Reverse battery protection circuit

• US 20040145353A1
• Filed: 12/02/2003
• Published: 07/29/2004
• Est. Priority Date: 12/05/2002
• Status: Active Grant

• Current Assignee: Infineon Technologies Americas Corp. (Infineon Technologies AG)
• Original Assignee: International Rectifier Corporation (Infineon Technologies AG)
• Inventors: Dubhashi, Ajit
• Granted Patent: US 6,969,971 B2
• Time in Patent Office: Days
• US Class Current: 320/165
• CPC Class Codes: H02H 11/003 using a field effect transistor as protecting element in one of the supply lines
• CPC Class Codes: H02J 7/0034 using reverse polarity correcting or protecting circuits mechanical means of polarity protection H02J7/0045

Abstract

A reverse battery protection circuit comprising a first controlled semiconductor switch for providing current to a load and coupled in series with load terminals across which load terminals the load is adapted to be connected and a second controlled semiconductor switch disposed in a series circuit with a free wheeling diode, the series circuit being coupled across the load terminals.

Claims

1. A reverse battery protection circuit comprising:

a first controlled semiconductor switch for providing current to a load and coupled in series with load terminals across which load terminals the load is adapted to be connected; and

a second controlled semiconductor switch disposed in a series circuit with a free wheeling diode, the series circuit being coupled across the load terminals.

2. The circuit of claim 1, wherein the second controlled semiconductor switch has a control electrode coupled to a main current carrying electrode of the main switch.

3. The circuit of claim 1, wherein the semiconductor switches comprise FETs.

4. The circuit of claim 3, wherein the control electrode of the second controlled semiconductor switch is coupled to the drain of the first controlled semiconductor switch.

5. The circuit of claim 4, further comprising a zener diode coupled between gate and source of the second controlled semiconductor switch.

6. The circuit of claim 1, further comprising a driver circuit for the first controlled semiconductor switch.