Conclusion
The proposed LDO has good performance in quiescent power, efficiency and load regulation. The almost infinite DC gain due to the integrator-based design provides sufficient loop gain even when the power transistor is in deep linear region. The current-steering charge pump with unit buffer results in better line regulation; a voltage mapping network results in the support of even lower dropout voltages which results in higher efficiency and an input voltage of as low as 0.8V can be achieved at much lower quiescent power.
Experimental results show that the VCO-integrator-based LDO performance exceeds the performance of traditional LDO on the same chip in key parameters such as power, efficiency and accuracy. It also exceeds the performance in several parameters compared to other LDOs in the sub-1V range.
The integrator-based approach for LDO is a promising way of implementing in low-power high-efficiency systems.