Design Of Picowatts-level CMOS Voltage Reference With High Performance

With the rapidly development of the Internet of Things and portable electronics,the demand of low power consumption is increasing to extend system lifetime and reduce battery size.Sensing systems such as biomedical implants,radio frequency identification,and military surveillance units are constrained to consume only picowatts to nanowatts in standby and active mode,respectively.This tight power budget places ultra-low power demand on all building blocks in the systems.In the building blocks(ADC,DAC,and LDO)of ultra-low power portable systems,voltage references play a key role in overall system performance and greatly contribute to standby power consumption.Thus,the voltage references in ultra-low power portable systems are devoted to the design of ultra-low power consumption.This paper presents three picowatts-level voltage reference circuits based on standard CMOS technology.The design of the picowatts-level voltage reference with excellent performance of line regulation and power supply rejection ratio(PSRR),based on standard CMOS technology,is emphatically pointed out in this paper.The article begins with an analysis of the four traditional picowatts-level reference circuits in the current research field.By analyzing the performance of these four circuits,two important conclusions about the traditional picowatts-level reference circuits are obtained.Compared to conventional bandgap reference circuits,the traditional picowatts-level reference circuits have superior performance in terms of power consumption and area,but poor perform in terms of temperature stability,line regulation,and PSRR;the implementation of the current traditional picowatts-level reference circuits rely on special process technology,which is an important factor limiting its widespread application in ultra-low power IoT systems.Then,aiming at the weaknesses of the traditional picowatts-level reference circuits,a novel picowatts-level reference circuit is proposed in this paper.By combining the basic principle of bandgap reference and traditional picowatts-level reference,a new type of pico-level reference circuit model is presented.Based on this circuit model,the proposed voltage reference is not only compatible with standard CMOS technology,but also achieves 33.3 pW power consumption and good temperature stability(32.7 ppm/°C).This performance of temperature stability is approximately 4400% higher than the traditional picowatts-level reference circuit based on standard CMOS technology in the field.After that,based on the presented picowatts-level voltage reference circuit model,two different circuit structures(the pre-regulator circuit structure and the self-regulating circuit structure)are proposed to design two high-performance(ultra-high performance of line regulation and PSRR)reference circuits,respectively.With VIS 0.18 ?m technology,the specific implementation of this two circuits are introduced.The simulation results show that the two circuits both achieve high overall performance.They not only can be fully compatible with standard CMOS technology,but also achieve excellent performance of line regulation and PSRR,while achieving picowatts-level power consumption.Among them,the self-regulating voltage reference circuit only consumes 118.4 pW at a supply voltage of 1 V.The average temperature coefficient of the voltage reference is 83.2 ppm/°C.The circuit achieves a line regulation of 0.4 ppm/V and a PSRR of-76 dB at a 100 Hz.Compared with the traditional picowatts-level voltage reference circuit,the self-regulating picowatts-level reference circuit's performance of line regulation is improved by at least 825 times,and the PSRR is improved by about 400%.