Patent ID: 7808872
Filing Date: 2010-10-05
Classification: G11B

Abstract:
1. A hybrid laser diode driver (LDD) for driving a laser diode in response to receiving enable signals from a controller that is external to the hybrid LDD, the hybrid LDD comprising: a read channel to output a read current; a write channel to selectively output a write current; an oscillator channel to output an oscillator current; and a state machine that receives the enable signals from the controller, and based on the enable signals, controls timing of the currents output by the write channel; and registers to store amplitude values for the write channel; wherein the state machine is configured to produce a plurality of different outputs corresponding to a plurality of different states of the state machine; wherein the state machine is configured to change from a present state to a next state based on the present state and the enable signals received from the controller, to thereby change from producing a present output to a next output; wherein the write channel includes a write digital-to-analog converter (DAC); wherein outputs of the state machine select which and when amplitude values stored in the registers are provided to an input of the write DAC of the write channel to thereby control the amplitude and the timing of the write current output by the write channel; wherein the read current output by the read channel, the write current output by the write channel and the oscillator current output by the oscillator channel are summed together to provide a current for driving the laser diode.