MC34118中文资料ARCHIVED - Voice Switched Speakerphone Circuit数据手册恩XP规格书

描述 Description

Overview The MC34118 Voice Switched Speakerphone Circuit incorporates the necessary amplifiers, attenuators, level detectors, and control algorithm to form the heart of a high quality hands-free speakerphone system.Included are a microphone amplifier with adjustable gain and MUTE control. Transmit and Receive attenuators which operate in a complementary manner, level detectors at both input and ouput of both attenuators, and background noise monitors for both the transmit and receive channels.A Dial Tone Detector prevents the dial tone from being attenuated by the Receive background noise monitor circuit.Also included are two line driver amplifiers which can be used to form a hybrid network in conjunction with an external coupling transformer.A high-pass filter can be used to filter out 60Hz noise in the receive channel, or for other filtering functions.A Chip Disable pin permits powering down the entire circuit to conserve power on long loops where loop current is at a minimim.The MC34118 may be operated from a power supply, or it can be powered from the telelphone line, requiring typically 5.0 mA.The MC34118 can be interfaced directly to Tip and Ring (through a coupling transformer) for stand-alone operation, or it can be used in conjunction with a hand-set speech network and/or other features of a featurephone. Archived content is no longer updated and is made available for historical reference only.

特性 Features

•Improved Attenuator Gain Range: 52 dB Between Transmit and Receive
•Low Voltage Operation for Line-Powered Applications (3.0-6.5V)
•4-Point Signal Sensing for Improved Sensitivity
•Background Noise Monitors for Both Transmit and Receive Paths
•Microphone Amplifier Gain Set by External Resistors - Mute Function Included
•Chip Disable for Active/Standby Operation
•On Board Filter Pinned-Out for User Defined Function
•Dial Tone Detector to Inhibit Receive Idle Mode During Dial Tone Presence
•Standard 28-Pin Plastic DIP Package and SOIC Package Available
•Compatible with MC34119 Sepaker Amplifier