A 2 MHz Bandwidth Area-Efficient Multipath Hall Sensor With a Residual Ripple of 4.1 μT

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.