Thermal shutdown trip point modification during current limit
US7301746B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 21, 2005 |
| Grant date | Nov 27, 2007 |
| Priority date | — |
| Expiry date | Jun 30, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K2017/0806
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A thermal shutdown circuit for protecting a main FET that conducts a load current ILOAD. A reference circuit provides a temperature current proportional to temperature. A thermal sensor circuit has a resistor and generates an output signal signaling thermal shutdown when the voltage generated across the resistor by the temperature current exceeds a predetermined value. A sense FET having a size smaller than the main FET conducts a sense current ISENSE proportionately smaller than ILOAD. A current mirror mirrors a scaled current proportional to ISENSE to be conducted through the resistor, the scaled current being scaled so as to cause the voltage generated across the resistor to exceed the predetermined value when ILOAD exceeds a predetermined value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.