AS2524B

austriamicrosystems Telephone Line Interface and Speakerphone Circuit AS2523, AS2524, AS2524B Key Features - PRELIMINARY DATA SHEET General Description AS2523/24 is a CMOS integrated circuit that incorporates DC and AC line adaptation (DC-mask and synthesized ACimpedance of 1000 Ω ) as well as a speech circuit with softclipping, line loss compensation and Rx-volume control for handset and handsfree operation. It shall act as an a/bline powered device, which is controlled by a CPU via a serial interface on AS2523 or a standard dialler via a parallel interface on AS2524 and AS2524B. Line/Speakerphone circuit on a 28-pin CMOS-IC, simple inventory: same die for AS2523/24 and AS2523/24B Serial I/F on AS2523, parallel I/F on AS2524 Enhanced voice switching Background noise monitoring Tx- and Rx-gain programmable on AS2523 only Digital volume control of Rx signals on AS2523 only DC characteristic programmable on AS2523 only Dual softclipping in handset mode on AS2523 only Dual softclipping in handsfree mode on AS2523 only Loudspeaker amplifier for loudhearing and handsfree Supply voltage generation for external circuitry Automatic line loss compensation on AS2523 / 24B only Real and complex impedance selectable by external components Side tone adaptation selectable by external components Unique EMC performance Operating range from 15mA to 100mA (down to 5mA with reduced performance) Few external components Applications Enhanced handsfree feature phones with CallerID and extende...