Analysis and design of fully integrated very low quiescent current LDOs

摘要

We introduce two extremely low quiescent current (IQ) low-dropout (LDO) voltage regulators. The Low IQ-LDO (LIQ-LDO) has a minimum ground current of 13 µA and is designed for a maximum load current of 50 mA. The Micro IQ-LDO (MIQ-LDO) has a minimum ground current of 1.2 µA and is designed for a maximum load current of 5 mA. Detailed pole/zero analysis is performed to aid in the design of the LDOs. Two LHP zeros cancel the two non-dominant poles which extend the bandwidth and improve transient response. Both designs are fully integrated, stabilized with an on-chip capacitive load of 100 pF. A process-independent figure of merit (FOM) is proposed to compare LIQ-LDO and MIQ-LDO with other published work.