Digitally programmable instrumentation amplifier offers autozeroing

摘要

The current trend in advanced instrumentation amps is to use no external resistors. In these amplifiers, a gain-control word, comprising a binary-coded one, sets the voltage gain. Several integer gains within one to 1000 are currently available; however, this range does not yet include a gain of three. Although external-resistor-free amplifiers with a gain of three are available, they are neither instrumentation amps nor autozeroed devices (Reference 1). These features are essential in applications requiring accurate processing of low-level voltages. You can use the circuit in Figure 1 for applications requiring instrumentation amps having voltage gains of three or 10 and the ability to process voltages as low as 1 mV.