US 11,146,257 B2 · Latching DC switch circuit with overcurrent protection using field effect transistors

Abstract

An overcurrent protection circuit includes switches, resistors, and a voltage divider. A first switch includes a first control terminal and switches current to a load. The first resistor is connected in series with the first switch. The second resistor is connected in series with a second control terminal of the second switch and an output terminal of the overcurrent protection circuit. The voltage divider is connected in series with the second switch and has a center terminal connected to the first control terminal. A DC source voltage is across the second switch and the voltage divider. A latching circuit is provided by the switches, the voltage divider, the first resistor and the load. The second switch discharges the first switch to limit current to the output terminal in response to a voltage drop across the first resistor indicating current supplied to the output terminal has exceeded a threshold.

Claims20

Dependent claims

An overcurrent protection circuit comprising:

a first switch comprising a first control terminal and configured to switch current to a load ON and OFF;
a first resistor connected in series with the first switch;
a second switch comprising a second control terminal;
a second resistor connected in series with the second control terminal and an output terminal of the overcurrent protection circuit;
and
a voltage divider connected in series with the second switch and having a center terminal, wherein the center terminal is connected to the first control terminal,
wherein
a direct current source voltage is received across the second switch and the voltage divider,
a latching circuit is provided by the second switch and the voltage divider being connected in parallel with the first switch, the first resistor and the load, and
the second switch discharges the first switch to limit current to the output terminal in response to a voltage drop across the first resistor indicating current supplied to the output terminal has exceeded a predetermined threshold.

7 more elements

An overcurrent protection circuit system comprising:

a first metal-oxide-semiconductor field effect transistor (MOSFET) comprising a first gate and configured to switch current to a load ON and OFF;
a first resistor connected in series with the first MOSFET;
a second MOSFET comprising a second gate;
a second resistor connected in series with the second gate and an output terminal, wherein the output terminal is connected between the first resistor and the load and provides an output voltage to the load;
and
a voltage divider connected in series with the second MOSFET and having a center terminal, wherein the center terminal is connected to the first gate,
wherein
a source voltage is received across the second MOSFET and the voltage divider,
a latching circuit is provided by the second MOSFET and the voltage divider being connected in parallel with the first MOSFET, the first resistor and the load, and
the second MOSFET discharges the first MOSFET based on a voltage drop across the first resistor to limit current to the output terminal.

7 more elements

Dependencies are inferred from the claim text.

Latching DC switch circuit with overcurrent protection using field effect transistors

Life of this patent

Latching DC switch circuit with overcurrent protection using field effect transistors

Life of this patent

Abstract

Claims20