Abstract: A continuous-time sigma-delta modulator includes a continuous-time sigma-delta modulation module, a data monitoring module, and an offset calibration module. The data monitoring module and the offset calibration module are added on the basis of the continuous-time sigma-delta modulation module. Based on a hardware architecture design of the offset calibration module and the data monitoring module, with reference to software data processing, an offset of a quantizer in the continuous-time sigma-delta modulation module can be pre-calibrated based on feedback of a signal-to-noise ratio of a digital signal and a preset calibration algorithm, to obtain an offset calibration digital code. Finally, the offset calibration digital code is input into the quantizer by using the offset calibration module, and the offset of the quantizer is finally calibrated based on the offset calibration digital code.

Abstract: A fourth-order feedforward compensation operational amplifier is provided. The amplifier includes a first transconductance amplification unit, a second transconductance amplification unit, a third transconductance amplification unit, a fourth transconductance amplification unit, a fifth transconductance amplification unit, a sixth transconductance amplification unit, and a seventh transconductance amplification unit. The first unit, the second unit, the third unit, and the fourth unit are cascaded in sequence to form a fourth-order operational amplifier path. The first unit, the fifth unit, and the fourth unit form a third-order operational amplifier path. The first unit and the sixth unit form a second-order operational amplifier path. The seventh unit forms a first-order operational amplifier path.