Abstract: In one embodiment, a current source circuit having a reference resistor produces first, second and third bias currents that vary with manufacturing variances of the current compensation resistor. An input amplification stage includes a transconductance stage biased by the first bias current, a first transimpedance amplifier (TIA) biased by the second bias current, and a first feedback resistor coupled between the first TIA's input and output. The input of the first TIA is coupled to an output of the transconductance stage. An output amplification stage is biased by the third bias current and has an input coupled to an output of the first TIA. A second feedback resistor is coupled between the output of the output amplification stage and the input of the transconductance stage. The reference resistor and first and second feedback resistors are formed using a common manufacturing process.