An Output Capacitor-less LDO with a Fast Transient Response using Two Positive Feedback Loops

Abstract

This paper proposes an output capacitor-less low-dropout regulator (LDO) with a fast-transient response. The proposed LDO can have fast transient response by using positive feedback loops which are implemented by the simple change from a conventional structure. In addition, the proposed LDO designs negative feedback loops with RC high pass filters which rapidly reflect output voltage variation to achieve the fast-transient response. The total compensation capacitance is 7.8 pF. The maximum load current supplied by the LDO is 100 mA and it consumes static current of 9 μA. The proposed LDO has been implemented in 0.18 μm CMOS technology and the active chip area is 0.0146 mm2.