Current limit protection circuit for a voltage regulator
US6466422B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 31, 2001 |
| Grant date | Oct 15, 2002 |
| Priority date | — |
| Expiry date | Dec 31, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F1/565
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A voltage regulator includes a power transistor receiving a drive current, and a current limit protection circuit connected to the power transistor. The current limit protection circuit includes a first resistance connected to the power transistor for sensing an output current, a limit switch transistor connected to the power transistor and to the first resistance, and a current generator and second resistance connected thereto. The current generator and second resistance biases the limit switch transistor to divert drive current from the power transistor based upon the output current through the first resistance exceeding a threshold. The first resistance has a value less than a value of the second resistance. The first resistance can be made considerably smaller than otherwise to thereby reduce power consumption. The temperature coefficient for the second resistance is balanced with respect to a temperature coefficient for the first resistance so that a output current from the voltage regulator is not sensitive to temperature variations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.