The two new products deliver superior voice processing through a variety of features including speech circuits that deliver enhanced voice switching and background noise monitoring with softclipping, line loss compensation and receiving-volume control for both handset and handsfree operations. The AS2523 and AS2524 incorporate DC and AC line adaptation through a programmable DC-mask enabling low noise of: <= -72dBmp and a synthesised AC-impedance of 1000 Ohm.

Ideal for phones that feature a handsfree capability, CallerID and extended displays, the AS2523 and AS2524 are compatible with industry standards ETS 300 001, TBR21, TBR38 and FCC Part68. The ICs have also been designed to interface with the most popular Taiwan-designed auto diallers provided by Winbond, UMC and others with no additional software development necessary, achieving faster time to market.

One of the major advantages of the AS2523 is a high-quality handsfree line interface for speaker and caller ID phones, with all relevant parameters software programmable via serial interface as well as being programmable via a dialler.

Both the AS2523 and AS2524 are line-powered devices. The AS2523 can be controlled by a microcontroller-based dialler via a serial interface or by a standard dialler via a parallel interface on the AS2524.

Other key features include a line/speakerphone circuit on a CMOS-IC; simple inventory - serial I/F on the AS2523 and parallel I/F on the AS2524; enhanced voice switching, and background noise monitoring. The AS2523 is transmit- and receive-gain programmable, supports digital volume control of received signals, and provides programmable adjustment of DC characteristics.

The ICs also feature dual softclipping in both handset and handsfree mode and a loudspeaker amplifier to boost sound in handsfree applications. Side tone adaptation can be selected and adjusted by external components.

Supply voltage is 3V to 5V generated internally from the applied line current and the ICs offer a supply voltage for external circuitry for logic and other devices. Automatic line loss compensation is provided on the AS2523 or AS2524B. Real and complex impedance can be selected and adjusted by external components.

With unique electromagnetic compatibility (EMC) performance and an operating range from 15mA to 100mA (down to 5mA with reduced performance), both the AS2523 and AS2524 use a typical operating current of 4mA for handset mode and 11mA for handsfree.

"These new chips have the lowest external component count and minimum overall costs in terms of bill-of-materials," said Heribert Hochrinner, Marketing Manager Wireline Phones of austriamicrosystems AG. "The same hardware can be used for several telephone models, which means that engineers can quickly and cheaply design new phones simply by making software changes."

The IC architecture of the AS2523 and AS2524 is an EMC cost-efficient design so that only a single-sided PCB is necessary in order to comply with EMC certification - no expensive coils are necessary. Design is simplified by chip-on-board modules in comparison to the alternative of integrating a variety of packaged parts. austriamicrosystems can provide a reference design of a COB daughter board on request.The new ICs are available in a 28-pin SOIC package or in dice with the same die for the AS2523 and AS2524.

About austriamicrosystems:
austriamicrosystems AG is one of the world's leading designers and manufacturers of highly integrated mixed signal IC´s. austriamicrosystems combines more than 20 years of design capabilities, product and marketing know-how with a full service silicon foundry specialised in mixed signal, RF and HV technologies. Operating worldwide with more than 800 employees, austriamicrosystems is organised in four strategic business units: Communications, Automotive, Industrial and Medical and Full Service Foundry.