Fast-Transient Radiation-Hardened Low-Dropout Voltage Regulator for Space Applications

Abstract

This article presents a fast-transient radiation-hardened low-dropout (LDO) voltage regulator integrated in a standard 0.6-<inline-formula> <tex-math notation= LaTeX >$\\mu \\text {m}$ </tex-math></inline-formula> BiCMOS technology for space and other harsh radiation environment applications. The fabricated LDO consumes 150-<inline-formula> <tex-math notation= LaTeX >$\\mu \\text {A}$ </tex-math></inline-formula> quiescent current at 6-A maximum output current. An LDO voltage of 300 mV which corresponds to an ultralow <inline-formula> <tex-math notation= LaTeX >$R_{\\text {DS}(\\text {ON})}$ </tex-math></inline-formula> resistance of 50 <inline-formula> <tex-math notation= LaTeX >$\\text{m}\\Omega $ </tex-math></inline-formula> is realized by accurate modeling. A separate fast-transient response circuit under narrow-bandwidth condition is proposed to improve the output voltage transient speed. It operates from an input voltage range of 2.8–5.5 V and provides an output voltage of 2.5 V, with output voltage accuracy of ±2%. The proposed LDO achieves a successful line regulation of 1 mV/V, and a load regulation of 2.16 mV/A. Effective radiation-hardened layout techniques are applied to realize high area-efficient LDO chip, whose total area including pads is 5.35 mm², which represents only about one-third area of similar radiation-hardened products. Furthermore, a special set of total ionizing dose (TID) experiments and single-event latch-up (SEL) experiments were performed. The measurement results show that the LDO can tolerate up to a TID of 150 krad (Si) and SEL immunity at a linear energy transfer (LET) of 99.8 MeV/(mg/cm²) with proposed layout design.