This paper presents a multipath wide-bandwidth magnetic current sensor based on Hall effect. To simultaneously achieve wide bandwidth, minimal ripple and small area, the system incorporates a non-spun filter-free main path with offset elimination through a continuous-time compact auxiliary path. The auxiliary path cancels the main path offset via feedforward, alleviating the need for area-consuming blocking capacitor or DC servo loop. Therefore, the chip occupies only 1.52 mm2. To suppress ripple in the auxiliary path induced by spinning current, a ping-pong switch-capacitor (PPSC) filter is proposed which mitigates ripple by sampling and averaging in the forward path, with the system achieving a residual ripple of$4.1~{\mu }$T. Compared with the state-of-the-art Hall sensor, it achieves$5{\times }$bandwidth improvement,$2{\times }$ripple reduction while occupying$5{\times }$less area.

In this paper, an RC relaxation oscillator exhibiting robust performance over an extended temperature and supply range is proposed. By incorporating a digitally-assisted calibration loop, the design eliminates the errors from switch on-resistance, comparator offset and propagation delay. Fabricated using a 180 nm bipolar-CMOS-DMOS (BCD) process technology, the oscillator operates at a frequency of 7MHz with the supply sensitivity of 870 ppm/V across a voltage range of 1.7 to 4.2 V. The evaluation of 40 untrimmed samples achieved an average temperature coefficient (TC) of 52 ppm/$^{\circ}$C from$-$40$^{\circ}$C to 165$^{\circ}$C, with the worst observed TC being 81 ppm/$^{\circ}$C. The aging test results indicate small deviations of 0.3% and 11% in the oscillation frequency and its TC, respectively. Furthermore, the direct power injection test confirms its reliability and robustness with a maximum error of oscillation frequency of 6.4%.

This paper presents a RC relaxation oscillator with wide temperature range for automotive application. By using a digitally assisted calibration loop, the comparator offset and the loop delay are efficiently cancelled. With both reference voltage and current derived from the same ΔVBE-based bias circuit, the proposed design cancels leakage currents and makes the design insensitive to high-temperature. The oscillator was fabricated in a 180 nm BCD process, the oscillator operates at 7MHz and achieves a supply sensitivity of 870 ppm/V from 1.7 to 4.2 V at room temperature. Measurements on 40 samples without trimming show that it has an average temperature coefficient of 52 ppm/°C over a wide temperature range (-40°C to 165°C), with the worst case temperature coefficient of 65 ppm/°C.

A novel continuous-time level-crossing analog-to-digital converter (LC-ADC) for biomedical application is proposed. Lower power consumption and less design complexity with respect to the conventional designs are achieved due to 1) replacing the n-bit digital-to-analog converter (DAC) with a 1-bit DAC; 2) introducing a 3-input comparator and switching off the idle branches in the following stages when possible; 3) utilizing the opposite polarity of the differential input signals and fixing the comparison window with only one reference level; 4) splitting the level-crossing detections. Designed to be implemented in 0.18 µm CMOS technology, the proposed ADC achieves 8 bits of resolution with much lower power consumption than conventional LC-ADCs.