Current Sensing Front-Ends: A Review and Design Guidance

Sensors link the physical and electronic worlds, finding uses in environmental, automotive, industrial, communication, and medical applications, among many more. Here, current-output sensors and current-sensing front-ends are reviewed, aiming to provide readers comprehensive design guidance from both sensor and circuit perspectives. Starting from the transduction method, capacitive, resistive, diode/FET-based, and MEMS sensors are individually reviewed with a focus on applications, circuit models, and nonidealities that must be considered for the front-end design. This is followed by a discussion of current-sensing front-ends, including transimpedance amplifiers (TIAs), current conveyors (CC), current-to-frequency ( ${I}$ -to- ${F}$ ) converters, and current-mode delta-sigma (I- $\Delta \Sigma $ ) modulators. Each front-end is analyzed in terms of gain, bandwidth, stability, noise, and general design considerations are presented. State-of-the-art works for each front-end are then reviewed, and tradeoffs between different architectures are discussed.