A Low-Cost RFID Regulator Insensitive to Temperature and Supply Voltage Variations

Abstract

A low-cost regulator insensitive to temperature and supply voltage variations for power management units of Radio Frequency Identification (RFID) tag chips and other batteryless devices is proposed in this paper. The commonly used regulator has poor temperature rejection ratio (TRR) and poor voltage rejection ratio (VRR). By using combination resistors and long channel transistors, the bias and regulator circuits are improved over temperature variations. A power supply rejection (PSR) enhancement branch is also added to suppress the supply noise and stabilize the bias current. The regulator is designed and fabricated in the HJTC 0.25[Formula: see text][Formula: see text]m CMOS technology. Simulation results show that this regulator achieves 0.044[Formula: see text]mV/[Formula: see text]C TRR when temperature varies from [Formula: see text]C to 70[Formula: see text]C and 1.1[Formula: see text]mV/V VRR while the supply voltage of the regulator ranges from 4 to 12[Formula: see text]V. The PSR is nearly [Formula: see text]100[Formula: see text]dB at DC. The area of this regulator is 0.102[Formula: see text]mm2 including the bias circuit. The measurement results meet simulation results well and this regulator is successfully applied in HF passive tag chips within voltage deviations of [Formula: see text] of 2.5[Formula: see text]V.