Low voltage low power current reference circuit for passive RFID applications

Abstract

Passive RFID circuits depend on low voltage low power area-efficient current references. This work presents two current source implementations using 180 nm CMOS process. Both circuits work with a minimum supply voltage of 0.8 V and with a current consumption lower than 150 nA. The first one has a positive temperature coefficient while the second one is temperature compensated. Silicon results from 10 measured samples show an average output current of 21.8 nA and 20.1 nA for the PTAT and the temperature-compensated (COMP) references, respectively. Their measured temperature variations were about 41% and 5% in temperature range of -40 to 65 °C, for the PTAT and COMP, respectively.