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Semiconductor
MSM7715
1/21
Multi-Function Telecommunication LSI
GENERAL DESCRIPTION
The MSM7715 is a signal transmitting and receiving LSI device for applications such as
telemeters. The MSM7715 uses a no-ringing communication mode. Built-in functions includes
a 300 bps full-duplex modem complying with ITU-T V.21, a DTMF signal (PB signal) generator
and receiver, and a call progress tone (CPT) detector. The answer tone (1650 Hz) generation can
be accomplished with the built-in modem.
A meter terminal can be configured using this transmitting and receiving device along with the
meter, NCU, and controller.
FEATURES
3 V power supply. (Voltage range is 2.5 V to 3.6 V.)
Selectable modes, including DTMF signal sending mode, DTMF signal receiving mode, and
V.21 modem answer/originate mode.
For DTMF signal reception, support for normal detection mode or high-speed detection mode.
For call progress tone detection, support for rectangular wave output or detection output.
DTMF signal receiving output, which is in a 3-state mode, is able to be connected externally
with the DTMF signal sending 4-bit input.
Analog loopback test and remote digital loopback test supported.
Dedicated pins for modem sending/receiving data, carrier detection, sending request, and call
progress tone detection.
Independent external adjustment of the analog signal using the modem signal and DTMF
signal.
External adjustment of the carrier detection level.
Internal 3.579545 MHz crystal oscillation circuit.
Power-down mode
Package:
44-pin plastic QFP (QFP44-P-910-0.80-2K)
(Product name : MSM7715GS-2K)
E2A0030-16-X1
This version: Jan. 1998
Previous version: Nov. 1996