Improving the performance of direct interface circuits using the Vernier technique

This paper proposes the use of Vernier technique to improve the performance of direct interface circuits based on measuring the charging or discharging time of an RC circuit that includes the sensor. The proposed Vernier technique either improves the resolution determined by quantization of the digital timer or reduces the cost, measuring time, and power consumption of the circuit while preserving the same resolution, which is very attractive for autonomous sensors. Experimental tests carried out by an MSP430F123 microcontroller show the effectiveness of such a technique.