Turn-off of power switching device

Patent metadata

Field	Value
Publication number	US-2019319615-A1
Application number	US-201816119902-A
Country	US
Kind code	A1
Filing date	Aug 31, 2018
Priority date	Apr 16, 2018
Publication date	Oct 17, 2019
Grant date	—

Abstract

A system includes a storage capacitor coupled between an input voltage source and a ground terminal, a voltage sensing circuit coupled to the input voltage source and to the storage capacitor, a first transistor coupled to the voltage sensing circuit, a current mirror circuit coupled to the first transistor, a diode coupled between the storage capacitor and the current mirror circuit, and a second transistor configured to couple between a gate of a power switching device and the ground terminal. A gate of the second transistor is coupled to the storage capacitor by way of the voltage sensing circuit.

First claim

1 . A system, comprising:
a storage capacitor coupled between an input voltage source and a ground terminal; a voltage sensing circuit coupled to the input voltage source and to the storage capacitor; a first transistor coupled to the voltage sensing circuit; a current mirror circuit coupled to the first transistor; a diode coupled between the storage capacitor and the current mirror circuit; and a second transistor configured to couple between a gate of a power switching device and the ground terminal, wherein a gate of the second transistor is coupled to the storage capacitor by way of the voltage sensing circuit.

2 . The system of claim 1 wherein the power switching device is an n-type metal-oxide-semiconductor field effect transistor.

3 . The system of claim 1 further comprising a p-type metal-oxide-semiconductor field effect transistor coupled between the storage capacitor and the input voltage source.

4 . The system of claim 1 wherein the voltage sensing circuit comprises an n-type metal-oxide-semiconductor field effect transistor (MOSFET) coupled to the ground terminal and a p-type MOSFET coupled to the n-type MOSFET and the storage capacitor, wherein the input voltage source is coupled to a gate of both the n-type and p-type MOSFETs.

5 . The system of claim 4 wherein the first transistor comprises an n-type MOSFET, and wherein a gate of the first transistor is coupled to a node between the n-type and p-type MOSFETs of the voltage sensing circuit.

6 . The system of claim 4 wherein the second transistor comprises an n-type MOSFET, and wherein the gate of the second transistor is coupled to a node between the n-type and p-type MOSFETs of the voltage sensing circuit.

7 . The system of claim 6 wherein the gate of the second transistor is configured to couple to the storage capacitor in response to an input voltage source voltage being below a threshold.

8 . The system of claim 1 wherein:
the current mirror circuit further comprises first and second p-type metal-oxide-semiconductor field effect transistors (MOSFETs);
a gate of the first p-type MOSFET is coupled to a gate of the second p-type MOSFET, which is in turn coupled to a drain of the second p-type MOSFET and to the first transistor;
sources of both the first and second p-type MOSFETs are coupled to the gate of the power switching device; and
a drain of the first p-type MOSFET is coupled to the diode.

9 . The system of claim 1 further comprising an n-type metal-oxide-semiconductor field effect transistor (MOSFET) coupled between the gate of the power switching device and the ground terminal, wherein a gate of the n-type MOSFET is coupled to an inverted power enable input.

10 . A system, comprising:
a storage capacitor coupled between an input voltage source and a ground terminal; a voltage sensing circuit coupled to the input voltage source and to the storage capacitor; a first transistor coupled to the voltage sensing circuit and to the storage capacitor; a current mirror circuit coupled to the first transistor; a diode coupled between the storage capacitor and the current mirror circuit; and a second transistor configured to couple between a gate of a power switching device and the input voltage source, wherein a gate of the second transistor is coupled to the storage capacitor.

11 . The system of claim 10 wherein the power switching device is a p-type metal-oxide-semiconductor field effect transistor.

12 . The system of claim 10 wherein:
the voltage sensing circuit comprises a p-type metal-oxide-semiconductor field effect transistor (MOSFET);
the storage capacitor is coupled to the input voltage source by way of the voltage sensing circuit; and
a source of the p-type MOSFET is coupled to the input voltage source and a gate of the p-type MOSFET is coupled to the ground terminal.

13 . The system of claim 10 wherein the first transistor comprises a p-type metal-oxide-semiconductor field effect transistor.

14 . The system of claim 10 wherein the second transistor comprises a p-type metal-oxide-semiconductor field effect transistor.

15 . The system of claim 10 wherein:
the current mirror circuit further comprises first and second n-type metal-oxide-semiconductor field effect transistors (MOSFETs);
a gate of the first n-type MOSFET is coupled to a gate of the second n-type MOSFET, which is in turn coupled to a drain of the second n-type MOSFET and to the first transistor;
sources of both the first and second p-type MOSFETs are coupled to the gate of the power switching device; and
a drain of the first p-type MOSFET is coupled to the diode.

16 . The system of claim 10 further comprising a p-type metal-oxide-semiconductor field effect transistor (MOSFET) coupled between the gate of the power switching device and the input voltage source, wherein a gate of the p-type MOSFET is coupled to a power enable input.

17 . A system, comprising:
a regenerative current feedback loop; a voltage sensing circuit coupled to the regenerative current feedback loop and configured to activate the regenerative current feedback loop when an input voltage source drops below a threshold; a storage capacitor coupled to the regenerative current feedback loop, wherein in response to being activated, the regenerative current feedback loop is configured to charge the storage capacitor from a gate capacitance of a power switching device; and a gate pull-down device configured to couple a gate of the power switching device to a ground terminal in response to the storage capacitor becoming increasingly charged.

18 . The system of claim 17 wherein the power switching device is an n-type metal-oxide-semiconductor field effect transistor.

19 . The system of claim 17 further comprising a p-type metal-oxide-semiconductor field effect transistor coupled between the storage capacitor and the input voltage source.

20 . The system of claim 17 wherein the voltage sensing circuit comprises an n-type metal-oxide-semiconductor field effect transistor (MOSFET) coupled to the ground terminal and a p-type MOSFET coupled to the n-type MOSFET and the storage capacitor, wherein the input voltage source is coupled to a gate of both the n-type and p-type MOSFETs.

21 . (canceled)

22 . The system of claim 20 wherein the gate pull-down device comprises an n-type MOSFET, and wherein the gate of the gate pull-down device is coupled to a node between the n-type and p-type MOSFETs of the voltage sensing circuit.

23 . The system of claim 17 wherein:
the current mirror circuit further comprises first and second p-type metal-oxide-semiconductor field effect transistors (MOSFETs);
a gate of the first p-type MOSFET is coupled to a gate of the second p-type MOSFET, which is in turn coupled to a drain of the second p-type MOSFET and to the first transistor;
sources of both the first and second p-type MOSFETs are coupled to the gate of the power switching device; and
a drain of the first p-type MOSFET is coupled to the storage capacitor.

Assignees

• Texas Instruments Inc

Inventors

• Choi Jae Won
• Turkson Richard

Classifications

• H03K17/0822 Primary

  in field-effect transistor switches · CPC title

• H03K17/08122 Primary

  in field-effect transistor switches · CPC title

• H01L27/0629

  Electricity · mapped topic

• H10D84/811

  Combinations of field-effect devices and one or more diodes, capacitors or resistors · CPC title