U4091B

TELEFUNKEN Semiconductors U4091B Programmable Telephone Audio Processor Description The programmable telephone audio processor U4091B is a linear integrated circuit for use in feature phones, answering machines and fax machines. 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 components necessary for amplification of signals and adaptation to the line. An integrated voice switch with loudspeaker amplifier allows handsfree or loudhearing operation. With an anti-feedback function, acoustical feedback during loudhearing can be reduced significantly. The generated supply voltage is suitable for a wide range of peripheral circuits. Features D D D D Speech circuit with anti-clipping Tone ringer interface with dc / dc converter Speaker amplifier with anti-distortion Power supply management, regulated, unregulated and a special supply for electret microphone Benefits D Savings of one piezo electric transducer D Complete system integration of analog signal processing on one chip D Very few external components D Voice switch Applications Feature phone, answering machine, fax machine, speaker phone Speech circuit Voice switch ÁÁ ÁÁ BUS Audio amplifier Loudhearing and Tone ringing MC with EEPROM/ DTMF Tone ringer Rev. A1: 12.07.1995 Preliminary Information 1 (11) U4091B Serial Bus Controlled Functions Speech circuit Ringer TELEFUNKEN Semiconductors ...