Patent ID: 7869312

Claim:
An apparatus for conditioning signals from an optical pickup unit (OPU) comprising: a single-ended input for coupling to a single-ended output of the OPU, if any; a first signal conditioning circuit having a first signal input coupled to the single-ended input and a first signal output; a differential input having a positive and a negative input for coupling to a differential output of the OPU, if any; a second signal conditioning circuit having positive and negative signal inputs coupled to the positive and negative inputs, respectively, and a second signal output; a digital signal processor; an output multiplexer having a first signal input coupled to the first signal output, a second signal input coupled to the second signal output, and an output coupled to an input of the digital signal processor; and a voltage source coupled to the single-ended input, the differential input, and an OPU dark level reference, whereby calibration of the first and second signal conditioning circuits is referenced to the OPU dark level reference.