Research And Design Of High Performance Bandgap Voltage Reference

Voltage reference is a crucial unit in analog chip and digital-analog mixed chip.It provides accurate and stable power supply for other circuits of the chip to ensure good overall performance of the chip.Bandgap voltage reference is one of the most widely used types in voltage reference topologies.Therefore,high performance bandgap voltage reference is the focus of current research.At present,high performance bandgap voltage references are mainly reflected in three aspects:low temperature coefficient,high power supply rejection ratio and low power consumption.First,the output reference voltage of the bandgap voltage reference is required to have a smaller change with temperature in a certain temperature range compared to an external power supply.Second,bandgap voltage reference must have strong anti-interference ability to the noise of power supply voltage.Third,with the advent of the Internet of things era,the working life of the core carrier——wearable device has become the biggest technical challenge.In order to extend the service life of the device,bandgap voltage reference needs to meet the requirement of ultra-low power consumption.Different chips have different requirements for the performance index of bandgap voltage reference,so we should focus on optimizing one index while taking into account other indexes.Therefore,the study has great practical significance for bandgap voltage references in different applications.In this paper,two bandgap voltage reference circuits are designed for power consumption and temperature coefficient.Firstly,a voltage-mode voltage reference with ultra-low power consumption is proposed.The circuit generates a proportional-to-absolute-temperature voltage by cascade of four stages of self-cascaded structure operating in the subthreshold saturation region.And it is used to compensate the emitter junction voltage of the transistor to obtain the output reference voltage.Based on GSMC 180nm CMOS process,the circuit is designed and simulated using the Cadence Spectre simulation tool.The post-simulation results show that,the temperature coefficient is 18.5 ppm/? in the temperature range from-40? to 130?,the output reference voltage at 27? is 508.1 mV,the static operating current is only 699.6pA at 1.8V power supply voltage,the power supply rejection ratio at low frequency is-44.52dB,and the layout area is 60.96×32.68 ?m2.Secondly,based on the traditional Banba bandgap reference,a current-mode bandgap reference with low temperature coefficient is designed.The high-order curvature compensation structure in this circuit eliminates the high-order nonlinearity of the transistor's emitter junction voltage and reduces the temperature coefficient of the circuit.At the same time,in order to extend the operating temperature range of the circuit,the piecewise curvature compensation technique is used to further compensate the output reference voltage in the higher temperature range.Finally,under the TSMC 180nm CMOS process,a series of tasks including circuit design,layout design,circuit simulation,tape-out and testing are completed.The measured results show that the temperature coefficient is as low as 7.2 ppm/? in the range of-40? to 160?,the power supply rejection ratio at low frequency is-48.52dB,the total current under 1.8V power supply voltage is 68.38?A,and the effective area of the chip is 0.025mm2.