INTRODUCTION
The KA2425A is telephone speech network integrated circuit which includes transmit amp, receive amp, side tone amp, DC loop interface function, DTMF input, voltage regulator for speech, a regulated output voltage for a dialer, and equalization circuit .

FEATURES
• Low voltage operation (1.5v : speech)
• Transmit, receive, side tone and DTMF level are controlled by external resistors
• Regulated voltage for dialer
• Loop length equalization
• MUTE function
• Linear interface for DTMF