Unlockable switch inhibitor

1. An apparatus comprising:

one or more metal-oxide-semiconductor field effect transistors connected in series between a supply voltage and an output terminal;

a charge pump configured to generate a voltage of sufficient magnitude relative to the supply voltage to switch the one or more metal-oxide-semiconductor field effect transistors into a conductive state; and

a driver circuit coupled between the charge pump and the one or more metal-oxide-semiconductor field effect transistors, wherein

the driver circuit (i) comprises at least one bipolar junction transistor having a collector terminal connected to a gate terminal of the one or more metal-oxide-semiconductor field effect transistors and an emitter terminal connected via a diode to either said supply voltage or a ground potential, and (ii) is configured to drive the one or more metal-oxide-semiconductor field effect transistors to provide at least one of power switching, reverse polarity protection, power switching with reverse polarity protection, or over voltage inhibition.

2. The apparatus according to claim 1 , wherein:

the one or more metal-oxide-semiconductor field effect transistors comprise N channel transistors; and

the charge pump is configured to generate a voltage more positive than the supply voltage.

3. The apparatus according to claim 1 , wherein:

the one or more metal-oxide-semiconductor field effect transistors comprise P channel transistors; and

the charge pump is configured to generate a voltage more negative than a ground potential.

4. The apparatus according to claim 1 , wherein:

the one or more metal-oxide-semiconductor field effect transistors comprise enhancement mode transistors.

5. The apparatus according to claim 1 , wherein:

the one or more metal-oxide-semiconductor field effect transistors comprise depletion mode transistors.

6. The apparatus according to claim 1 , wherein the apparatus drives a load connected between the output terminal and the ground potential.

7. The apparatus according to claim 6 , wherein the load comprises at least one of a heated steering wheel, a heated seat, a window defroster, a mirror defroster, a vibration generating device providing tactile feedback, a vibration generating device providing a driver warning, or other high current automotive accessory.

8. The apparatus according to claim 1 , wherein the driver circuit is further configured to control the one or more metal-oxide-semiconductor field effect transistors in response to a control signal.

9. The apparatus according to claim 1 , further comprising an over voltage inhibition circuit coupled to said driver circuit.

10. The apparatus according to claim 9 , wherein said over voltage inhibition circuit comprises a Zener diode and a resistor.

11. The apparatus according to claim 10 , wherein said over voltage inhibition circuit further comprises a second resistor and a bipolar junction transistor.

12. The apparatus according to claim 9 , wherein said over voltage inhibition circuit is configured to determine whether over voltage inhibition has priority.

13. The apparatus according to claim 1 , wherein:

said at least one bipolar junction transistor is configured to couple the gate terminal of the one or more metal-oxide-semiconductor field effect transistors to the supply voltage in a reverse polarity condition.

14. The apparatus according to claim 1 , wherein:

said at least one bipolar junction transistor is configured to couple the gate terminal of the one or more metal-oxide-semiconductor field effect transistors to the ground potential in response to a first state of a control signal and allow the gate terminal of the one or more metal-oxide-semiconductor field effect transistors to be biased by the charge pump in response to a second state of the control signal.

15. The apparatus according to claim 1 , wherein the driver circuit comprises:

a first bipolar junction transistor;

a second bipolar junction transistor;

a first diode;

a second diode;

a first resistor;

a second resistor; and

a third resistor, wherein

the supply voltage is presented to a first terminal of the first resistor and a cathode terminal of the first diode,

a second terminal of the first resistor and a first terminal of the second resistor are connected to form a node at which a control signal can be presented,

a second terminal of the second resistor is connected to a base terminal of the first bipolar junction transistor,

an emitter terminal of the first bipolar junction transistor is connected to an anode terminal of the second diode and a cathode terminal of the second diode is connected to the ground potential,

an emitter terminal of the second bipolar junction transistor is connected to an anode terminal of the first diode,

a base terminal of the second bipolar junction transistor is connected to a first terminal of the third resistor, and

a second terminal of the third resistor is connected to the ground potential.

16. The apparatus according to claim 15 , wherein the driver circuit further comprises a Zener diode connected between a source terminal of the one or more metal-oxide-semiconductor field effect transistors and a node formed by connection of the collector terminal of the first bipolar junction transistor, the collector terminal of the second bipolar junction transistor, and the gate terminal of the one or more metal-oxide-semiconductor field effect transistors, said Zener diode configured to limit a source-gate voltage of the one or more metal-oxide-semiconductor field effect transistors.

17. A method of providing a low power loss reverse polarity protection comprising:

coupling one or more metal-oxide-semiconductor field effect transistors in series between a supply voltage and a load connected to a ground potential;

generating a control voltage of sufficient magnitude relative to the supply voltage to switch the one or more metal-oxide-semiconductor field effect transistors into a conductive state; and

using one or more bipolar junction transistors to control application of the control voltage to gate terminals of the one or more metal-oxide-semiconductor field effect transistors to provide at least one of power switching, reverse polarity protection, power switching with reverse polarity protection, or over voltage inhibition for the load, wherein each of the one or more bipolar junction transistors has (i) a collector terminal connected to the gate terminals of the one or more metal-oxide-semiconductor field effect transistors and (ii) an emitter terminal connected via a diode to either the supply voltage or the ground potential.

18. An automotive electronic control module comprising:

at least one metal-oxide-semiconductor field effect transistor connected between a supply voltage and an output terminal;

a charge pump connected to said supply voltage and configured to generate a voltage of sufficient magnitude relative to the supply voltage to switch the at least one metal-oxide-semiconductor field effect transistor into a conductive state; and

a driver circuit coupled between the charge pump and the at least one metal-oxide-semiconductor field effect transistor, wherein the driver circuit (i) comprises at least one bipolar junction transistor having a collector terminal connected to a gate terminal of the at least one metal-oxide-semiconductor field effect transistor and an emitter terminal connected via a diode to either said supply voltage or a ground potential, and (ii) is configured to drive the at least one metal-oxide-semiconductor field effect transistor to provide one or more of power switching, reverse polarity protection, power switching with reverse polarity protection, or over voltage inhibition.