LM565/LM565C Phase Locked Loop General Description The LM565 and LM565C are general purpose phase locked loops containing a stable, highly linear voltage controlled oscillator for low distortion FM demodulation, and a double balanced phase detector with good carrier suppression. The VCO frequency is set with an external resistor and capacitor, and a tuning range of 10:1 can be obtained with the same capacitor. The characteristics of the closed loop system — bandwidth, response speed, capture and pull in range — may be adjusted over a wide range with an external resistor and capacitor. The loop may be broken between the VCO and the phase detector for insertion of a digital frequency divider to obtain frequency multiplication. The LM565H is specified for operation over the −55˚C to +125˚C military temperature range. The LM565CN is specified for operation over the 0˚C to +70˚C temperature range. Features n 200 ppm/˚C frequency stability of the VCO n Power supply range of ± 5 to ± 12 volts with 100 ppm/% typical n 0.2% linearity of demodulated output n Linear triangle wave with in phase zero crossings available n TTL and DTL compatible phase detector input and square wave output n Adjustable hold in range from ± 1% to > ± 60% Applications n n n n n n n n n n n Data and tape synchronization Modems FSK demodulation FM demodulation Frequency synthesizer Tone decoding Frequency multiplication and division SCA demodulators Telemetry receivers Signal regeneration Coherent demodulators Connection Diagrams Metal Can Package Dual-in-Line Package DS007853-2 Order Number LM565H See NS Package Number H10C © 1999 National Semiconductor Corporation DS007853 DS007853-3 Order Number LM565CN See NS Package Number N14A www.national.com LM565/LM565C Phase Locked Loop May 1999 Absolute Maximum Ratings (Note 1) Operating Temperature Range LM565H LM565CN Storage Temperature Range Lead Temperature (Soldering, 10 sec.) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. ± 12V 1400 mW ± 1V Supply Voltage Power Dissipation (Note 2) Differential Input Voltage −55˚C to +125˚C 0˚C to +70˚C −65˚C to +150˚C 260˚C Electrical Characteristics AC Test Circuit, TA = 25˚C, VCC = ± 6V Parameter LM565 Conditions Min Power Supply Current Input Impedance (Pins 2, 3) VCO Maximum Operating Frequency VCO Free-Running Frequency −4V < V2, V3 < 0V Co = 2.7 pF Co = 1.5 nF Ro = 20 kΩ fo = 10 kHz Max 8.0 12.5 7 10 300 500 −10 0 Operating Frequency Temperature Coefficient LM565C Typ +10 Min Triangle Wave Output Voltage 2 Triangle Wave Output Linearity 1.0 2.4 3 5.4 45 50 Output Impedance (Pin 4) 500 kHz −30 0 Square Wave Rise Time 2 0.6 VCO Sensitivity fo = 10 kHz Demodulated Output Voltage (Pin 7) ± 10% Frequency Deviation Total Harmonic Distortion ± 10% Frequency Deviation Output Impedance (Pin 7) 4.25 Output Offset Voltage |V7 − V6| Temperature Drift of |V7 − V6| AM Rejection 30 Phase Detector Sensitivity KD 1.5 %/V 2.4 3 Vp-p % Vp-p 40 50 kΩ 60 20 1 0.6 300 400 0.2 0.75 200 3.5 DC Level (Pin 7) 0.2 5.4 6600 250 ppm/˚C 4.7 50 Output Current Sink (Pin 4) 4.75 30 100 4.0 % ns 50 ns 1 mA 6600 Hz/V 300 450 0.2 1.5 3.5 4.5 % 0.5 20 Square Wave Fall Time +30 5 55 mA 250 5 Square Wave Duty Cycle 12.5 −200 0.1 4.7 8.0 Units kΩ 0.2 Square Wave Output Level Max 5 −100 Frequency Drift with Supply Voltage Typ mVp-p % kΩ 4.5 5.0 V 50 200 mV 500 500 40 40 µV/˚C dB 0.68 0.68 V/radian Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is functional, but do not guarantee specific performance limits. Electrical Characteristics state DC and AC electrical specifications under particular test conditions which guarantee specific performance limits. This assumes that the device is within the Operating Ratings. Specifications are not guaranteed for parameters where no limit is given, however, the typical value is a good indication of device performance. Note 2: The maximum junction temperature of the LM565 and LM565C is +150˚C. For operation at elevated temperatures, devices in the TO-5 package must be derated based on a thermal resistance of +150˚C/W junction to ambient or +45˚C/W junction to case. Thermal