A 2V, 32.13nA, fully MOSFET Voltage Limiter for Low Power Applications

Abstract

This paper presents a fully MOSFET DC voltage limiter with low current consumption. In the proposed voltage reference structure to reduce power consumption, transistors are biased in the sub-threshold region. To generate complementary to absolute temperature (CTAT) voltage in the voltage reference circuit, only a PMOS transistor is used, in which its drain, gate, and source terminals are connected together and acts as a diode that reduces the layout area occupation. To further reduce power consumption, a part of the rectifier output voltage is compared with the reference voltage by the sampling circuit. Also, four stage inverters are used as buffers to provide the I-V limiting characteristic closer to the ideal situation. The use of series pass-gate transistors in the first inverter also reduces power consumption as much as possible. The results of post-layout simulation based on 0.18μm CMOS technology depict that the suggested voltage reference circuit has a reference voltage equivalent to 0.579V with a TC of 37.2ppm/℃ in the temperature range of -50°C to 50°C. LR and PSRR attained 0.008%/V and 45dB, respectively. The output voltage and current consumption of the limiter circuit are 2V and 32.13nA, respectively. The total layout area of the proposed limiter is 3249µm2.