Threshold detection with tap
First Claim
1. A controller for use in a power converter, comprising:
- a power switch including a drain, a source, a control input, and a tap, wherein the power switch further includes a first transistor coupled to a second transistor, wherein a drain of the first transistor is coupled to the drain of the power switch, wherein a source of the first transistor is coupled to the tap, wherein a source current at the source of the first transistor is responsive to a drain voltage at the drain of the first transistor when the drain voltage at the drain of the first transistor is less than a pinch off voltage of the first transistor, and wherein the source current at the source of the first transistor is substantially equal to a maximum current when the drain voltage at the drain of the first transistor is greater than the pinch off voltage;
a tap sense circuit coupled to the tap of the power switch, wherein the tap sense circuit provides an indicator signal indicative of a voltage at the tap or a current through the first transistor; and
a drive circuit coupled to receive the indicator signal from the tap sense circuit, wherein the drive circuit is further coupled to receive a feedback signal representative of an output quantity at an output of the power converter, wherein the drive circuit is coupled to generate a drive signal coupled to control switching of the power switch to regulate a transfer of energy from an input of the power converter to the output of the power converter in response to the indicator signal and in response to the feedback signal.
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Accused Products
Abstract
A controller for use in a power converter includes a power switch including a drain, a source, a control input, and a tap. The power switch includes a first transistor coupled to a second transistor, a drain of the first transistor is coupled to the drain of the power switch and the source of the first transistor is coupled to the tap. A tap sense circuit is coupled to the tap. A drive circuit is coupled to receive an indicator signal from the tap sense circuit. The indicator signal is indicative of a voltage at the tap or the current through the first transistor. The drive circuit is coupled to receive a feedback signal representative of an output quantity of the power converter. The drive circuit is coupled to generate a drive signal to control switching of the power switch in response to the indicator signal and the feedback signal.
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Citations
26 Claims
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1. A controller for use in a power converter, comprising:
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a power switch including a drain, a source, a control input, and a tap, wherein the power switch further includes a first transistor coupled to a second transistor, wherein a drain of the first transistor is coupled to the drain of the power switch, wherein a source of the first transistor is coupled to the tap, wherein a source current at the source of the first transistor is responsive to a drain voltage at the drain of the first transistor when the drain voltage at the drain of the first transistor is less than a pinch off voltage of the first transistor, and wherein the source current at the source of the first transistor is substantially equal to a maximum current when the drain voltage at the drain of the first transistor is greater than the pinch off voltage; a tap sense circuit coupled to the tap of the power switch, wherein the tap sense circuit provides an indicator signal indicative of a voltage at the tap or a current through the first transistor; and a drive circuit coupled to receive the indicator signal from the tap sense circuit, wherein the drive circuit is further coupled to receive a feedback signal representative of an output quantity at an output of the power converter, wherein the drive circuit is coupled to generate a drive signal coupled to control switching of the power switch to regulate a transfer of energy from an input of the power converter to the output of the power converter in response to the indicator signal and in response to the feedback signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A power converter, comprising:
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an energy transfer element coupled between an input of the power converter and an output of the power converter; a power switch coupled to the energy transfer element and the input of the power converter, wherein the power switch includes a drain, a source, a control input, and a tap, wherein the power switch further includes a first transistor coupled to a second transistor, wherein a drain of the first transistor is coupled to the drain of the power switch, wherein a source of the first transistor is coupled to the tap, wherein a source current at the source of the first transistor is responsive to a drain voltage at the drain of the first transistor when the drain voltage at the drain of the first transistor is less than a pinch off voltage of the first transistor, and wherein the source current at the source of the first transistor is substantially equal to a maximum current when the drain voltage at the drain of the first transistor is greater than the pinch off voltage; and a controller coupled to control the power switch, wherein the controller includes; a tap sense circuit coupled to sense the tap of the power switch, wherein the tap sense circuit is coupled to generate an indicator signal that is indicative of a voltage at the tap of the power switch or a current from the tap of the power switch; and a drive circuit coupled to receive the indicator signal from the tap sense circuit, wherein the drive circuit is further coupled to receive a feedback signal representative of an output quantity at the output of the power converter, wherein the drive circuit is coupled to generate a drive signal coupled to control switching of the power switch to regulate a transfer of energy from the input of the power converter to the output of the power converter in response to the indicator signal and in response to the feedback signal. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26)
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Specification