A Temperature Variation Tolerant CMOS-Only Voltage Reference for RFID Applications

In this paper a reference voltage circuit is presented for outdoor RFID applications. The circuit consists of a Dickson charge pump and a series of stacked diode connected CMOS devices. With this configuration we have introduced a new approach to produce a 1.515V reference voltage from a Dickson charge pump which shows robust behavior against temperature variation. Taking advantage of a harvested RFID signal rendered the circuit suitable for a wide range of applications in which energy and area constraints are of great concern. The circuit has been designed with conventional CMOS devices using a commercial 40nm technology and simulated with cadence. The proposed circuit consumes 235nW power with 88 PPM/°C temperature coefficient in temperature range of -10°C to 125°C. The total active area of the circuit is 0.00036mm². The circuit shows +10% -12% variation from the nominal value due to process corner analysis and its PSRR(dB) is -47©915MHz.