Slew-rate control apparatus and methods for a power transistor to reduce voltage transients during inductive flyback
US7365584B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 2, 2006 |
| Grant date | Apr 29, 2008 |
| Priority date | — |
| Expiry date | Jul 11, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/163
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Apparatus and methods that reduce the amount of conducted/radiated emissions from a power switch (200) when a transistor (210) is switched OFF are disclosed. In addition, apparatus and methods that reduce the slew rate in a power switch when the power switch is switched off are disclosed. The apparatus comprises a transistor (210) including an inductive load (230) coupled to the transistor, a plurality of current sources (222, 224) coupled to the gate of the transistor, and a clamp (250) coupled to either the gate and the drain of the transistor, or to the gate and to ground depending on the location of the inductive load, wherein the clamp comprises a resistive element (260) to increase the voltage of the clamp when current flows through the clamp, and wherein the increased voltage causes the apparatus to include a different slew rate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.