A 8 Gb/s 4-PAM transmitter in 0.18 μm CMOS technology

A low power 8 Gb/s multilevel pulse amplitude modulation (PAM) transmitter is proposed. 4-PAM enables transmitter to transmit data twice more than binary signaling. Also pre-switching the output driver's current sources decrease the glitches of the output, which helps transmitter to operate at a high speed. The transmitter transmits output by current-mode instead of voltage-mode to increase switching speed of driver. The transmitter is composed of output driver, 4:1 multiplexer, and encoder. Also 2
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-1 pseudo random bit sequence (PRBS) generator was designed on-chip to provide built-in self test (BIST) operation. The transmitter is designed in 0.18mum CMOS technology and achieves 8 Gb/s, a data eye opening with a height Gt 160 mV with 1.8 V supply voltage. The output driver and entire transmitter consume only 98 mW at 8 Gb/s.