摘要

This article describes the design of a four-channel parallel 40 Gb/s laser diode voltage driver (LDVD) circuit using 0.18-m CMOS technology.The LDVD circuit consists of input buffer stage, preamplifier stage, and output driver stage. The LDVD uses dual power supplies, including the 1.8-V supply in the preamplifier stage and the 3.5-V supply in the output driver stage. To increase the bandwidth, the preamplifier stage is made up of two-stage cascaded differential amplifiers. The output driver circuit uses the RC negative feedback and capacitively coupled current amplifier (C3A) structure to speed up the operation of laser diode. The isolation has been carefully taken to avoid the cross-talk issues among channels. Experimental results show that each channel of the LDVD can work at 10 Gb/s rate, and the output current swing is over 10 mA. The total power dissipation is 450 mW, and the chip area is 460 x 1230 m2.

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