This paper presents a sigma-delta interface for fluxgate sensor based on a single-loop high-order modulation. A feedforward summation loop structure can reduce the linearity overload in integrators and the swing of integration signals. A Local feedback branch is proposed to realize the zero of noise transfer function (NTF) optimization and enhance noise shaping performance within signal band. The interface is fabricated in a standard 0.5 $\mu$m CMOS process and the active circuit area is about 13 mm². The chip consumes 120 mW from a 10 V supply with a sampling clock of 250 k Hz. The average noise floor of the digital fluxgate is about −115 dBV/Hz${}^{1/2}$ over a 100 Hz bandwidth.

本文提出了一种基于单环高阶调制的磁通门传感器的sigma-delta接口。前馈求和环路结构可以减少积分器的线性过载和积分信号的摆动。提出了一种局部反馈支路，以实现零噪声传递函数（NTF）优化，并增强信号频带内的噪声整形性能。接口以标准0.5制成 $\mu$m CMOS工艺，有源电路面积约为13 mm ²。该芯片从10 V电源消耗的功耗为120 mW，采样时钟为250 k Hz。数字通量门的平均本底噪声约为-115 dBV / Hz${}^{\mathrm{1个}/2}$ 在100 Hz带宽上。