Insulated gate bipolar transistor with current detection function
US5448092A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 1, 1993 |
| Grant date | Sep 5, 1995 |
| Priority date | — |
| Expiry date | Jun 1, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D89/60
Abstract
An insulated gate bipolar transistor (IGBT) element has a current detection function. An impurity-diffused area is formed at an area different from a unit cell area on the surface of the element. The current detection is performed by detecting a voltage drop due to carriers flowing in the lateral resistance of the impurity-diffused area. For example, in an n-channel IGBT, electrons are injected from a source electrode through an n-type source layer and the channel to an n-type drain layer at the cell when the unit cell is in an on-state. The pn junction at the drain side is forwardly biased to inject holes from the p-type drain layer to the n-type drain layer. At this time, the electrons also flow to the lower side of the p-type impurity-diffused area provided as the detection portion. Thus, the hole injection occurs at this portion. These surplus holes are discharged through the p-type layer of the detection portion to the source electrode. A potential which corresponds to a product of the lateral resistance of the p-type layer and a hole current appears at the source potential. By detecting this potential and converting the detected potential, an element current can be detected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.