Integrated power management system based on efficient LDO-assisted DC/DC buck converter

In this paper, a new structure based on linear-assisted DC-DC buck converter principle is proposed. Using a new class-AB LDO regulator instead of the conventional linear one (based on a push-pull output stage) in the hybrid scheme, reduces the difference between input and output voltages and also the switching frequency of the buck converter. Thus, the proposal achieves higher power efficiency rather than the conventional linear-assisted converter, desired for power management systems of battery operated devices like biomedical implants and energy harvesting applications. In addition, the circuit provides a lower output ripple and better transient response. A comparison analysis is done with regards to the considered performance indexes between the proposed structure and linear-assisted buck converter, and the results are validated in HSPICE in a 0.35 μm CMOS process.