This part is a kind of semiconductor called MT8870D-1.
Function of this product has Integrated DTMF Receiver.
Manufacturers : Zarlink Semiconductor
Image and pinout :
Some of the text within the PDF file :
MT8870D/MT8870D-1 ISO2-CMOS Integrated DTMF Receiver Data Sheet Features October 2006 • Complete DTMF Receiver • Low power consumption • Internal gain setting amplifier • Adjustable guard time • Central office quality • Power-down mode • Inhibit mode • Backward compatible with MT8870C/MT8870C-1 Applications • Receiver system for British Telecom (BT) or CEPT Spec (MT8870D-1) • Paging systems • Repeater systems/mobile radio • Credit card systems • Remote control • Personal computers • Telephone answering machine Ordering Information MT8870DE 18 Pin PDIP MT8870DS 18 Pin SOIC MT8870DN 20 Pin SSOP MT8870DSR 18 Pin SOIC MT8870DNR 20 Pin SSOP MT8870DN1 20 Pin SSOP* MT8870DE1 18 Pin PDIP* MT8870DS1 18 Pin SOIC* MT8870DNR1 20 Pin SSOP* MT8870DSR1 [ ... ]