Datasheet Summary
Programmable Telephone Audio Processor
Description
The programmable telephone audio processor U3900BM is a linear integrated circuit for use in feature phones, answering machines, fax machines and cordless phones. It contains the speech circuit, tone-ringer interface with DC/DC converter, sidetone equivalent and ear-protection rectifiers. The circuit is line-powered and contains all ponents necessary for signal amplification and adaptation to the line. The U3900BM can also be supplied via an external power supply. An integrated voice switch with loudspeaker amplifier enables hands-free or loudhearing operation. With an anti-feedback function, acoustical feedback during...