tPHZ tr PFD OUT 10% GND VOH 90% 50% tPLZ tf 90% 50% GND 50% 10% VDD 50% VOL tPZL tPZH (a) OUTPUT PULLDOWN (see Figure 5 and Table 4) (b) OUTPUT PULLUP (see Figure 5 and Table 4) † FIN–A and FIN–B are for reference phase only, not for timing. Figure 4. PFD Output Voltage Waveform Table 4. PFD Output Test Conditions PARAMETER RL CL tPZH tPHZ tr tPZL tPLZ tf S1 S2 Open Close VDD Test Point S1 1 kΩ RL DUT 15 pF Close PFD OUT Open CL S2 Figure 5. PFD Output Test Conditions POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 9 TLC2932 HIGH-PERFORMANCE PHASE-LOCKED LOOP SLAS097E – SEPTEMBER 1994 – REVISED MAY 1997 TYPICAL CHARACTERISTICS VCO OSCILLATION FREQUENCY vs VCO CONTROL VOLTAGE VCO OSCILLATION FREQUENCY vs VCO CONTROL VOLTAGE VDD = 3 V RBIAS = 2.2 kΩ 100 VDD = 5 V RBIAS = 1.5 kΩ – 20°C 25°C f osc – VCO Oscillation Frequency – MHz f osc – VCO Oscillation Frequency – MHz 40 30 75°C 20 10 – 20°C 80 25°C 60 75°C 40 20 0 0 1 2 VCO IN – VCO Control Voltage – V 3 4 1 2 3 VCO IN – VCO Control Voltage – V 0 Figure 6 Figure 7 VCO OSCILLATION FREQUENCY vs VCO CONTROL VOLTAGE VCO OSCILLATION FREQUENCY vs VCO CONTROL VOLTAGE 80 VDD = 3 V RBIAS = 3.3 kΩ f osc – VCO Oscillation Frequency – MHz f osc – VCO Oscillation Frequency – MHz 40 – 20°C 30 75°C 25°C 20 10 0 0 1 2 VCO IN – VCO Control Voltage – V 3 VDD = 5 V RBIAS = 2.2 kΩ – 20°C 60 75°C 25°C 40 20 0 0 Figure 8 10 5 1 2 3 4 VCO IN – VCO Control Voltage – V Figure 9 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 5 TLC2932 HIGH-PERFORMANCE PHASE-LOCKED LOOP SLAS097E – SEPTEMBER 1994 – REVISED MAY 1997 TYPICAL CHARACTERISTICS VCO OSCILLATION FREQUENCY vs VCO CONTROL VOLTAGE VCO OSCILLATION FREQUENCY vs VCO CONTROL VOLTAGE 80 VDD = 3 V RBIAS = 4.3 kΩ f osc – VCO Oscillation Frequency – MHz f osc – VCO Oscillation Frequency – MHz 40 30 75°C 25°C 20 – 20°C 10 0 0 1 2 VCO IN – VCO Control Voltage – V VDD = 5 V RBIAS = 3.3 kΩ 60 40 25°C 20 – 20°C 0 3 75°C 0 1 2 3 4 VCO IN – VCO Control Voltage – V Figure 10 Figure 11 VCO OSCILLATION FREQUENCY vs BIAS RESISTOR VCO OSCILLATION FREQUENCY vs BIAS RESISTOR 30 60 VDD = 3 V VCO IN = 1/2 VDD TA = 25°C f osc – VCO Oscillation Frequency – MHz f osc – VCO Oscillation Frequency – MHz 5 25 20 15 10 2 2.5 3.5 4 3 RBIAS – Bias Resistor – kΩ 4.5 VDD = 5 V VCO IN = 1/2 VDD TA = 25°C 50 40 30 20 1.5 Figure 12 2 2.5 3 RBIAS – Bias Resistor – kΩ 3.5 Figure 13 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 11 TLC2932 HIGH-PERFORMANCE PHASE-LOCKED LOOP SLAS097E – SEPTEMBER 1994 – REVISED MAY 1997 TYPICAL CHARACTERISTICS TEMPERATURE COEFFICIENT OF OSCILLATION FREQUENCY vs BIAS RESISTOR 0.4 VDD = 3 V VCO IN = 1/2 VDD TA = – 20°C to 75°C α (f osc) – Temperature Coefficient of Oscillation Frequency – % / °C α (f osc) – Temperature Coefficient of Oscillation Frequency – % / °C 0.4 TEMPERATURE COEFFICIENT OF OSCILLATION FREQUENCY vs BIAS RESISTOR 0.3 0.2 0.1 0 2 3 2.5 4 3.3 3.5 RBIAS – Bias Resistor – kΩ VDD = 5 V VCO IN = 1/2 VDD TA = – 20°C to 75°C 0.3 0.2 0.1 0 1.5 4.5 VCO OSCILLATION FREQUENCY vs VCO SUPPLY VOLTAGE VCO OSCILLATION FREQUENCY vs VCO SUPPLY VOLTAGE 48 24 RBIAS = 3.3 kΩ VCO IN = 1.5 V TA = 25°C f osc – VCO Oscillation Frequency – MHz f osc – VCO Oscillation Frequency – MHz 3.5 Figure 15 Figure 14 22 20 18 16 3.05 3 VDD – VCO Supply Voltage – V 3.15 RBIAS = 2.2 kΩ VCO IN = 1/2 VDD TA = 25°C 44 40 36 32 4.75 Figure 16 12 2 2.5 3 2.2 RBIAS – Bias Resistor – kΩ 5 VDD – VCO