A Low Power Front-End for Resistive Sensors based on Switch-Cap Current Reuse

This paper presents a simple, low-power switch-capacitor front-end for resistive sensors made of a capacitor and two switches. The front-end reuses the current in the circuit by storing it in the first half period of the clock and releases it in the next. When combined with a pair of differential resistive sensors connected as a voltage divider, the average power consumption reduces to 50%. The front-end can further reduce the power consumption of a single resistive sensor connected in a simple voltage divider. The average reduction of power consumption follows the duty cycle of the clock. We show that for a single resistor, the average power is reduced to 10% when a clock with 10% duty cycle is applied. The presented concept is proven by simulation and measurement.