LM567 Datasheet, National Semiconductor

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 Diag.

n n n n n n n Touch tone decoding Precision oscillator Frequency monitoring and control Wide band FSK demodulation Ultra.

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 oscilla.