Supply Voltage – V Figure 17 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 5.25 TLC2932 HIGH-PERFORMANCE PHASE-LOCKED LOOP SLAS097E – SEPTEMBER 1994 – REVISED MAY 1997 TYPICAL CHARACTERISTICS 0.05 VDD = 2.85 V to 3.15 V VCO IN = 1/2 VDD TA = 25°C 0.04 0.03 0.02 0.01 0 2 2.5 3 3.5 4 RBIAS – Bias Resistor – kΩ 4.5 SUPPLY VOLTAGE COEFFICIENT OF VCO OSCILLATION FREQUENCY vs BIAS RESISTOR α (f osc) – Supply Voltage Coefficient of VCO Oscillation Frequency – % / V α (f osc) – Supply Voltage Coefficient of VCO Oscillation Frequency – % / V SUPPLY VOLTAGE COEFFICIENT OF VCO OSCILLATION FREQUENCY vs BIAS RESISTOR VDD = 4.75 V to 5.25 V VCO IN = 1/2 VDD TA = 25°C 0.01 0.005 0 1.5 2 2.5 3 RBIAS – Bias Resistor – kΩ Figure 18 Figure 19 RECOMMENDED LOCK FREQUENCY (×1 OUTPUT) vs BIAS RESISTOR RECOMMENDED LOCK FREQUENCY (×1 OUTPUT) vs BIAS RESISTOR 60 30 VDD = 2.85 V to 3.15 V TA = – 20°C to 75°C Recommended Lock Frequency – MHz Recommended Lock Frequency – MHz 3.5 25 20 15 10 2 2.5 3 3.5 4 RBIAS – Bias Resistor – kΩ 4.5 VDD = 4.75 V to 5.25 V TA = – 20°C to 75°C 50 40 30 20 10 1.5 Figure 20 2 2.5 3 RBIAS – Bias Resistor – kΩ 3.5 Figure 21 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 13 TLC2932 HIGH-PERFORMANCE PHASE-LOCKED LOOP SLAS097E – SEPTEMBER 1994 – REVISED MAY 1997 APPLICATION INFORMATION RECOMMENDED LOCK FREQUENCY (×1/2 OUTPUT) vs BIAS RESISTOR RECOMMENDED LOCK FREQUENCY (×1/2 OUTPUT) vs BIAS RESISTOR 30 VDD = 2.85 V to 3.15 V TA = – 20°C to 75°C SELECT = VDD Recommended Lock Frequency – MHz Recommended Lock Frequency – MHz 15 12.5 10 7.5 5 2 2.5 3.5 4 3 RBIAS – Bias Resistor – kΩ 4.5 25 VDD = 4.75 V to 5.25 V TA = – 20°C to 75°C SELECT = VDD 20 15 10 5 1.5 Figure 23 Figure 22 14 2 2.5 3 RBIAS – Bias Resistor – kΩ POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 3.5 TLC2932 HIGH-PERFORMANCE PHASE-LOCKED LOOP SLAS097E – SEPTEMBER 1994 – REVISED MAY 1997 APPLICATION INFORMATION gain of VCO and PFD Figure 24 is a block diagram of the PLL. The countdown N value depends on the input frequency and the desired VCO output frequency according to the system application requirements. The Kp and KV values are obtained from the operating characteristics of the device as shown in Figure 24. Kp is defined from the phase detector VOL and VOH specifications and the equation shown in Figure 24(b). KV is defined from Figures 8, 9, 10, and 11 as shown in Figure 24(c). The parameters for the block diagram with the units are as follows: KV : VCO gain (rad/s/V) Kp : PFD gain (V/rad) Kf : LPF gain (V/V) KN : count down divider gain (1/N) Divider (KN = 1/N) PFD (Kp) f REF VCO (KV) TLC2932 LPF (Kf) VOH (a) – 2π – π 0 π 2π fMAX VOH VOL fMIN Range of Comparison external counter When a large N counter is required by the application, there is a possibility that the PLL response becomes slow due to the counter response delay time. In the case of a high frequency application, the counter delay time should be accounted for in the overall PLL design. VIN MIN Kp = VOH – VOL 4π (b) KV = VIN MAX 2π(fMAX – fMIN) VIN MAX – VIN MIN (c) Figure 24. Example of a PLL Block Diagram RBIAS The external bias resistor sets the VCO center frequency with 1/2 VDD applied to the VCO IN terminal. However, for optimum temperature performance, a resistor value of 3.3 kΩ with a 3-V supply and a resistor value of 2.5 kΩ for a 5-V supply is recommended. For the most accurate results, a metal-film