Short-circuit current-limit circuit
US6285177A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 8, 2000 |
| Grant date | Sep 4, 2001 |
| Priority date | — |
| Expiry date | May 8, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F3/262
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A current-limit circuit and a method of limiting current supplied to a load through a power transistor utilize a control transistor that is selectively activated to a conducting state to limit the current conducted through the power transistor in response to a predefined condition. The predefined condition may be a short-circuit condition or an over-current condition. The configuration and operation of the control transistor are such that, when the control transistor is in a conducting state, the current conducted through the power transistor is limited by the structural ratio of the two transistors. However, during normal operating conditions when the control transistor is deactivated to a non-conducting state, the control transistor does not degrade the performance of the power transistor. In a first embodiment, the current-limit circuit is configured to provide protection from a short-circuit condition. In a second embodiment, the current-limit circuit is configured to provide protection from an over-current condition, in addition to protection from a short-circuit condition. In a preferred embodiment, the sense transistor and the power transistor are structurally integrated int…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.