Current-mode instrumentation amplifier gain error correction circuitry

摘要

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.