A precision, mixed-signal amplifier uses correlated double sampling, a mixed-signal tracking loop, and constant-g m biasing, and provides both analog and digital outputs. Its integrated g m /C oscillator has a frequency stability of 8 ppm/°C from 25-200 °C. A fully differential opamp has a gain-bandwidth of ~30 MHz and open-loop gain that varies by just 1 dB from 25-200°C. The overall instrumentation amplifier has selectable voltage gain up to 192 and stable performance to 275 °C.