The Research And Design Of CMOS Bandgap Voltage Reference

The in-depth development of the information industry revolution has promoted the vigorous development of the semiconductor industry,and has also expanded and extended the use of integrated circuits.At the same time,the performance requirements for each module in the integrated circuit are getting higher and higher.The reference voltage as an integrated circuit module that can provide a stable and accurate reference voltage for other circuits or systems,its performance will directly affect the overall performance of the integrated circuit system.Bandgap reference has become the most widely used reference source for its good process compatibility and excellent performance.Therefore,this article focuses on the indepth study and design of the bandgap reference voltage source.In this paper,the working principle of the bandgap voltage reference is firstly discussed in detail.Several classical bandgap reference voltage sources are analyzed and compared.The error factors affecting the performance of the bandgap voltage reference are analyzed in depth and the bandgap is analyzed.Reference voltage high-order temperature compensation method.Then,based on the theoretical analysis of the bandgap reference voltage source,two bandgap reference voltage sources are designed for different application requirements.(1)For the shortcomings of the traditional first-order temperature compensation bandgap reference source,a bandgap reference voltage source with low temperature coefficient and high power supply rejection ratio is implemented in SMIC 0.18?m CMOS process.On the basis of conventional first-order temperature compensation,a dynamic threshold MOS tube is used to generate a temperature compensation current,the temperature profile of the reference source output is modified,and the temperature coefficient of the output voltage is reduced;a low-pass filter composed of MOS transistors is used to filter out high frequencies.Noise improves the power supply rejection ratio of the reference source.After theoretical analysis and simulation verification,the bandgap reference voltage source has a temperature coefficient of 1.54 ppm/°C in the temperature range of-40 °C to 130 °C.The power supply rejection ratio is-76 dB at the frequency of 10 Hz,and is at the frequency of 100 kHz.It is-85 dB and-63 dB at 15 MHz.(2)To meet the needs of low voltage applications,a low voltage bandgap voltage reference was designed in SMIC 0.18?m CMOS process.The negative feedback clamp circuit is used instead of the op amp in the traditional reference source to reduce the error caused by the op amp misadjustment.The use of segmented temperature compensation technology reduces the temperature coefficient of the output voltage,and the current mode technology is used to achieve the low voltage output.The simulation results show that the temperature coefficient is 11.2 ppm/°C and the power supply rejection ratio is-74 dB over the temperature range of-40 °C to 125 °C.Finally,according to the layout rules of the integrated circuit,the layout design of the bandgap reference voltage sources designed in this paper is carried out.In summary,the two bandgap reference voltage sources designed in this paper have good comprehensive performance and can provide high-accuracy reference voltages for data conversion circuits and power management chips,and have great application value.