Patent ID: 7193457
Filing Date: 2007-03-20
Classification: G05F,H03F

Abstract:
1. A chopper-stabilized current-mode instrumentation amplifier (IA), comprising: first and second input nodes; an output node; first and second input amplifiers coupled to said first and second input nodes and arranged to produce respective currents in response to a differential input voltage applied to said first and second input nodes, said currents coupled to said output node, said IA having an associated desired gain value G, each of said input amplifiers comprising a plurality of on- and/or off-chip devices and/or structures having associated parasitic capacitances which produce respective currents when said IA is chopped that cause gain G to deviate from its desired value; and gain correction circuitry coupled to said IA and arranged to replicate at least some of said parasitic capacitances and to provide compensation currents to said IA which reduce gain errors that would otherwise arise due to said parasitic capacitances.