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

circuit consists of an I and Q detector driven by a voltage

controlled 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

Dual-In-Line and Small Outline Packages

00697501

Top View

Order Number LM567H or LM567CH

See NS Package Number H08C

00697502

Top View

Order Number LM567CM

See NS Package Number M08A

Order Number LM567CN

See NS Package Number N08E

February 2003

© 2004 National Semiconductor Corporation

DS006975

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