Design of Low Dropout (ldo) Voltage Regulator Using Bulk Modulation Technique

This paper describes the Designing of Low Power LOW DROP-OUT (LDO) Voltage Regulator using Bulk Modulation technique. Low-Drop-Out (LDO) voltage regulators are commonly used in electronic systems particularly in portable or low-power applications. Their main function is to provide a stable supply voltage by minimizing the ripples and noises caused by imperfect power sources and/or variable load currents. In portable devices and many biomedical implants, the power consumption of the regulator as well as its recovery time are among the important design considerations. A proof-of-concept prototype is designed and in 0.13-um CMOS, to illustrate the enhancement that can be achieved by applying this technique. The proposed enhanced LDO regulator which is based on conventional LDO regulators is able to delivers up to 5 mA of load current while providing a 1 V ( 1.5% load regulation) drawing 99.0 from a 1.2 V supply. The proposed technique takes advantage of body effect to reduce the threshold voltage of the pass transistor for any given current load. The proposed structure improves line and load regulations as well as the driving capability of the regulator while it reduces the power consumption of the LDO as compared to conventional LDOs with similar performance. Compared to conventional LDO voltage regulators, the proposed circuit achieves improved accuracy, stability, and output load current capability. Measurement results confirm that as compared to conventional LDOs, the proposed circuit offers better stability as well as improvement in the load current delivery and faster recovery time for no-load to and from full-load transitions.