Compensation Strategy And Circuit Design Of Low-Voltage Low-Power CMOS Reference

Reference sources including the reference voltage source and reference current source, are the basic units and important modules of analog circuits. As the integrated circuit feature size getting smaller in recent years, the power supply voltage and power consumption is getting lower and lower and meanwhile the accuracy of reference sources is getting more critical in today's applications. The study of the compensation strategy and circuit design of low-voltage low-power CMOS reference source is very meaningful as temperature compensation is the most crucial element to ensure accuracy and precision.The source of the nonlinear characteristics of reference sources is discussed, and several common high-order temperature compensation methods are introduced. On this basis, this paper designed a low-voltage, low-power CMOS bandgap reference voltage source. The circuit is first implemented with first-order temperature compensation, and compensated by two different high order compensation strategy later. As a result of current-mode architecture, the output voltage does not have a limitation of 1.25V. This project has an output voltage of 600mV, and may continue to be lowered as needed. A simulation is completed based on SMIC 0.18um CMOS technology; the simulation results show that the circuit has very good temperature characteristics, high power supply rejection ratio and good voltage regulation. The low-frequency PSRR is 75dB. The temperature coefficient with first-order compensation, different resistance coefficient compensation and VBE linearization compensation is 13ppm/℃, 1.1ppm/℃, 1.6ppm/℃respectively.