Design Of High Precision And Wide Temperature Range Negative Voltage Detection Circuit

In recent years,the negative voltage detection circuit plays an important role in ensuring the normal operation of the negative voltage driving chip.Traditional negative voltage detection circuit need to introduce negative reference voltage,for itself without the negative voltage of the chip,the voltage can be introduced from the outside,however it is difficult to meet the requirements of chip,how to realize the negative voltage detection under the positive voltage supply without introducing the negative reference voltage is a hot topic in the academic field.Therefore,the study of negative voltage detection circuit has theoretical significance and practical value.In this thesis,a kind of negative voltage detection circuit with high precision and wide temperature range is designed,realizing negative.voltage detection under the positive voltage supply without introducing the negative reference voltage,and realizing high precision detection and wide working temperature range.Firstly,in this thesis,the realization method of the negative voltage detection circuit under the positive voltage supply is studied,and a sampling voltage generation circuit is designed,which is composed of a low voltage linear regulator LDO with a fixed 2.5V voltage and a resistor divider network,its role is to raise the negative voltage signal of the input to a positive sampling voltage.In the design,the error amplifier of low voltage linear regulator adopts folded cascode structure to improve the loop gain,and irproves the precision of LDO.Secondly,in order to meet the requirements of high precision and wide temperature range,based on this method,depth analysis the intrinsic mechanism of the precision and working temperature range of negative voltage detection circuit,a bandgap voltage reference circuit is designed,which is insensitive to temperature and the power supply voltage,and even the impact of process conditions,and a high precision voltage comparator is designed.This comparator with two pre amplifier and a latch level circuit structure,and in the pre amplifier common mode feedback circuit is introduced to improve the gain,and improve the accuracy of comparator,at the same time,the negative side load of latch using PMOS as a negative resistance in parallel with the diode connected PMOS,the tradeoff between accuracy and speed for gain and bandwidth is considered,make the comparator has high detection accuracy and fast comparison,the comparison results after a push-pull output stage and after two level output buffer,converts the analog signal to digital signal.Finally,a output driver is designed,which is based on signal path diversity technology and distributed weighted driving technology.In this thesis,the design of high precision,wide temperature range of negative voltage detection circuit,based on the Chart 0.35?m standard CMOS technology,the circuit and layout design has completed.The post-simulation results show that the high precision and wide temperature range of negative voltage detection circuit in the working temperature range of-55?125?,the highest detection accuracy can reach up to 0.2mV,the transmission delay was below 25ns.All the results meet the circuit design requirements.