MC34118A中文资料VOICE SWITCHED SPEAKER-PHONE CIRCUIT数据手册UTC规格书

描述 Description

As a voice switched speaker-phone integrated circuit, the UTCMC34118A includes the necessary amplifiers, attenuators, leveldetectors and control algorithm.To form the UTC MC34118A’s internal circuit, there is an internalmicrophone amplifier with adjustable gain and mute control, internaltransmit and Receive attenuators (operate in a complementarymanner), level detectors at both input and output of both attenuators,and background noise monitors for both the transmit and receivechannels.The dial tone can be pretended from being attenuated by thereceive background noise monitor circuit by a dial tone detector.There are also two line driver amplifiers which can be used to form ahybrid network in conjunction with an external coupling transformer. Ahigh-pass filter can be used for other filtering functions, and especiallyto filter out 60Hz noise in the receive channel.The UTC MC34118A which requiring typically 5mA may beoperated from a power supply, or it can be powered from thetelephone line.

特性 Features

Attenuator gain range: 52dB (between Transmit and Receive) For line-powered applications : 3~6.0V low voltage operation For improved sensitivity :4-point signal sensing For Transmit and Receive paths: background noise monitors External resistors set microphone amplifier gain Mute function included Chip disable: active or standby operation During dial tone presence: dial tone detector to inhibit receive idle mode