resistor is the better choice but a carbon-compositiion resistor can be used with excellent results also. A 0.22 µF capacitor should be connected from the BIAS terminal to ground as close to the device terminals as possible. hold-in range From the technical literature, the maximum hold-in range for an input frequency step for the three types of filter configurations shown in Figure 25 is as follows: DwH ] 0.8 Where ǒ Ǔ ǒ Ǔ ǒ RǓ Kp K V K ( ) f Kf (∞) = the filter transfer function value at ω = ∞ POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 15 TLC2932 HIGH-PERFORMANCE PHASE-LOCKED LOOP SLAS097E – SEPTEMBER 1994 – REVISED MAY 1997 APPLICATION INFORMATION low-pass-filter (LPF) configurations Many excellent references are available that include detailed design information about LPFs and should be consulted for additional information. Lag-lead filters or active filters are often used. Examples of LPFs are shown in Figure 25. When the active filter of Figure 25(c) is used, the reference should be applied to FIN-B because of the amplifier inversion. Also, in practical filter implementations, C2 is used as additional filtering at the VCO input. The value of C2 should be equal to or less than one tenth the value of C1. C2 R1 R1 VI VO T1 = C1R1 C1 VI VO T1 = C1R1 T2 = C1R2 R2 C1 R2 C2 C1 – VI R1 (a) LAG FILTER A VO T1 = C1R1 T2 = C1R2 (b) LAG-LEAD FILTER (c) ACTIVE FILTER Figure 25. LPF Examples for PLL the passive filter The transfer function for the lag-lead filter shown in Figure 25(b) is; V V O IN + 1 )1s)@ s(T1@ T2 ) T2) Where T1 + R1 @ C1 and T2 + R2 @ C1 Using this filter makes the closed loop PLL system a second-order type 1 system. The response curves of this system to a unit step are shown in Figure 26. the active filter When using the active integrator shown in Figure 25(c), the phase detector inputs must be reversed since the integrator adds an additional inversion. Therefore, the input reference frequency should be applied to the FIN-B terminal and the output of the VCO divider should be applied to the input reference terminal, FIN-A. The transfer function for the active filter shown in Figure 25(c) is: F(s) + 1 )s @s @R1R2@ @C1C1 Using this filter makes the closed loop PLL system a second-order type 2 system. The response curves of this system to a unit step are shown in Figure 27. basic design example The following design example presupposes that the input reference frequency and the required frequency of the VCO are within the respective ranges of the device. 16 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TLC2932 HIGH-PERFORMANCE PHASE-LOCKED LOOP SLAS097E – SEPTEMBER 1994 – REVISED MAY 1997 APPLICATION INFORMATION basic design example (continued) Assume the loop has to have a 100 µs settling time (ts) with a countdown N = 8. Using the Type 1, second order response curves of Figure 26, a value of 4.5 radians is selected for ωnts with a damping factor of 0.7. This selection gives a good combination for settling time, accuracy, and loop gain margin. The initial parameters are summarized in Table 5. The loop constants, KV and Kp, are calculated from the data sheet specifications and Table 6 shows these values. The natural loop frequency is calculated as follows: Since w nt s Then wn + 4.5 + 1004.5ms + 45 k-radiansńsec Table 5. Design Parameters PARAMETER SYMBOL VALUE UNITS Division factor N 8 Lockup time t 100 µs ωnt 4.5 rad ζ 0.7 Radian