LM565CMDC - National Semiconductor

LM565/LM565C

Phase Locked Loop

General Description

The LM565 and LM565C are general purpose phase locked

loops containing a stable, highly linear voltage controlled os-

cillator for low distortion FM demodulation, and a double bal-

anced 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 fre-

quency divider to obtain frequency multiplication.

The LM565H is specified for operation over the −55˚C to

+125˚C military temperature range. The LM565CN is speci-

fied for operation over the 0˚C to +70˚C temperature range.

Features

n200 ppm/˚C frequency stability of the VCO

nPower supply range of ±5to±

12 volts with 100 ppm/%

typical

n0.2%linearity of demodulated output

nLinear triangle wave with in phase zero crossings

available

nTTL and DTL compatible phase detector input and

square wave output

nAdjustable hold in range from ±1%to >±60%

Applications

nData and tape synchronization

nModems

nFSK demodulation

nFM demodulation

nFrequency synthesizer

nTone decoding

nFrequency multiplication and division

nSCA demodulators

nTelemetry receivers

nSignal regeneration

nCoherent demodulators

Connection Diagrams

Metal Can Package

DS007853-2

Order Number LM565H

See NS Package Number H10C

Dual-in-Line Package

DS007853-3

Order Number LM565CN

See NS Package Number N14A

May 1999

LM565/LM565C Phase Locked Loop

Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required,

please contact the National Semiconductor Sales Office/

Distributors for availability and specifications.

Supply Voltage ±12V

Power Dissipation (Note 2) 1400 mW

Differential Input Voltage ±1V

Operating Temperature Range

LM565H −55˚C to +125˚C

LM565CN 0˚C to +70˚C

Storage Temperature Range −65˚C to +150˚C

Lead Temperature

(Soldering, 10 sec.) 260˚C

Electrical Characteristics

AC Test Circuit, T

=25˚C, V

=±6V

Parameter Conditions LM565 LM565C Units

Min Typ Max Min Typ Max

Power Supply Current 8.0 12.5 8.0 12.5 mA

Input Impedance (Pins 2, 3) −4V <V

<0V 7 10 5 kΩ

VCO Maximum Operating

Frequency C

=2.7 pF 300 500 250 500 kHz

VCO Free-Running Frequency C

=1.5 nF

=20 kΩ

=10 kHz −10 0 +10 −30 0 +30 %

Operating Frequency

Temperature Coefficient −100 −200 ppm/˚C

Frequency Drift with

Supply Voltage 0.1 1.0 0.2 1.5 %/V

Triangle Wave Output Voltage 2 2.4 3 2 2.4 3 V

p-p

Triangle Wave Output Linearity 0.2 0.5 %

Square Wave Output Level 4.7 5.4 4.7 5.4 V

p-p

Output Impedance (Pin 4) 5 5 kΩ

Square Wave Duty Cycle 45 50 55 40 50 60 %

Square Wave Rise Time 20 20 ns

Square Wave Fall Time 50 50 ns

Output Current Sink (Pin 4) 0.6 1 0.6 1 mA

VCO Sensitivity f

=10 kHz 6600 6600 Hz/V

Demodulated Output Voltage

(Pin 7) ±10%Frequency Deviation 250 300 400 200 300 450 mV

p-p

Total Harmonic Distortion ±10%Frequency Deviation 0.2 0.75 0.2 1.5 %

Output Impedance (Pin 7) 3.5 3.5 kΩ

DC Level (Pin 7) 4.25 4.5 4.75 4.0 4.5 5.0 V

Output Offset Voltage

−V

|30 100 50 200 mV

Temperature Drift of |V

−V

| 500 500 µV/˚C

AM Rejection 30 40 40 dB

Phase Detector Sensitivity K

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 func-

tional, but do not guarantee specific performance limits. Electrical Characteristics state DC andAC electrical specifications under particular test conditions which guar-

antee 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.

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Typical Performance Characteristics

Power Supply Current as a

Function of Supply Voltage

DS007853-14

Lock Range as a Function

of Input Voltage

DS007853-15

VCO Frequency

DS007853-16

Oscillator Output

Waveforms

DS007853-17

Phase Shift vs Frequency

DS007853-18

VCO Frequency as a

Function of Temperature

DS007853-19

Loop Gain vs Load

Resistance

DS007853-20

Hold in Range as a

Function of R

6–7

DS007853-21

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Schematic Diagram

DS007853-1

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AC Test Circuit

Typical Applications

DS007853-5

Note: S1open for output offset voltage (V7−V

) measurement.

2400 Hz Synchronous AM Demodulator

DS007853-6

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Typical Applications (Continued)

FSK Demodulator (2025–2225 cps)

DS007853-7

FSK Demodulator with DC Restoration

DS007853-8

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Typical Applications (Continued)

Frequency Multiplier (x10)

DS007853-9

IRIG Channel 13 Demodulator

DS007853-10

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Applications Information

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.”

The loop gain of the LM565 is dependent on supply voltage,

and may be found from:

=VCO frequency in Hz

=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.

=free running frequency of VCO

=total supply voltage to the circuit

THE LOOP FILTER

In almost all applications, it will be desirable to filter the sig-

nal at the output of the phase detector (pin 7); this filter may

take one of two forms:

A simple lag filter may be used for wide closed loop band-

width 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 fol-

lowed.

The natural bandwidth of the closed loop response may be

found from:

Associated with this is a damping factor:

For narrow band applications where a narrow noise band-

width is desired, such as applications involving tracking a

slowly varying carrier, a lead lag filter should be used. In gen-

eral, if 1/R

, the damping factor for the loop be-

comes 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

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)πτ

These two equations are plotted for convenience.

Simple Lead Filter

DS007853-11

Lag-Lead Filter

DS007853-12

Filter Time Constant vs Natural Frequency

DS007853-13

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Applications Information (Continued) Capacitor C

should be much smaller than C

since its func-

tion is to provide filtering of carrier. In general C

≤0.1 C

Damping Time Constant vs Natural Frequency

DS007853-14

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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

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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.

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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LM565/LM565C Phase Locked Loop

National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.