A CMOS modem analog processor for V.22 bis modems

A mixed analog/digital chip that forms the core of a medium-speed modem for use on the public switched telephone network is described. It meets CCITT and AT&T requirements for data transmission at 2400 and 1200 b/s, and the AT&T requirement for 300-b/s operation. The chip is implemented in a 1.75- mu m analog CMOS process and occupies 32.4 mm/sup 2/. The device is powered by a single +5-V supply and consumes less than 115 mW. The architecture and circuit implementation are described, and experimental results are given.<
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