Circuit and method for preventing reverse current flow into a voltage regulator from an output thereof
US7859240B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 22, 2008 |
| Grant date | Dec 28, 2010 |
| Priority date | — |
| Expiry date | Jan 31, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F1/56
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A circuit and method are provided for interrupting current flow into a voltage regulator from an output thereof when a voltage source (Vpwr) drops below an output voltage (Vout). In one embodiment, the circuit comprises: (i) a comparator supplied by Vout including an output and inputs coupled to Vpwr and Vout; and (ii) transistors coupled to and controlled by the comparator, including a first transistor configured to interrupt a first current path extending between Vout and Vpwr through an output-leg of the regulator when Vpwr drops below Vout. Preferably, the regulator includes a reference-leg and a feedback-circuit coupling Vout thereto, and the first transistor also interrupts a second current path between Vout and Vpwr through the feedback-circuit and reference leg. More preferably, the reference-leg comprises resistors through which it is coupled to ground, and the transistors include a second transistor to interrupt a third current path between Vout and ground.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.