LM567/LM567C

Tone Decoder

General Description

The LM567 and LM567C are general purpose tone decoders

designed to provide a saturated transistor switch to ground

when an input signal is present within the passband. The cir-

cuit consists of an I and Q detector driven by a voltage con-

trolled oscillator which determines the center frequency of

the decoder. External components are used to indepen-

dently set center frequency, bandwidth and output delay.

Features

n 20 to 1 frequency range with an external resistor

n Logic compatible output with 100 mA current sinking

capability

n Bandwidth adjustable from 0 to 14%

n High rejection of out of band signals and noise

n Immunity to false signals

n Highly stable center frequency

n Center frequency adjustable from 0.01 Hz to 500 kHz

Applications

n Touch tone decoding

n Precision oscillator

n Frequency monitoring and control

n Wide band FSK demodulation

n Ultrasonic controls

n Carrier current remote controls

n Communications paging decoders

Connection Diagrams

Metal Can Package

DS006975-1

Top View

Order Number LM567H or LM567CH

See NS Package Number H08C

Dual-In-Line and Small Outline Packages

DS006975-2

Top View

Order Number LM567CM

See NS Package Number M08A

Order Number LM567CN

See NS Package Number N08E

May 1999

© 1999 National Semiconductor Corporation

DS006975

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