103_COMPATIBLE_MODEM

Published:2009/7/14 4:46:00 Author:May | From:SeekIC

Motorola 4412IC converts serial data, usually to and from uni-versal asynchronous receiver-transmitter, into tones suitable for telephone communication. In originate mode, logic0 is transmitted as 1070 Hz and logic 1 as 1270 Hz. In answer mode, logic 0 is transmitted as 2025 Hz and logic 1 as 2225Hz. Modems are used in pairs, with receiver responding to tone group not being transmitted. Speed capability is up to 300-baud data rate. Output is 300 mVRMS into 100k load.-D. Lan-caster, CMOS Cookbook, Howard W. Sams, Indianapolis, IN, 1977, p 133.



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