A fast-transient low-dropout regulator with current-feedback-buffer (CFB) for SoC application

The design of a low-voltage fast-transient low-dropout regulator (LDR) with a current feedback buffer (CFB) for system-on-ship (SoC) applications is presented. When the CFB senses variation in the load current, it quickly controls the power transistor to achieve fast-transient and small output voltage variation. The proposed LDR has high current efficiency because the CFB can adjust the quiescent current at various load currents. A 1 V capacitor-less LDR with a 1.2 V power supply was fabricated in 0.35 µm CMOS technology. The CFB improves the current efficiency from 66.5% to 99% in light load.