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
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