IEEE Journal of Solid-State Circuits · 1993 · 100 citations · 8 references
EngineeringElectrical EngineeringAnalog ElectronicsInstrumentationMicroelectronicsAnalog InstrumentationAnalog Integrated CircuitsAnalog IntegrationFeedback AmplifiersInstrumentation AmplifiersNoise In Analog CircuitsCommon-mode RejectionCurrent Feedback AmplifiersCurrent-feedback Instrumentation AmplifierInput Common-mode RangeInput Offset VoltageInstrumentation AmplificationInstrumentation Amplifier DesignOffset Voltage
An instrumentation amplifier which can handle common-mode voltages that extend 200 mV below the negative supply is presented. The extended range is combined with a common-mode rejection of 92 dB and an accuracy of 0.1%, without the need for on-chip trimming. This has been achieved by the use of two p-n-p V-to-f converters in an indirect current feedback configuration. The output voltage can reach the negative supply. The offset voltage is 0.3 mV, and the noise voltage is 30 nV/ square root Hz. The circuit operates at supply voltages down to 2.5 V, and the quiescent current is 240 mu A. The instrumentation amplifier has been integrated in a semicustom bipolar process.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
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