Over-current protection circuit and method
US6807040B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 19, 2001 |
| Grant date | Oct 19, 2004 |
| Priority date | — |
| Expiry date | Jul 27, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F1/523
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Over-current protection is accomplished in an output transistor (MP) of an electronic circuit wherein an input signal (Vgatedrive) Is Applying to a first conductor (19) coupled to a gate of the output transistor to cause an output current (Iout) to flow through the output transistor and an output terminal (11) of the electronic circuit. A limit voltage (VLIMIT) who is applied to an input (21) of a voltage clamping circuit (18) to cause a clamping current to flow in the first conductor (19) as needed to prevent the magnitude of the input signal (Vgatedrive) from being less than the magnitude of the limit voltage (VLIMIT) so that the output current (Iout) is limited to a maximum current limit determined by the limit voltage (VLIMIT). A control signal (ILIMIT/n) is applied to an input of a current-to-voltage conversion circuit (20) to cause the current-to-voltage conversion circuit to produce the limit voltage (VLIMIT), which is applied to an emitter of a first transistor (Q1) having a collector in base connected to a bias current source (I1). The resulting voltage on a base of the first transistor is applied to a base of a second transistor (Q2), and the input signal (Vgatedrive) is …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.