Method of controlling the switching DI/DT and DV/DT of a MOS-gated power transistor
First Claim
1. A control circuit for controlling the switching di/dt and switching dv/dt of a MOS gate controlled power device, said MOS gate controlled device providing a supply voltage to a load circuit;
- said control circuit comprising;
a current generator circuit having an output coupled to a gate terminal of said MOS gate controlled device for supplying a current to said gate terminal;
a first resistor having a first resistance and being coupled to a source terminal of said MOS gate controlled device;
a second resistor having a second resistance and coupled to said source terminal; and
a switching circuit for coupling a common terminal of said current generator circuit to a respective one of said first and second resistors for controlling the switching dv/dt and for coupling said common terminal to another of said first and second resistors for controlling the switching di/dt.
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Accused Products
Abstract
The switching di/dt and switching dv/dt of a MOS gate controlled ("MOS-gated") power device are controlled by respectively controlling the voltage and current waveforms. Open loop control of the turn-on of the MOS-gated device is provided by coupling a common terminal of a current generator circuit, which provides a current to the gate of the MOS device, to a first resistor for controlling the switching dv/dt. At the detection of a negative dv/dt, the common terminal of the current generator circuit is then coupled to a second resistor for controlling the switching di/dt. The first and second resistors are, in turn, coupled to the source terminal fo the MOS-gated device. An analogous operation provides turn-off control of the MOS-gated power device. Closed loop control is also provided by measuring the switching dv/dt and the switching di/dt which are then fed back to the circuit to control the current supplied to the gate of the MOS-gated device. The switching di/dt can be measured by measuring the voltage difference across the length of a calibrated wire bond having a predetermined length and diameter.
58 Citations
22 Claims
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1. A control circuit for controlling the switching di/dt and switching dv/dt of a MOS gate controlled power device, said MOS gate controlled device providing a supply voltage to a load circuit;
- said control circuit comprising;
a current generator circuit having an output coupled to a gate terminal of said MOS gate controlled device for supplying a current to said gate terminal; a first resistor having a first resistance and being coupled to a source terminal of said MOS gate controlled device; a second resistor having a second resistance and coupled to said source terminal; and a switching circuit for coupling a common terminal of said current generator circuit to a respective one of said first and second resistors for controlling the switching dv/dt and for coupling said common terminal to another of said first and second resistors for controlling the switching di/dt. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
- said control circuit comprising;
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15. A method of controlling the switching di/dt and switching dv/dt of a MOS gate controlled device;
- said MOS gate controlled device controlling a supply voltage to a circuit;
said method comprising the steps of;providing a current generator circuit for supplying a current to a gate of said MOS gate controlled power device; coupling a common terminal of said current generator circuit to a first resistor which is coupled to a source terminal of said MOS device for supplying a first current to said gate of said MOS gate controlled device and thereby controlling the switching dv/dt of said circuit; decoupling said current generator circuit from said first resistor and coupling said current generator circuit to a second resistor for supplying a second current to said gate and thereby controlling the switching di/dt of said circuit; and terminating the supply of said second current when said gate voltage reaches a predetermined value. - View Dependent Claims (16, 17)
- said MOS gate controlled device controlling a supply voltage to a circuit;
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18. A method of controlling the switching di/dt and dv/dt of a MOS gate controlled device;
- said MOS gate controlled device controlling a supply voltage to a load circuit;
said method comprising the steps of;discharging a gate terminal of said MOS gate controlled device by coupling a common terminal of a current generator circuit to a first resistor which is coupled to a source terminal of said MOS gate controlled device and thereby controlling the rate of discharge; decoupling said current generator circuit from said first resistor and coupling said current generator to a second resistor and thereby controlling said switching di/dt of said circuit; and clamping said gate terminal when the voltage at said gate terminal is below a predetermined value. - View Dependent Claims (19, 20)
- said MOS gate controlled device controlling a supply voltage to a load circuit;
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21. A control circuit for controlling the switching di/dt and the switching dv/dt of a MOS gate controlled device formed in a substrate, said MOS gate controlled device providing a supply voltage to a load circuit;
- said control circuit comprising;
a current generator circuit having an output coupled to a gate terminal of said MOS gate controlled device for supplying a current thereto; a calibrated wire bond having a predetermined length and diameter and coupled to one of a source terminal and a drain terminal of said MOS gate controlled device; and a feed back circuit for controlling the current supplied by said current generator circuit as a function of a value of the di/dt measured across said wire bond. - View Dependent Claims (22)
- said control circuit comprising;
Specification