value to selected lockup time Damping factor Table 6. Device Specifications PARAMETER SYMBOL VCO gain fMAX fMIN VALUE UNITS 76.6 Mrad/V/s 70 MHz 20 MHz 5 V KV VIN MAX VIN MIN PFD gain Kp 0.9 V 0.342357 V/rad Table 7. Calculated Values PARAMETER Natural angular frequency SYMBOL VALUE UNITS ωn 45000 rad/sec 3.277 Mrad/sec K = (KV • Kp)/N Lag-lead filter Calculated value Nearest standard value R1 15870 16000 Ω Calculated value Nearest standard value R2 308 300 Ω Selected value C1 0.1 µF POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 17 TLC2932 HIGH-PERFORMANCE PHASE-LOCKED LOOP SLAS097E – SEPTEMBER 1994 – REVISED MAY 1997 APPLICATION INFORMATION Using the low-pass filter in Figure 25(b) and divider ratio N, the transfer function for phase and frequency are shown in equations 1 and 2. Note that the transfer function for phase differs from the transfer function for frequency by only the divider value N. The difference arises from the fact that the feedback for phase is unity while the feedback for frequency is 1/N. Hence, transfer function of Figure 24 (a) for phase is F2(s) + F1(s) N @ @) K Kp (T1 V T2) ȱȧ ȧȧ Ȳ s2 ȱȧ ȧȧ Ȳ ƪ )s 1) @ @@ )@ ) ƫ 1 s T2 Kp K T2 V N (T1 T2) ) @ @) Kp K OUT(s) F REF(s) Kp @ K V + (T1 ) T2) s2 Ǹ@@ ƪ )s@ 1) @ @ )@ @ ) ƫ 1 s T2 K p K T2 V N (T1 T2) (1) V N (T1 T2) and the transfer function for frequency is F ȳȧ ȧȧ ȴ ȳȧ ȧȧ ȴ ) N@(T1@)VT2) Kp K (2) The standard two-pole denominator is D = s2 + 2 ζ ωn s + ωn2 and comparing the coefficients of the denominator of equation 1 and 2 with the standard two-pole denominator gives the following results. wn + Kp N (T1 K ) T2) V Solving for T1 + T2 T1 ) T2 + KNp@@wKV2 ǒ (3) n Ǔ and by using this value for T1 + T2 in equation 3 the damping factor is z + w2n @ T2 ) Kp @N K V solving for T2 T2 + 2wz – Kp @N K @ @ V then by substituting for T2 in equation 3 K Kp 2 z V N T1 – w 2 K n N wn p KV + 18 ) @ POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TLC2932 HIGH-PERFORMANCE PHASE-LOCKED LOOP SLAS097E – SEPTEMBER 1994 – REVISED MAY 1997 ƪ @ ƫ APPLICATION INFORMATION From the circuit constants and the initial design parameters then R2 R1 + ȱȧ Ȳ + z N wn * Kp K 2 Kp wn @ @ 2 z N * ) w K n p@K N Kv 2 V 1 C1 ȳȧ ȴ 1 C1 V The capacitor, C1, is usually chosen between 1 µF and 0.1 µF to allow for reasonable resistor values and physical capacitor size. In this example, C1 is chosen to be 0.1 µF and the corresponding R1 and R2 calculated values are listed in Table 7. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 19 TLC2932 HIGH-PERFORMANCE PHASE-LOCKED LOOP SLAS097E – SEPTEMBER 1994 – REVISED MAY 1997 APPLICATION INFORMATION 1.9 1.8 z = 0.1 1.7 z = 0.2 1.6 z = 0.3 1.5 z = 0.4 1.4 z = 0.6 z = 0.5 1.3 z = 0.7 1.2 φ 2 (t), Normalized Response z = 0.8 1.1 1 0.9 z = 1.0 0.8 z = 1.5 0.7 0.6 z = 2.0 0.5 0.4 0.3 0.2 0.1 0 0 1 2 3 4 5 6 ωnts = 4.5 7 8 9 10 ωnt Figure 26. Type 1 Second-Order Step Response 20 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 11 12 13 TLC2932 HIGH-PERFORMANCE PHASE-LOCKED LOOP SLAS097E – SEPTEMBER 1994 – REVISED MAY 1997 APPLICATION INFORMATION 1.9 ζ = 0.1 1.8 1.7 ζ = 0.2 1.6 ζ = 0.3 1.5 ζ = 0.4 ζ = 0.5 1.4 ζ = 0.6 1.3 φ 0 (t), Normalized Output Frequency ζ = 0.7 1.2 1.1 1 0.9 ζ = 0.8 0.8 ζ = 1.0 0.7 ζ = 2.0 0.6 0.5 0.4 0.3 0.2 0.1 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 ωnt Figure 27. Type 2 Second-Order Step Response POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 