Patent ID: 7327189
Filing Date: 2008-02-05
Classification: H03F

Abstract:
1. An instrumentation amplifier comprising: a pair of operational amplifiers (op-amps), each op-amp having an output, a voltage input configured to receive an input voltage, and a feedback input; a pair of current conveying elements, each current conveying element having a sense node, wherein each one of the pair of current conveying elements is configured in a respective feedback loop between the output and the feedback input of a respective one of the pair of op-amps; a gain-setting resistive element comprising two or more gain-setting resistors coupled between the sense nodes of the current conveying elements; and a pair of multiplexers, wherein each one of the pair of multiplexers is configured to couple any selected one of the two or more gain-setting resistors between the pair of current conveying elements, and to couple the selected one of the two or more gain-setting resistors between the respective sense nodes of the pair of current conveying elements; wherein respective currents flowing through the respective current conveying elements form a differential output current, and wherein respective input voltages received by the voltage inputs of the pair of op-amps form a differential input voltage of the instrumentation amplifier.