Bridge circuit having polarity inversion protection means entailing a reduced voltage drop
USRE36472E · kind E · reissue
Assignee
Inventors
Key dates
| Filing date | Mar 16, 1995 |
| Grant date | Dec 28, 1999 |
| Priority date | — |
| Expiry date | Mar 16, 2015 |
Classification
- Technology area (CPC —)General
Abstract
The additional voltage drop across a guard diode against supply polarity inversion in an integrated bridge circuit for driving an external load and employing two high-side NPN power switches driven by two PNP transistors, all monolithically integrated using a junction-type isolation technique, is substantially eliminated by connecting the emitters of the two PNP drive transistors directly to the positive rail, i.e. to the anode of the guard diode. Integrated PNP transistors are per se intrinsically protected against polarity inversion and when so connected permit to reduce the overall voltage drop across the driving bridge circuit. Using a Zener diode as the guard diode and a second Zener diode connected in opposition to the first Zener between the cathode thereof and the negative supply rail an additional spike protection of the circuit's components is implemented.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.