21 TLC2932 HIGH-PERFORMANCE PHASE-LOCKED LOOP SLAS097E – SEPTEMBER 1994 – REVISED MAY 1997 APPLICATION INFORMATION AVDD VDD 1 2 VCO LOGIC VDD (Digital) SELECT 14 VCO VDD 1/2 fosc R1† 13 BIAS 0.22 µF REF IN DGND 3 VCO OUT 4 FIN – A 5 FIN – B 6 PFD OUT VCO IN VCO GND R3 12 11 C2 R2 C1 VCO INHIBIT 10 AGND 7 Divide By N Phase Comparator PFD INHIBIT 9 LOGIC GND (Digital) NC 8 DGND S3 S4 S5 R4 R5 R6 DGND DVDD † RBIAS resistor Figure 28. Evaluation and Operation Schematic PCB layout considerations The TLC2932 contains a high frequency analog oscillator; therefore, very careful breadboarding and printed-circuit-board (PCB) layout is required for evaluation. The following design recommendations benefit the TLC2932 user: D D D D D D 22 External analog and digital circuitry should be physically separated and shielded as much as possible to reduce system noise. RF breadboarding or RF PCB techniques should be used throughout the evaluation and production process. Wide ground leads or a ground plane should be used on the PCB layouts to minimize parasitic inductance and resistance. The ground plane is the better choice for noise reduction. LOGIC VDD and VCO VDD should be separate PCB traces and connected to the best filtered supply point available in the system to minimize supply cross-coupling. VCO VDD to GND and LOGIC VDD to GND should be decoupled with a 0.1-µF capacitor placed as close as possible to the appropriate device terminals. The no-connection (NC) terminal on the package should be connected to GND. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TLC2932 HIGH-PERFORMANCE PHASE-LOCKED LOOP SLAS097E – SEPTEMBER 1994 – REVISED MAY 1997 MECHANICAL DATA PW (R-PDSO-G**) PLASTIC SMALL-OUTLINE PACKAGE 14 PIN SHOWN 0,32 0,17 0,65 14 0,13 M 8 0,15 NOM 4,70 4,30 6,70 6,10 Gage Plane 0,25 1 7 0°– 8° 0,70 0,40 A Seating Plane 1,20 MAX 0,10 0,10 MIN PINS ** 8 14 16 20 24 28 A MAX 3,30 5,30 5,30 6,80 8,10 10,00 A MIN 2,90 4,90 4,90 6,40 7,70 9,60 DIM 4040064 / B 10/94 NOTES: A. All linear dimensions are in millimeters. B. This drawing is subject to change without notice. C. Body dimensions do not include mold flash or protrusion not to exceed 0,15. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 23 IMPORTANT NOTICE Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent TI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed, except those mandated by government requirements. CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (“CRITICAL APPLICATIONS”). TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, AUTHORIZED, OR WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT DEVICES OR SYSTEMS OR OTHER CRITICAL APPLICATIONS. INCLUSION OF TI PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO BE FULLY AT THE CUSTOMER’S RISK. In order to minimize risks associated with the customer’s applications, adequate design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards. TI assumes no liability for applications assistance or customer product design. TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property right of TI covering or relating to any combination, machine, or process in which such semiconductor products or services might be or are used. TI’s publication of information regarding any third party’s products or services does not constitute TI’s approval, warranty or endorsement thereof. Copyright 1999, Texas Instruments Incorporated