A digital-to-resistance converter with an automatic offset calibration method for evaluating dynamic performance of resistive sensor readout circuits

In this paper, a digital-to-resistance converter (DRC) with automatic offset calibration circuits is proposed. This circuit is used to evaluate the dynamic performance of resistive sensor readout circuits. The proposed DRC consists of a digital-to-analog converter, an analog multiplier, a fixed-value reference resistor, and current sources. A wide-range resistance changing at high frequency is achieved with the proposed DRC. In order to minimize the resistance error caused by the offset voltage of op-amps, an automatic offset calibration method is proposed. This developed prototype DRC achieved 96.3 dB dynamic range, 56.1 dB SNDR at 10kHz, and a maximum operating frequency is 100kHz.