5 Gbps 0.35-μm CMOS driver for laser diode or optical modulator

This paper presents a versatile driver for laser diode or optical modulator using a 0.35-μm CMOS process. In this driver, a quasi push-pull source follower is introduced. Combined with a dynamic amplification technique, the driver´s slew rate and output voltage swing are increased; meanwhile the overshoot is efficiently reduced. The driver works well at 2.5 Gbps under 3.3 V and 5 V supply voltage, consuming typical power of 310 mW and 945 mW respectively. It can give a modulation voltage (with 50-Ω load) ranging from 0.55 V_P-P to 4.2 V_P-P under 3.3 V supply voltage and 0.6 V_p-p to 6.2 V_P-P under 5 V supply voltage, therefore it can be used as a laser diode or optical modulator driver. When the driver was tested with a LiNbO₃ modulator, clear optical eye diagrams were measured at 2.5 Gbps and 5 Gbps, respectively. The die area is 0.57 mm².