High side driver circuit with diagnostic output
First Claim
1. A driver circuit, comprising:
- a command voltage source;
an npn switching transistor having a collector, a base and an emitter, the base connected to the command voltage source, the emitter connected to ground;
a pnp switching transistor having a collector, a base, and an emitter, the base connected to the npn switching transistor collector;
an electrical energy source;
an internal voltage source connected between the electrical energy source and the pnp switching transistor emitter;
a power transistor having a drain, a source, and a gate, the drain connected to the electrical energy source through a sense resistor, the source connected to a load; and
a first resistor connected between the pnp switching transistor collector and the power transistor gate.
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Accused Products
Abstract
A high side driver circuit includes a command voltage source, a first switching transistor having a base connected to the command voltage source, an emitter connected to ground, and a collector connected to a second switching transistor base. The second switching transistor includes an emitter connected to an electrical energy source through an internal voltage source. A power transistor includes a gate connected to the second switching transistor collector through a resistor, a drain connected to the electrical energy source through a sense resistor, and a source connected to a load. A diagnostic circuit portion including a comparator establishes a diagnostic output voltage based upon the state of the power transistor and characteristics of the power transistor drain and source for indicating fault conditions of the driver circuit.
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Citations
18 Claims
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1. A driver circuit, comprising:
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a command voltage source; an npn switching transistor having a collector, a base and an emitter, the base connected to the command voltage source, the emitter connected to ground; a pnp switching transistor having a collector, a base, and an emitter, the base connected to the npn switching transistor collector; an electrical energy source; an internal voltage source connected between the electrical energy source and the pnp switching transistor emitter; a power transistor having a drain, a source, and a gate, the drain connected to the electrical energy source through a sense resistor, the source connected to a load; and a first resistor connected between the pnp switching transistor collector and the power transistor gate. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A driver circuit, comprising:
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an electrical energy source; a power transistor including a drain, a gate, and a source, the source connected to a load; a sense resistor connected between the electrical energy source and the power transistor drain; a first switching transistor having an emitter, a base, and a collector, the emitter connected to the electrical energy source, the base connected between the sense resistor and the power transistor drain; and a comparator including a positive input terminal, a negative input terminal and an output terminal, the positive input terminal connected with the power transistor gate, the negative input terminal connected with the first switching transistor collector and with the power transistor source. - View Dependent Claims (8, 9, 10, 11)
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12. A method of detecting a fault condition of a driver circuit including a power transistor having a drain, a gate and a source, the method comprising the steps of:
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(a) sensing a characteristic of the power transistor drain; (b) sensing a characteristic of the power transistor source; (c) establishing a voltage indicative of at least one of the characteristics sensed in steps (a) and (b); (d) establishing a voltage indicative of whether the power transistor is in an on state; (e) comparing the voltage established in step (c) with the voltage established in step (d); and (f) establishing a diagnostic output voltage based upon the comparison made in step (e). - View Dependent Claims (13, 14, 15, 16, 17, 18)
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Specification