Description
The U4030B is an electronic speech circuit for standard and feature telephones. It replaces the hybrid transformer, earphone and microphone interface and the supply voltage generation for external components, e.g. dialer or microcomputers. Using the U4030B in telephone circuit designs can improve transmission quality and results in cost savings through shorter and more flexible design procedures. It reduces the amount of external components needed. The U4030B uses TEMIC’s reliable bipolar technology and is offered in a SO20 package.

Features
●  Microphone amplifier with
    – Symmetrical input
    – Privacy function
    – Anticlipping
● Built in ear protection
● Power down input
● Mute input
● DTMF interface
● Low line impedance during pulse dialing

Benefits
● Independent adjustment of
    – Transmission gain
    – Receiving gain
    – Sidetone suppression
    – Frequency response
● Low-impedance supply voltage for all external blocks
● Supply voltage for an electret microphone

Applications
● Standard telephone
● Fax machine
● Answering machine
● Cordless telephone