HM9270 DTMF Receiver

The HM 9270D is a complete DTMF receiver integrating both the bandsplit filter and digital decoder functions. The filter section uses switched capacitor techniques for high- and low-group filters and dial-tone rejection. Digital counting techniques are employed in the decoder to detect and decode all 16 DTMF tone-pairs into a 4-bit code. External component count is minimized by onchip provision of a differential input amplifier, clock-oscillator and latched 3-state bus interface.

Features
* Complete receiver in an 18-pin package.
* Excellent performance.
* CMOS, single 5 volt operation.
* Minimum board area.
* Central office quality.
* Low power consumption.
* Power-Down mode (HM9270D only).
* Inhibit-mode (HM9270D only).