A 10 MHz, 2.3 mm² Hybrid Magnetic Current Sensor Using Gain–Bandwidth Decoupled DDA and Passive-Aided Bandwidth Extension

This paper presents a wide bandwidth hybrid current sensor that incorporates a wideband instrumentation amplifier (IA) in the low-frequency (LF) path and a high gain-bandwidth product (GBW) integrator in the high-frequency (HF) path. The ping-pong switched-capacitor demodulator (PPSCD) in the LF path effectively suppresses ripple while introducing negligible gain non-uniformity. A two-stage integrator topology is adopted in the HF path to extend bandwidth and reduce noise compared to its single-stage counterpart. The implementation of a DC servo loop with an attenuator around the HF integrator minimizes offset with reduced area overhead. Additional area savings are achieved by employing a gain-bandwidth decoupled differential difference amplifier (DDA), which combines signals from the LF Hall path and HF coil path, and incorporates a peripheral passive bypass path for bandwidth enhancement. The proposed design achieves a 10 MHz bandwidth in a compact 2.3 mm² area, representing a 2× bandwidth improvement and 40% area reduction compared to the state-of-the-art.