Abstract: A chopper-stabilized current-mode instrumentation amplifier comprises first and second input amplifiers coupled to respective input nodes and arranged to produce respective currents in response to a differential input voltage applied to the input nodes; the currents are coupled to an output node. To reduce gain errors that might otherwise arise due to the parasitic capacitances of the on- and/or off-chip devices and/or structures making up the input amplifiers, the invention includes gain correction circuitry coupled to the IA. The gain correction circuitry replicates at least some of the parasitic capacitances, and provides compensation currents to the IA which reduce both input- and output-referred gain errors that might otherwise arise.

Abstract: A chopper-stabilized current mirror includes a pair of FETs connected to mirror an input current Iin. In one embodiment, switching networks S1 and S2 have their respective inputs connected to the FETs' drains, and are operated with clock signals CLK1 and CLK2, respectively. An ro boost amplifier A12 has its inputs connected to the outputs of S2 and its outputs connected to the gates of a pair of cascode FETs via a switching network S3 which is operated with clock signal CLK2S, with the drain of one cascode FET connected to Iin and the drain of the other providing the mirror's output Iout. S1 is clocked to reduce mismatch errors and S2 and S3 are clocked to reduce errors due to A1's offset voltage, with CLK2 and CLK2S shifted with respect to CLK1 to reduce errors due to parasitic capacitances.