Adaptively-biased capacitor-less CMOS low dropout regulator with direct current feedback

A capacitor-less low dropout regulator (LDR) with direct current feedback is proposed. A symmetrically-matched voltage mirror in sensing the load current is employed, and gives excellent line and load regulations. The dynamic biasing results in an LDR with pole-tracking that extends the bandwidth of the loop gain at high load currents. The LDR was fabricated in a 0.35mum CMOS process with an active area of 0.11mm², and measurement results corroborated well with both analysis and simulation