A pseudo resistor with temperature self-adaptive scheme

Abstract

A temperature self-adaptive ultra-high-resistance pseudo-resistor (PR) circuit is proposed for a wide range of biomedical applications. It acts as a relatively constant resistor over a wide temperature range (−40 °C–85 °C) due to its potential to compensate for the impact of the temperature-induced current. Hence, the performance of many biomedical analog intellectual property (IP) circuits can be effectively improved with temperature variations. The proposed circuit consists of a gate-voltage-controlled pseudo-resistor and a proportional-to- absolute-temperature (PTAT) circuit. Besides, its analysis and proof of concept with the self-adaptive scheme are presented. The circuit is designed in standard 0.18 μm CMOS technology and occupies a silicon area of 18.5 × 43.7 μm². It consumes 12 nW with a single power supply of 1.8 V. The post-layout simulation results demonstrate that the proposed pseudo-resistor could adequately improve the temperature-induced resistance variation by up to 18X while consuming ultra-low power and providing relatively high-temperature independence compared to the prior art.