AF121 Datasheet - National Semiconductor

AF121 DTMF Bandpass Filters

The AF121 and AF122 are 6th order elliptic bandpass filters designed for use with digital DTMF detectors. These filters are compatible with tone detector circuits such as the Rockwell CRC8030 and the Mostek MK5102 DTMF digital receivers. The filters provide 40 dB separation between the high and low .

AF121 Features

* Compatible with Rockwell CRC8030 and Mostek MK5102

* Gain o±0.5 dB

* Ripple 2 dB peak to peak

* Input Impedance 175 kn min

* Power Supply ±5V to ±18V Connection Diagram Dual-In-Line Package INPUT VTOP VIEW GND Unspecified pins are for interna

AF121-NationalSemiconductor.pdf