An efficient CMOS LDO-assisted DC/DC buck regulator

In this paper, a new structure based on linear-assisted DC-DC buck converter principle is proposed. Using a segmented LDO regulator instead of the conventional linear one in the hybrid scheme, reduces the difference between input and output voltages and also the switching frequency of the buck converter, while the circuit provides a lower output ripple, better transient response. In addition, the proposal achieves higher power efficiency rather than the linear-assisted converter, desired for power management systems of battery operated devices like biomedical implants and energy harvesting applications. A comparison analysis is done with regards to the mentioned 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.