resistance of the dual-in-line package is +85˚C/W. www.national.com 2 Typical Performance Characteristics Power Supply Current as a Function of Supply Voltage Lock Range as a Function of Input Voltage VCO Frequency DS007853-16 DS007853-15 DS007853-14 Oscillator Output Waveforms Phase Shift vs Frequency DS007853-17 VCO Frequency as a Function of Temperature DS007853-18 DS007853-19 Loop Gain vs Load Resistance Hold in Range as a Function of R6–7 DS007853-21 DS007853-20 3 www.national.com DS007853-1 Schematic Diagram www.national.com 4 AC Test Circuit DS007853-5 Note: S1 open for output offset voltage (V7 − V6) measurement. Typical Applications 2400 Hz Synchronous AM Demodulator DS007853-6 5 www.national.com Typical Applications (Continued) FSK Demodulator (2025–2225 cps) DS007853-7 FSK Demodulator with DC Restoration DS007853-8 www.national.com 6 Typical Applications (Continued) Frequency Multiplier (x10) DS007853-9 IRIG Channel 13 Demodulator DS007853-10 7 www.national.com Applications Information Lag-Lead Filter In designing with phase locked loops such as the LM565, the important parameters of interest are: FREE RUNNING FREQUENCY LOOP GAIN: relates the amount of phase change between the input signal and the VCO signal for a shift in input signal frequency (assuming the loop remains in lock). In servo theory, this is called the “velocity error coefficient.” DS007853-12 A simple lag filter may be used for wide closed loop bandwidth applications such as modulation following where the frequency deviation of the carrier is fairly high (greater than 10%), or where wideband modulating signals must be followed. The natural bandwidth of the closed loop response may be found from: The loop gain of the LM565 is dependent on supply voltage, and may be found from: Associated with this is a damping factor: For narrow band applications where a narrow noise bandwidth is desired, such as applications involving tracking a slowly varying carrier, a lead lag filter should be used. In general, if 1/R1C1 < Ko KD, the damping factor for the loop becomes quite small resulting in large overshoot and possible instability in the transient response of the loop. In this case, the natural frequency of the loop may be found from fo = VCO frequency in Hz Vc = total supply voltage to circuit Loop gain may be reduced by connecting a resistor between pins 6 and 7; this reduces the load impedance on the output amplifier and hence the loop gain. HOLD IN RANGE: the range of frequencies that the loop will remain in lock after initially being locked. fo = free running frequency of VCO Vc = total supply voltage to the circuit R2 is selected to produce a desired damping factor δ, usually between 0.5 and 1.0. The damping factor is found from the approximation: δ ) π τ2fn THE LOOP FILTER In almost all applications, it will be desirable to filter the signal at the output of the phase detector (pin 7); this filter may take one of two forms: These two equations are plotted for convenience. Filter Time Constant vs Natural Frequency Simple Lead Filter DS007853-11 DS007853-13 www.national.com 8 Applications Information Capacitor C2 should be much smaller than C1 since its function is to provide filtering of carrier. In general C2 ≤ 0.1 C1. (Continued) Damping Time Constant vs Natural Frequency DS007853-14 9 www.national.com Physical Dimensions inches (millimeters) unless otherwise noted Metal Can Package (H) Order Number LM565H NS Package Number H10C Dual-In-Line Package (N) Order Number LM565CN NS Package Number N14A www.national.com 10 LM565/LM565C Phase Locked Loop Notes LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. National Semiconductor Corporation Americas Tel: 1-800-272-9959 Fax: 1-800-737-7018 Email: [email protected] www.national.com National Semiconductor Europe Fax: +49 (0) 1 80-530 85 86 Email: [email protected] Deutsch Tel: +49 (0) 1 80-530 85 85 English Tel: +49 (0) 1 80-532 78 32 Français Tel: +49 (0) 1 80-532 93 58 Italiano Tel: +49 (0) 1 80-534 16 80 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. 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