A 2-Gb/s CMOS SLVS Transmitter with Asymmetric Impedance Calibration for Mobile Interfaces

Abstract

A scalable low voltage signaling (SLVS) transmitter, with asymmetric impedance calibration, is proposed for mobile applications which require low power consumption. The voltage swing of the proposed SLVS transmitter is scalable from 40 mV to 440 mV. The proposed asymmetric impedance calibration asymmetrically controls the pull-up and pull-down drivers for the SLVS transmitter with an impedance of 50 Omega. This makes it possible to remove the additional regulator used to calibrate the impedance of an output driver by controlling the swing level of a pre-driver. It also maintains the common mode voltage at the center voltage level of the transmitted signal. The proposed SVLS transmitter is implemented using a 0.18-mu m 1-poly 6-metal CMOS process with a 1.2-V supply. The active area and power consumption of the transmitter are 250 x 123 mu m(2) and 2.9 mW/Gb/s, respectively.