Low Voltage, High Precision FVF based Current Differencing Circuit

This paper introduces a novel current differencing circuit based on a flipped voltage follower (FVF) architecture. The design incorporates an FVF-based current mirror to achieve wide-range current mirroring. It integrates a Wilson current mirror for negative feedback, ensuring a stable output current with minimal differencing error over an extended linear input range. To further enhance performance, modified FVF blocks are employed at the input stages, reducing input resistances at the n and p terminals to 0.056Ω and 0.059Ω, respectively, while achieving a high output resistance of 166MΩ. The proposed circuit operates efficiently across a ±100μA input range with a percentage error below ±1.79%. The present work has been designed and simulated in the Cadence Virtuoso Analog Design Environment (ADE) using UMC 180nm CMOS technology with a ±0.6 V dual power supply. This circuit is well-suited for applications in high-precision analog signal processing, biomedical instrumentation, and sensor interface circuits, where accurate current differencing is essential.