Circuits and methods for increasing switch turn-off speed in high-speed switching regulator drive circuits
US5668493A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 7, 1995 |
| Grant date | Sep 16, 1997 |
| Priority date | — |
| Expiry date | Jun 7, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K2217/0036
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Circuits and methods are provided for increasing the turn-off switching speed of a high-speed integrated circuit, bipolar switching regulator. The regulator The circuit runs at megahertz frequencies, yet is efficient as previously available bipolar integrated circuit switching regulators operating at much lower frequencies. The increased speed switch turn-off circuitry prevents the switch from spending too much time in a high power state (which would slow the switch down), increases the stability of the switch as compared with previously known designs. In a preferred embodiment, the circuitry includes a PNP transistor and a diode-connected transistor with their base-emitter circuits coupled to form a loop with the base-emitter circuit of a NPN transistor and the base-collector circuit of the switch to limit the on state voltage of the switch and control its depth of saturation. A capacitor is connected across the diode-connected transistor to reduce instabilities due to ringing caused by delays in the feedback loop.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.