LDO and load switch supporting a wide range of load capacitance

US8917070B2 · kind B2 · utility

Assignee

• Vidatronic, Inc. · US

Inventors

• Mohamed Ahmed Mohamed El-Nozahi · Cairo, EG
• Mohamed Aboudina · San Diego, US
• Sameh Assem Ibrahim · Cairo, EG
• Faisal Hussien · San Diego, US
• Moises E. Robinson · Austin, US

Key dates

• Filing date: Mar 14, 2013
• Grant date: Dec 23, 2014
• Expiry date: Mar 14, 2033

Classification

• Technology area (CPC G): Physics
• CPC primary: G05F1/565
• WIPO field: Control
• WIPO sector: Instruments

Abstract

A method to maintain stability of a low drop-out (LDO)/load switch linear voltage regulator (LVR). The method includes determining, during a power-up phase and by a capacitance sensing circuit, an estimated output capacitance value at an output node of the LDO/load switch LVR, and adjusting, based on the estimated output capacitance value, an adaptive RC network in the LDO/load switch LVR, wherein the adaptive RC network produces an adaptive zero in a feedback network transfer function of the LDO/load switch LVR, wherein the adaptive zero reduces an effect of a non-dominant pole in the open loop transfer function of the LDO/load switch LVR, and wherein a frequency of the adaptive zero is inversely proportional to the estimated output capacitance value.