MSM7557

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)

Pinout




Specifications

Symbol	Parameter	Conditions	Limits	Unit
VDD	Power Supply Voltage	Ta = 25°C Refer to GND	_0.3 to 7	V
VIA	Analog Input Voltage *1		0.3 to VDD + 0.3	V
VID	Digital Input Voltage *2		0.3 to VDD + 0.3	V
TSTG	Storage Temperature	-	55 to +150	°C

*1 : LIM, VR2, TVI, RAI, CMPI
*2 : SD, EMP, DYN, SEC, RCK1, RCK2, BYP, BR, FDE, BIT, FPS, RVE, PDN, X2, ME, TVE


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 MSM7557 consists of Band pass filter, De-emphasis and Expander.