Simple power MOSFET low side driver switch-off circuit with limited di/dt and fast response
US5525925A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 22, 1994 |
| Grant date | Jun 11, 1996 |
| Priority date | — |
| Expiry date | Feb 22, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/163
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An output circuit includes a power MOSFET with a gate connected to a plurality of diodes, the plurality of diodes forming a diode string. A resistor is connected in parallel with the diode string. A switch is connected between the opposite end of the diode string and circuit ground. A control terminal of the switch is connected to the circuit input and determines whether the circuit is turned on or turned off. An inductive load is connected to a drain terminal of the power MOSFET. The opposite end of the inductive load is connected to a power supply. A source terminal of the power MOSFET is connected to circuit ground thus providing a low-side driver circuit configuration. The resistor and diode string, connected in parallel, along with the switch provide a two-phase, soft turn-off mechanism which allows the power MOSFET to dissipate the energy stored in the inductive load without the power MOSFET entering breakdown, therefore improving the circuit's reliability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.