A multi-path CMOS Hall sensor with integrated ripple reduction loops

Abstract

This paper describes a multi-path Hall sensor intended for wide-bandwidth current sensing. The spinning-current technique and on-chip ripple reduction loops are used to suppress the offset and spinning ripple, respectively, of a set of Hall sensors in a low frequency path. More bandwidth is achieved by combining this path with a high frequency path consisting of a second set of non-spun Hall sensors. The proposed system is realized in a 0.18μm CMOS process. It achieves 40 μT residual offset in a bandwidth of 400 kHz, which represents a 40× improvement on the state-of-the-art.