Design Of A Voltage And Current Reference Source Based On 65nm CMOS Process

The voltage and current reference source module has lots of distinguishing feature such as do not change with temperature and process corner,even high PSR,and widely used in lots of module which require voltage and current to be stability such as ADC(Analog-to-Digital Converter)?DAC(Digital-to-Analog Converter)?LNA(Low Noise Amplifier)?VCO(Voltage Controlled Oscillator).65-nanometer line-width technology has a lot characteristics such as high level of integration? low cost?low calorific value per unit area?low power consumption per unit area.CMOS technology is the modern mainstream integrated circuit manufacturing technology,and existing BI-CMOS is fully compatible with bipolar process,and compatible with digital and analog CMOS process,can reduce the design difficulty and manufacturing cost.This paper based on the 65 nm CMOS process,through the study of the basic CMOS voltage and current reference source,optimized and improved on basic CMOS reference source from the mainstream view of today's technology.This paper introduces a design of a voltage and current source reference module which provides reference for radar SOC system module,this reference module include three sub-modules,respectively named band-gap module?low dropout linear voltage regulator module and bias current module.Module's sub circuits are designed in transistor level based on principle of each module under 65 nm COMS process.Hereinto,band-gap reference using two order curvature compensation?TRIM resistance array technology,make the temperature coefficient has been optimized greatly.Error amplifier adopted folded cascade structure and self-bias two level link structure,which makes the amplifier gain and power supply rejection greatly improved.Low dropout linear voltage regulator module uses the basic structure,the noise optimization using low pass mechanism,further optimization of the noise from the layout design,so that the medium frequency active noise reduced greatly.Bias current module use trim resistance array technology,so that the temperature coefficient greatly optimized,using the class LDO structure provides a 10 uA constant current for other modules.Through Cadence simulation software to the corner for the preliminary simulation,and finish the corner's later simulation by Ocean script.The simulation results show that op-amp's gain of Band gap reference in the worst condition is 58 dB,in the optimized condition it reach to 95 dB.Output voltage of band-gap voltage is 1.2V,the temperature coefficient of the worst condition is 21.37ppm/?,the temperature coefficient of the optimized condition is 17.86ppm/?.Op amp's PSR in all corners are all overtop 70 dB.The op-amp's best loop gain is 96 dB,the worst loop gain is 60 dB,meanwhile ensure the various conditions of gain margin is more than 20,the phase margin is greater than 45.The offset current temperature coefficients guarantee around 35ppm/?.Low dropout linear voltage regulator's noise at 100 k in any corners are all under 11.3 nV/sqrt(Hz),meanwhile noise at 1M in any corners are all under 8.865 nV/sqrt(Hz).Op-amp's gain of low dropout linear voltage reference at the worst condition is 71 dB,at the best optimized condition is 102 dB.And the PSR of low dropout linear voltage reference module are all overtop 60 dB in any corners.The above results are obtained to meet the requirements of modern mainstream technology for voltage and current reference source.