Design And Radiation-hardening Of High-Performance Low Dropout Regulators

The stability of power circuit has a significant impact on circuit performance. With the rapid development of aerospace, aviation and nuclear applications, more and more electronic systems need to work in the radiation environment which facing the threat of radiation effect. When the power supply chip suffering from radiation environment,the output voltage of which will change and be long time deviation from standard level because of the effect of Single Event Transients (SETs). Along with the technology developing and the power supply voltage declining, the percentage of jumping voltage caused by SETs becomes higher, and the circuit stability problem caused by SET effect becomes more and more seriously. Therefore, the design of high performance power circuit working in radiation environment becomes an urgent task in IC engineering.The Low Dropout Regulators (LDO) is one of the most common power circuits. It is widely used for its stability. Through the analysis, the performance of typical LDO is restricted by structure loop parameters. In order to achieve high-performance, a new circuit structure is needed with radiation-hardened-by-design. To solve this issue, we design a new LDO.This paper mainly focus on:1,Based on the typical structure LDO and the control theory of the charge pump phase-locked loop, a new model of LDO circuit structure is designed, and the loop parameters are analyzed. These provide parameters for the design of new LDO circuit;2,According to the new LDO model, we designed the circuits of each module of LDO and analysed their SET responses;3,The LDO circuit can achieve the best performance by finely tuned based on designed circuits of each module, and compared with the same kind of circuits[37], over shoot decreases by 22%~50%. It's almost three times larger than the circuit[37] in the load current range. These proved that the design of this paper have high performance;4,According to the SET response results of each module and the LDO, we hardened the LDO in design, and compared with the one by the similar technique, the over shoot decreases by 14%~36%. Obviously, its performance is better than the plain one[37]. In addition, it's no doubt that radiation-hardened-LDO is less sensitive to SET. In the light load condition, to our surprise, the maximum range of output change reduce by 76.9%, what's more, the maximum of recovery time also drop sharply, about 78.3%; while in the heavy load condition, it's not so obvious for the maximum range of output change which fall by 38.1%; By the way, in such condition as change from heavy load to light one, the maximum range of output change and recovery time decrease by 58% and 65% respectively. This paper has testified that the LDO after being hardened turns out to be an excellent performance and less sensitive to SET by simulation and verification5,The layout of the radiation-hardened-LDO is implemented in 0.13μm CMOS process. It's proved that it has favourable performance by simulation.