Overcurrent sensing circuit and self adjusting blanking
US6108182A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 30, 1998 |
| Grant date | Aug 22, 2000 |
| Priority date | — |
| Expiry date | Oct 30, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/0822
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A sensing circuit 100 includes two resistors 11 and 12, two pnp transistors 13 and 14, and a current mirror 15 and 16. Resistors 11 and 12 convert the high voltages present in the bridge into a proportional current. The current mirror, mosfets 15 and 16, compares I.sub.1 and I.sub.2. If I.sub.2 is greater than I.sub.1 the voltage at point A is high. Otherwise this voltage is low. Resistor 12 is chosen smaller than 11 so that under normal operation, when FET 22 turns on, I.sub.2 is greater than I.sub.1 and the voltage at point A is high. During an overcurrent event, the drop across the FET 22, Von, is so great that I.sub.2 is less than I.sub.1 and the voltage a point A stays low.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.