Research And Design Of CMOS Bandgap Reference Based On High-order Curvature Compensation

Today's society is a rapid development of integrated circuit industry and semiconductor manufacturing technology,for the bandgap reference,which is one of the key modules of integrated circuits,people have found that the technical indicators of the traditional bandgap reference are far from to satisfy the demands of modern electronics.Modern circuit systems are pursuing a lower temperature coefficients,higher power supply rejection ratios,and high-precision output voltages.This is undoubtedly that poses a greater challenge to design a high-precision low-temperature drift bandgap reference.In this thesis,a bandgap reference voltage source with a high power supply rejection ratio,low temperature coefficient and high-precision is designed.According to the practical application.The thesis first analyzes the basic principles and basic types of the traditional bandgap reference sources,and focuses on the relevant index parameters of the bandgap reference circuit.At the same time,it conducts in-depth research on the various sub-module circuits that make up the bandgap reference circuit,and finally the bandgap reference circuit structure diagram required by various indicators.In the process of designing the bandgap structure in this thesis,the following innovative works are mainly carried out:In order to get the lower temperature coefficient,this article introduces a compensation circuit of high-order curvature compensation for temperature separately.The compensation circuit mainly utilizes the nonlinear relationship between the drain saturation current I_DS and the gate-source voltage V_GS of the MOS tube to output the compensation current I_comp which has a high-order curvature relationship with temperature in the compensation circuit,and the compensation nonlinear term in the base-emitter voltage V_BE for the high-order temperature,and finally obtains a lower temperature coefficient.In order to achieve a higher power supply rejection ratio,an ideal operational amplifier is used.This amplifier has an open-loop gain greater than 100d B and a smaller offset voltage,which can be used for voltage clamping in the bandgap reference circuit.At the same time,the amplifier itself has a relatively high power supply rejection,which can suppress the noise introduced in the power supply voltage very well.In order to obtain a higher precision reference voltage,a resistance trimming networks is proposed.This design is not only able to artificially adjust the accuracy and the amplitude of the bandgap reference voltage through the switch of the control word,but also adjust the resistance network at the various process angles for a low temperature drift bandgap reference voltage,which makes the design more reliable.The design is carried out under the CMOS process of TSMC 180nm,the experimental results shows that in a wide temperature range of minus 25 to 125 degrees,the power supply voltage is 3.3V,and the process parameters under the conditions of tt?3V,tt?res,the pre-simulation temperature coefficient is about 0.6ppm/?,the post-simulation result is about 0.7ppm/?,and the temperature drift result of the chip tapeout test is 0.82ppm/?.The power supply rejection ratio is 51d B in the low frequency band,and the power consumption is about 1.3m W.the layout area is 1.2mm*0.5mm.