A method for eliminating the chopper ripple and implementing the method of analog to digital converters

The present invention proposes a method for eliminating the chopper ripple and modulus of the method to achieve conversion circuit. The method of chopper signal in a cycle twice the sampling interval is half the time period of the chopper, and two sampled values ​​are made integral, summation, thereby preserving the useful signal, eliminating the residual ripple of the chopper signal . The signal amplification and analog-digital conversion circuit includes a chopper amplifier and a sigma-delta analog to digital converter in a cascaded thereafter. Analog summing function embedded within the switch structure using sigma-delta analog-digital converter using a first integrator stage chopper amplifier output signal of residual first-order shaping ripple (voltage summer ), thereby reducing ripple amplitude, analog-to weaken the impact on the conversion accuracy. Between the analog circuit does not require the chopper amplifier and an analog low-pass filter, saving power, area, simplifying the circuit design.