A Fast-Transient Radiation-Tolerant LDO-cum-Latching Current Limiter

The low-dropout regulator (LDO) and the latching current limiter (LCL) are two important constituent components of the power management system in satellites, including for the impending 6G satellite communications. In this article, we present a fast-transient radiation-tolerant LDO-cum-LCL realized in CMOS (vis-à-vis III/V or BiCMOS exotic processes). The LCL therein detects load current anomalies, thereby protecting the load against current anomalies (when the load suffers from single-event-latch-up, a radiation effect). The fast-transient response is realized by our proposed triple-feedforward-path technique that is efficacious over wide range of load currents (up to 3A) and off-chip capacitors (100 to 880 μF). The LDO-cum-LCL is monolithically realized in a 130 nm CMOS process. The dropout voltage is 210 mV at the full load, and the overshoot and undershoot are 14.2 and 11.8 mV, respectively, at fast 3A load transitions. The load regulation is 0.15 mV/A while the power supply rejection is −52.3 dB@100 kHz. These parameters of the LDO-cum-LCL are very competitive when benchmarked against reported LDOs, albeit the reported LDOs not featuring radiation tolerance.