HM9270 Integrated DTMF Receiver - (AD54266)

Description:

The HM9270C /D is a full DTMF receiver that integrates both the band-split filter and digital decoder functions. The filter section uses switched capacitor techniques for both high and low group filters and dial tone rejection. Digital counting techniques are employed in the decoder to detect and decode the 16 DTMF tone pairs into a 4-bit code. External component count is minimized by the on-chip provision of a differential input amplifier, clock oscillator, and latched 3-state bus interface.

Datasheet