Patent ID: 6392215
Filing Date: 2002-05-21
Classification: H01S

Abstract:
A circuit for driving a laser diode, comprising:a current source coupled to said laser for biasing said laser; an operational amplifier having a high impedance output coupled to said current source for driving said current source, said operational amplifier having a first and a second input, said first input being coupled to a reference voltage, said second input for receiving a feedback signal; a light sensing device coupled to a first supply voltage for detecting an optical power output from said laser, said light sensing device generating a monitor current proportional to said detected optical power output; a current mirror coupled to said light sensing device and said second input of said operational amplifier, said current mirror for receiving said monitor current and for generating a mirror current, said mirror current being substantially equal to said monitor current; a constant current source coupled to said second input for outputting a reference current, said reference current and said mirror current being utilized to generate said feedback signal; and a capacitor coupled between said output of said operational amplifier and a ground potential that filters said output and functions as a dominant pole for frequency compensation.