A 15-MHz, 2.7-mm 2 Notch-Free Hybrid Magnetic Current Sensor With Feedforward Ripple Cancellation and ±0.8% Local Gain Non-Uniformity

This article proposes a hybrid magnetic current sensor achieving a 15-MHz bandwidth within a compact 2.7-mm2area. To mitigate the pole–zero mismatch inherent in the two-stage integrator topology, a dual-output Gm-C integrator with subtractor-based compensation is proposed, achieving a ±0.8% local gain non-uniformity. A wideband feedforward ripple suppression scheme cancels chopping ripple without bandwidth degradation, achieving 25-dB suppression while avoiding in-band notches common in ripple reduction loop (RRL) schemes. In addition, two active capacitor-boosting techniques enhance the effective capacitance in the DC servo loop (DCSL) and the differential difference amplifier (DDA), realizing significant passive area savings. While the Hall sensitivity drift is compensated by bias current with a positive temperature coefficient (PTC), a negative-temperature-coefficient (NTC) ground technique is proposed to stabilize the Hall-plate common-mode (CM) output. Compared with the state of the art, the proposed sensor achieves$3\times $higher bandwidth,$1.5\times $improved gain flatness, and 30% smaller chip area.