GENERAL DESCRIPTION

The MSM7557 is a single chip MSK modem with base band voice processor for cordless telephone. The MSM7557 voice transmit block consists of high pass filter, compressor, pre-emphasis, limiter and splatter filter.

Voice receive block consists of Band pass filter, De-emphasis and Expander.

FEATURES

• Available to transmit modem signal and also transmit base band voice signal through wireless transmission path (0.3 kHz to 3.4 kHz)

• Built-in compandor circuit• Upper limit of voice band (3306 Hz/3400 Hz/3500 Hz) is selectable

• Modem bit rate (2400/1200 bps) is selectable

• Transmit function and receive function operate separately

• Emphasis mode selectable

• Built-in bit synchronous detector and frame synchronous detector

• Built-in limiter level generator and external limit voltage input• Dynamic range selectable

• Built-in crystal oscillator circuit• Wide range power supply voltage (2.7V ~ 5.5V)

• Package : 56-pin plastic QFP (QFP56-P-910-0.65-2K) (Product name : MSM7557GS-2K)