LM567/LM567C Tone Decoder
May 1999
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.
n
n
n
n
High rejection of out of band signals and noise
Immunity to false signals
Highly stable center frequency
Center frequency adjustable from 0.01 Hz to 500 kHz
Applications
n
n
n
n
n
n
n
Touch tone decoding
Precision oscillator
Frequency monitoring and control
Wide band FSK demodulation
Ultrasonic controls
Carrier current remote controls
Communications paging decoders
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%
Connection Diagrams
Metal Can Package
Dual-In-Line and Small Outline Packages
DS006975-1
Top View
Order Number LM567H or LM567CH
See NS Package Number H08C
DS006975-2
Top View
Order Number LM567CM
See NS Package Number M08A
Order Number LM567CN
See NS Package Number N08E
© 1999 National Semiconductor Corporation
DS006975
www.national.com