A micro current, modulated current feedback chopper instrumentation amplifier

The present invention belongs to the technical field of amplifiers, one operating at a particular micro quiescent current chopping modulation current feedback instrumentation amplifier. The amplifier consists of a DC blocking capacitor, chopping current feedback amplifier, N-bit capacitor array mismatch compensation, the ripple cancellation circuit, bias circuit and a clock divider circuit. Having an AC coupled, high input impedance, low offset voltage, low noise, high common mode rejection ratio, a high power supply rejection ratio and a micro-power characteristics; circuit is particularly suitable for wearable health care system biopotential electrode collecting dry circuit, can rail to rail elimination half offset potential between the electrodes. A case of the embodiment of the present invention, simulation results show that the instrumentation amplifier common mode rejection greater than 120dB, equivalent input impedance is greater than 500M ohms, the noise energy efficiency factor NEF = 4.5.