Means/method for generating a laser drive signal

摘要

A driver for driving a light generator for generating light, comprising a digitalto-analog converter (DAC) having a data input, a data output for generating an analog signal, a first multiplexer (MUX 1 ) for cyclic selection of a number of data levels corresponding to desired intensity levels of the light and for coupling the data levels to the data input; a de multiplexer (DE-MUX) synchronized with the first multiplexer (MUX1) for de-multiplexing the analog signal into a set of analog signals; memory means for temporarily storing the set of analog signals; and a second multiplexer (MUX 2 ) for selection of the stored set of analog signals and for generating a drive signal (IL) for the light generator. The memory means is preferably implemented by a set of capacitors (C 1 -C 8 ). Usually, for instance in an optical disc drive, the light generator is implemented by a laser (L_s). In this situation the data input of the digital-to-analog converter comprises a threshold data input part; a delta data input part; a threshold gain reference input associated with the threshold data input part; and a delta gain reference input associated with the delta data input part. So in fact the DAC is split into two parts (DAC 1 and DAC 2 ) for separate threshold power and delta power control of the laser (LS).