This work presents an energy-efficient diode-based CMOS temperature sensor. It is based on the capacitively biased diode (CBD) working principle and can operate with a 1-V supply voltage. Instead of using a separate CBD front-end and ADC, a new architecture is proposed in which the CBD front-end is directly embedded into the 1st stage of a 1-bit 2nd-order switched-capacitor ΣΔ-ADC, thereby improving both energy efficiency and accuracy. The circuit was fabricated in a standard 55-nm CMOS process and occupies an active area of 0.021 mm². The measured inaccuracy is ±0.6 °C (3σ) from -55 °C to 125 °C after a 1-point calibration. Furthermore, it consumes 2.2 μW and achieves a resolution of 15 mK in a conversion time of 6.4 ms, which corresponds to a competitive resolution FoM of 3.2 pJ·K²

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This book is based on the 18 invited tutorials presented during the 27th workshop on Advances in Analog Circuit Design. Expert designers from both industry and academia present readers with information about a variety of topics at the frontiers of analog circuit design, including the design of analog circuits in power-constrained applications, CMOS-compatible sensors for mobile devices and energy-efficient amplifiers and drivers. For anyone involved in the design of analog circuits, this book will serve as a valuable guide to the current state-of-the-art.

Provides a state-of-the-art reference in analog circuit design, written by experts from industry and academia;

Presents material in a tutorial-based format;

Covers the design of analog circuits in power-constrained applications, CMOS-compatible sensors for mobile devices and energy-efficient amplifiers and drivers@en

This paper presents an active electrode system for gel-free biopotential EEG signal acquisition. The system consists of front-end chopper amplifiers and a back-end common-mode feedback (CMFB) circuit. The front-end AC-coupled chopper amplifier employs input impedance boosting and digitally-assisted offset trimming. The former increases the input impedance of the active electrode to 2 G at 1 Hz and the latter limits the chopping induced output ripple and residual offset to 2 mV and 20 mV respectively. Thanks to chopper stabilization, the active electrode achieves 0.8 μVrms (0.5-100 Hz) input referred noise. The use of a back-end CMFB circuit further improves the CMRR of the active electrode readout to 82 dB at 50 Hz. Both front-end and back-end circuits are implemented in a 0.18 μm CMOS process and the total current consumption of an 8-channel readout system is 88 μA from 1.8 V supply. EEG measurements using the proposed active electrode system demonstrate its benefits compared to passive electrode systems, namely reduced sensitivity to cable motion artifacts and mains interference.@en