The Microchip Technology MT9171AP1 is a telecom interface IC designed for high-speed digital transmission. It operates on a single 5V supply and is housed in a 28-PLCC package.
The Microchip Technology MT9172AP1 is a Digital Subscriber Interface Circuit designed for telecom applications. It operates with a 4.75V to 5.25V supply and a temperature range of -40°C to 85°C.