A Low-Power and High-Linear Current to Time Converter for Wireless Sensor Networks

In this letter, we describe a low power current to time converter for wireless sensor networks. The proposed circuit has some advantages of high linearity and wide measurement range. From the evaluation using HSPICE with 0.18µm CMOS device parameters, the output differential error for the input current variation is approximately 0.1µs/nA under the condition that the current is varied from 100nA to 500nA. The idle power consumption is approximately zero.