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This work presents a self-biased MOSFET threshold voltage V T0 extractor circuit. Its working principle is based on a current-voltage relationship derived from a continuous physical model. The model is valid for any operating condition, from weak to strong inversion, and under triode or saturation regimes. The circuit is MOSFET-only (can be implemented in any standard digital process), and it operates with a power supply of less than 1 V, consuming tenths of nW. Post-layout simulation results show that the extracted V T0 has an error inferior to 1.3%, when compared to the theoretical value, for a −40 to 125°C temperature range. We present variability results from Monte Carlo simulations that support the extracting behavior of the circuit with good accuracy. The occupied silicon area is 0.0076 mm2 in a 0.13µm CMOS process.

This paper presents a high-linearity and large output swing instrumentation amplifier for portable multichannel biomedical applications. It is composed of a fully differential two-stage CMOS amplifier in which a feedback provides stable signal gain that can be adjusted from 25 to 100 V/V. Additionally, a pseudo-resistive feedback combined with an appropriate input capacitive coupling provides a high-pass behavior, presenting a −3 dB cut-off frequency lower than 120 mHz. The amplifier is fully integrated in a 130 nm CMOS process, using only 0.1 mm2 of silicon area, including large matched capacitor banks. Its power consumption is 31.3 µW under a 1.5 V supply. The pre-amplifier gain reaches less than 0.02 % of THD (total harmonic distortion) for an output swing of 2 Vpp in post-layout simulations. The total input-referred noise estimated from simulations is 1.93 µVrms inside the 0.5 Hz to 500 Hz frequency range.