Power regulator having over-current protection circuit and method of providing over-current protection thereof
US7362080B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 20, 2005 |
| Grant date | Apr 22, 2008 |
| Priority date | — |
| Expiry date | Feb 21, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F1/573
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A power regulator includes a pass transistor, a feedback circuit, an error amplifier and a protection circuit. The pass transistor receives an unregulated first power supply voltage, and an output terminal of the power regulator outputs an output voltage varying depending upon a control signal. The feedback circuit senses a current flowing through the pass transistor and generates a feedback signal. The error amplifier compares a reference signal to the feedback signal and generates a control signal varying depending upon a voltage difference between the reference signal and the feedback signal. The protection circuit scales down a current flowing through the pass transistor by a prescribed ratio and changes a voltage of the control signal when the scaled-down current has a value higher than a prescribed value. Accordingly, the power regulator may control a current limit correctly and be capable of implementing a sensing resistor having an appropriate resistance value for providing over-current protection that occupies a smaller chip area.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.