MSM7715

E2A0030-16-X1 ¡ Semiconductor MSM7715 ¡ Semiconductor Multi-Function Telecommunication LSI This version: Jan. 1998 MSM7715 Previous version: Nov. 1996 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. Ext...