Current sensing on a MOSFET
First Claim
1. A device comprising:
- a switched power converter comprising;
a first converter circuit comprising an output terminal;
a second converter circuit comprising an input terminal; and
an inductor configured to connect the output terminal of the first converter circuit to the input terminal of the second converter circuit; and
a current sensing circuit configured to measure a voltage at a sense input, the sense input of the current sense circuit connected to a first sense terminal via a first diode and connected to a second sense terminal via a second diode, whereinthe first sense terminal is connected to the output terminal of the first converter circuit, andthe second sense terminal is connected to the input terminal of the second converter circuit.
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Accused Products
Abstract
A device having a switch with a voltage applied across the switch. A current sensing circuit is connected to one terminal of the switch. The current sensing circuit receives power independently of the voltage applied across the switch. The power supply shares the other terminal of the switch with the current sensing circuit. The switch is adapted for opening and closing. When the switch closes, the current sensing circuit senses current through the switch and upon opening the switch the high voltage of the switch is blocked from the current sensing circuit. The sense current is caused to flow from the current sensing circuit to the other terminal when the switch is closed. The flow of the sense current produces a voltage which is compared differentially to another voltage referenced by the other terminal.
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Citations
20 Claims
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1. A device comprising:
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a switched power converter comprising; a first converter circuit comprising an output terminal; a second converter circuit comprising an input terminal; and an inductor configured to connect the output terminal of the first converter circuit to the input terminal of the second converter circuit; and a current sensing circuit configured to measure a voltage at a sense input, the sense input of the current sense circuit connected to a first sense terminal via a first diode and connected to a second sense terminal via a second diode, wherein the first sense terminal is connected to the output terminal of the first converter circuit, and the second sense terminal is connected to the input terminal of the second converter circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method comprising:
sensing, with a current sensing circuit, current in a switched power converter, wherein the switched power converter comprises a first converter circuit, a second converter circuit, a common rail, and an inductor connecting an output terminal of the first converter circuit to an input terminal of a second converter circuit, wherein the current sensing circuit comprises a supply voltage terminal having a predetermined voltage, and wherein the sensing of the current comprises; sensing, with the current sense circuit, a first voltage across a first MOSFET connected in the first converter circuit between the output terminal and the common rail; sensing, with the current sensing circuit, a second voltage across a second MOSFET connected in the second converter circuit between the input terminal and the common rail; isolating the current sensing circuit from the first voltage when the first voltage is greater than the predetermined voltage; and isolating the current sensing circuit from the second voltage when the second voltage is greater than the predetermined voltage. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. A circuit comprising:
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an inductor having a first inductor terminal and a second inductor terminal; a first switch having a first switch terminal connected to the first inductor terminal and a second switch terminal directly connected to a ground terminal, wherein the first switch connects and disconnects the first switch terminal to the second switch terminal; a second switch having a third switch terminal connected to the second inductor terminal and a fourth switch terminal directly connected to the ground terminal, wherein the second switch connects and disconnects the third switch terminal to the fourth switch terminal; and a current sensing circuit comprising; a first sense terminal connected to the first inductor terminal; a second sense terminal connected to the second inductor terminal; and a sense circuit configured to measure a voltage at a sense input, the sense input of the sense circuit connected to the first sense terminal via a first diode and connected to the second sense terminal via a second diode. - View Dependent Claims (20)
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Specification