A 1.25 Gb/s laser diode driver with pulse width optimization

A 1.25 Gb/s laser diode driver(LDD)with pulse width optimization has been implemented in a 0.6-μm BiCMOS process.This paper illustrates the relation between the pulse width distortion(PWD)of the output eye diagram and the driving amplitude from the second pre-amplifier.Also,a specific current setting circuit working together with an LDD is proposed to generate the optimum driving amplitude and to avoid device nonlinearity,temperature variation and process deviation.The measured results show a maximum crossing deviation of-3% and indicate the desired independence and stability.