A Slew Controlled LVDS Output Driver Circuit in 0.18 μm CMOS Technology

This article presents a power-efficient low-voltage differential signaling (LVDS) output driver circuit. The proposed approach helps to reduce the total input capacitance of the LVDS driver circuit and hence relaxes the tradeoffs in designing a low-power pre-driver stage. A slew control technique has also been introduced to reduce the impedance mismatch effect between the output driver circuit and the line. The pre-driver stage shows a total input capacitance of 50 fF and also controls the voltage swing and common-mode voltage at the input of the LVDS driver output stage. This makes the operation at low supply voltages using a conventional 0.18 mum CMOS technology feasible. The output driver circuit consumes 4.5 mA while driving an external 100 Omega resistor with an output voltage swing of VOD= 400 mV, achieving a normalized power dissipation of 3.42 mW/Gbps. The area of the LVDS driver circuit is 0.067 mm2and the measured output jitter is sigmarms= 4.5 ps. Measurements show that the proposed LVDS driver can be used at frequencies as high as 2.5 Gbps where the speed will be limited by the load RC time constant.