Low voltage dropout regulator
US4792747A · kind A · utility
43Cited by
2References
14Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 1, 1987 |
| Grant date | Dec 20, 1988 |
| Priority date | — |
| Expiry date | Jul 1, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F1/56
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A high efficiency dropout regulator (60) drives an output transistor (22) with a PNP transistor (52) if the overhead voltage from input (14) to output (26) is below a predetermined voltage. If the overhead voltage exceeds the predetermined voltage, then a second PNP transistor (64) and an NPN transistor (72) are used to drive the output transistor (22), resulting in a large reduction of power loss. The current drawn from the output transistor (22) by the NPN transistor (72) is returned to the output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.