Research And Design Of Radiation Hardened Low Dropout Linear Regulator

Low-Dropout regulators(LDOs)have these performances of low power consumption,low noise and simple structure,and which have been widely used in the aerospace field.Therefore,it is needed that the LDO can provide a stable power supply in an irradiation environment.When high-energy particles bombard sensitive nodes of LDO in radiation environment,the output voltage of the LDO will suddenly deviate from the stable voltage and will cause abnormal operation of the circuit system.Therefore,this thesis will design a radiation-hardened LDO in SMIC 0.18?m CMOS process.The main research contents of this paper include three points as follows.First,based on analysis of the Bandgap Reference(BGR)basic principles,a low-power bandgap reference circuit is designed by using MOS diode technology.Simulation results show that the temperature coefficient of the designed bandgap reference circuit is 9ppm/?and the power supply rejection ratio is-96dB@1KHz.Secondly,on the basis of analysing the frequency compensation structure of the classical three-stage amplifier,a three-stage amplifier is designed by using the Damping Factor Control Frequency Compensation(DFCFC)and Q-reduction.Simulation results show that the DFCFC&Q-reduction three-stage amplifier achieves DC gain of 99dB,phase margin of60.47~?and gain bandwith produce of 6.5MHz.Finally,Over Current Protection(OCP)and Over Temperature Protection(OTP)circuits are designed for LDO by using SMIC 0.18?m CMOS process in thesis.At the same time,based on the designed DFCFC&Q-reduction three-stage amplifier,a radiation-hardened LDO was designed by using Temporal-filtering technology.Radiation-hardened LDO achieves linear regulation of 0.0194%,load regulation of 0.36%and maximum load current of 100mA.The LDO achieves the PSRR of-100dB,-57.56dB and-22.40dB at 1Hz,1KHz and 100KHz respectively.Under the condition of the protection circuit,the maximum short-circuit protection current output is 124.12mA,and the temperature hysteresis is a 30?.When a double-exponential transient current pulse with a peak value of 1 mA is introduced into the radiation-hardened LDO sensitive node,the LDO output voltage change is less than 3%and it can resist the single event effect of LET?50MeV?cm~2/mg.