Bootstrap diode circuits

Patent metadata

Field	Value
Publication number	US-2016359483-A1
Application number	US-201514733655-A
Country	US
Kind code	A1
Filing date	Jun 8, 2015
Priority date	Jun 8, 2015
Publication date	Dec 8, 2016
Grant date	—

Abstract

Bootstrap diode circuits are disclosed. Example bootstrap diode circuits disclosed herein include a first diode having a first diode input coupled to a voltage supply and a first diode output. Disclosed bootstrap diode circuits additionally include a second diode having a second diode input coupled to the first diode output and a second diode output and a plurality of zener diodes coupled in series. The plurality of series-coupled zener diodes are further coupled in parallel with the second diode.

First claim

What is claimed is:

1 . A bootstrap diode circuit on an integrated circuit comprising:
a first diode having a first diode input coupled to a voltage supply and a first diode output; a second diode having a second diode input coupled to the first diode output and a second diode output; and a plurality of zener diodes coupled in series, the plurality of zener diodes being coupled in parallel with the second diode.

2 . A bootstrap diode circuit as defined in claim 1 in which an area of the second diode is six times greater than an area of the first diode.

3 . A bootstrap diode circuit as defined in claim 1 in which the bootstrap diode circuit further includes a MOSFET coupled in parallel with the first diode.

4 . A bootstrap diode circuit as defined in claim 1 in which the plurality of zener diodes is a first plurality of zener diodes, and the bootstrap diode circuit includes a second plurality of zener diodes coupled in series, the second plurality of zener diodes being coupled in parallel with the first diode.

5 . A bootstrap diode circuit as defined in claim 4 in which the bootstrap diode circuit further includes a first MOSFET coupled in parallel with the first diode and a second MOSFET coupled in parallel with the second diode.

6 . A bootstrap diode circuit as defined in claim 5 in which the first MOSFET and the second MOSFET are N-MOSFETS.

7 . A bootstrap diode circuit as defined in claim 5 in which the first MOSFET is an N-MOSFET and the second MOSFET is a P-MOSFET.

8 . A bootstrap diode circuit as defined in claim 5 in which the bootstrap diode circuit further includes a voltage limiting circuit coupled between a gate terminal of the first MOSFET and a source terminal of the first MOSFET, the voltage limiting circuit including a zener diode coupled in series with a resistor.

9 . A bootstrap diode circuit as defined in claim 3 in which the bootstrap diode circuit further includes a boost driver circuit, the boost driver circuit including:
a voltage sensing circuit having a first input coupled to the first output of the gate driver circuit and a first voltage sensing output and a second voltage sensing output;
a comparator circuit having a first comparator input and a second comparator input coupled to the first voltage sensing output of the voltage sensing circuit and the second voltage sensing output of the voltage sensing circuit, respectively; and
a charge pump circuit having a first charge pump input and a second charge pump input coupled to a first comparator output and a second comparator output, respectively, the charge pump circuit having a first charge pump output coupled to a gate of the MOSFET.

10 . A method to drive a switching device, comprising:
charging a charging device coupled to a switching device; turning on the switching device by delivering charge from the charging device to the switching device, to cause a reverse bias voltage to be applied to a bootstrap diode circuit, the bootstrap diode circuit having first and second diodes coupled in series, and the first and second diodes having respective reverse bias voltage ratings; blocking, with the first and second diodes, the reverse bias voltage, the magnitude of the reverse bias voltage exceeding the respective reverse bias voltages of the first and second diodes.

11 . (canceled)

12 . (canceled)

13 . A method as defined in claim 10 in which the reverse bias voltage ratings of the first and second diode are equal.

14 . A method as defined in claim 10 in which the second diode is coupled to an output of the bootstrap diode circuit, the reverse bias voltage being applied at the output of the bootstrap diode circuit, and a first area associated with the first diode is six times smaller than a second area associated with the second diode.

15 . A method as defined in claim 10 , in which the second diode is coupled to an output of the bootstrap diode circuit, the reverse bias voltage being applied at the output of the bootstrap diode circuit, and the bootstrap diode circuit further includes a plurality of zener diodes coupled in series, the plurality of zener diodes being coupled in parallel with the second diode, the method further comprising clamping, with the plurality of zener diodes, the voltage drop across the second diode to a magnitude less than or equal to the reverse bias voltage rating of the second diode.

16 . A method as defined in claim 15 , in which the switching device is a first switching device, and the diode circuit further includes a second switching device coupled in parallel with the first diode, the method further comprising:
turning on the second switching device when charging the charging device.

17 . A method as defined in claim 10 , in which the switching device is a first switching device, and the diode circuit further includes a second switching device coupled in parallel with the first diode, and a third switching device coupled in parallel with the second diode, the method further comprising:
turning on the second switching device and the third switching device when charging the charging device.

18 . A method as defined in claim 10 in which the diode circuit further includes a first plurality of zener diodes coupled in series, the first plurality of zener diodes being coupled in parallel with the first diode, a second plurality of zener diode coupled in series, the second plurality of zener diodes being coupled in parallel with the second diode, and the method further including:
clamping, with the first plurality of zener diodes, the voltage across the first diode to a magnitude less than or equal to the reverse bias voltage rating of the first diode; and
clamping, with the second plurality of zener diodes, the voltage across the second diode to a magnitude less than or equal to the reverse bias voltage rating of the second diode.

19 . A method as defined in claim 18 in which the switching device is a first switching device, the diode circuit further including
a second switching device coupled in parallel with the first diode, and a third switching device coupled in parallel with the second diode, the method further including turning on the second switching device and the third switching device when charging the charging device.

20 . (canceled)

21 . (canceled)

22 . (canceled)

23 . (canceled)

24 . (canceled)

25 . A switch controller disposed on an integrated circuit comprising:
a gate driver circuit to control first and second switches; and a bootstrap circuit coupled to the gate driver circuit, the bootstrap circuit having a diode circuit including a first diode and a second diode coupled in series, the diode circuit to block a reverse bias voltage having a magnitude that exceeds a first reverse bias voltage rating of the first diode and that exceeds a second reverse bias voltage rating of the second diode.

26 . (canceled)

27 . (canceled)

28 . (canceled)

29 . A switch controller as defined in claim 25 in which the reverse bias voltage is applied to an output of the second diode, and the diode circuit further includes a plurality of zener diodes coupled in series, the zener diodes being coupled in parallel with the second diode.

30 . A switch controller as defined in claim 29 in which the reverse bias voltage is applied to an output of the s

Assignees

• Texas Instruments Inc

Inventors

• Mukhopadhyay Rajarshi
• Schemm Nathan
• Wang Xiaonan

Classifications

• G05F1/46

  wherein the variable actually regulated by the final control device is DC (G05F1/625 takes precedence) · CPC title

• H03K5/2472

  using field effect transistors (H03K5/2436 takes precedence) · CPC title

• H03K17/74 Primary

  by the use, as active elements, of diodes (by the use of more than one type of semiconductor device H03K17/567; by the use of tunnel diodes H03K17/58; by the use of negative resistance diodes H03K17/70) · CPC title

• H03K2217/0081

  Power supply means, e.g. to the switch driver · CPC title