Design Of Low-Temperature Drift CMOS Bandgap Voltage Referenc

The bandgap reference is a critical part of analog,digital,and mixed-signal circuits,and for many circuit blocks,a stable reference voltage is required.As technology continues to advance,higher performance requirements are placed on bandgap benchmarks.In this paper,two voltage references are proposed,namely a full CMOS reference and a low-drift bandgap reference.In the first reference structure,a bias circuit is used to generate a current proportional to the absolute temperature and introduce this current into the NMOS tube to obtain a reference voltage.Because the structure of the all-CMOS reference source is unsatisfactory in terms of temperature coefficient and power supply rejection ratio,a low-temperature drifting bandgap reference source is proposed.In the second reference source structure,in order to reduce the temperature coefficient,the PTAT current and CTAT current are first added to achieve the first-order temperature compensation,and then the I_PTAT² current is used to achieve the second-order temperature compensation.In order to improve the power supply rejection ratio,the core circuit adopts the Cascode structure,and a negative feedback pre-regulator circuit block is designed as a buffer stage.To reduce linearity errors caused by production process mismatches,resistor trimming networks are used.This time,the simulation platform Cadence Spectre simulated the two circuits based on the TSMC 0.13μm process.The simulation results show that in the temperature range of-40℃～125℃,under the optimal case,that is,the TT process angle,the output voltage of the first reference source is 578.0mV,the temperature coefficient is 20.97 ppm/℃,the power supply voltage rejection ratio is-47.03dB at 100KHz,the linear regulation rate is 1.7%/V,and the power consumption is 2.45μA;the output reference voltage of the second reference source is 470.66mV,and the temperature coefficient is 2.51ppm/℃ in the optimal case.After adjustment,the temperature coefficient under the full process angle can be less than 6ppm/℃,the quiescent current power consumption is only 41.39μA,the linear regulation rate is 0.028%/V,and the low-frequency power supply rejection ratio can be as high as-97.02dB.This structure improves some parameters of the first reference circuit structure,although the power consumption is slightly increased,the temperature coefficient is reduced by a factor of7,the rejection ratio of the low-frequency power supply is improved by 50dB,and the linearity regulation is reduced by a factor of 60,and the overall performance is greatly improved.