Current Sensing Front-Ends: A Review and Design Guidance
Da Ying, Drew A. Hall
Abstract
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 ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}$ </tex-math></inline-formula> -to- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${F}$ </tex-math></inline-formula> ) converters, and current-mode delta-sigma (I- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Delta \Sigma $ </tex-math></inline-formula> ) 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.