Protected switching element

Patent metadata

Field	Value
Publication number	US-2016204776-A1
Application number	US-201514594957-A
Country	US
Kind code	A1
Filing date	Jan 12, 2015
Priority date	Jan 12, 2015
Publication date	Jul 14, 2016
Grant date	—

Abstract

A circuit is suggested comprising an electronic switching element, a logic unit coupled to control the electronic switching element, and a counter unit coupled to the logic unit, wherein the counter unit comprises a counter and an internal power supply.

First claim

1 . A circuit comprising
an electronic switching element, a logic unit coupled to control the electronic switching element, a counter unit coupled to the logic unit, wherein the counter unit comprises a counter and an internal power supply.

2 . The circuit according to claim 1 , wherein the internal power supply is arranged to provide power to the counter unit in case an external supply voltage for the circuit gets interrupted.

3 . The circuit according to claim 1 , wherein the electronic switching element comprises at least one transistor with a current sense unit, wherein the current sense unit is connected to the logic unit.

4 . The circuit according to claim 1 , wherein the counter unit comprises a supply decoupling unit that is coupled to the internal power supply, wherein the supply decoupling unit is arranged
to determine an interruption in the external supply voltage and based on such interruption to decouple the external supply voltage from the counter unit such that the counter unit is buffered by the internal power supply.

5 . The circuit according to claim 4 , wherein the supply decoupling unit and the internal power supply are coupled to a supply supervision unit, wherein the supply supervision unit is arranged to issue a signal to reset the counter.

6 . The circuit according to claim 5 , wherein the supply supervision unit is arranged to issue the signal to reset the counter in case the power provided by the internal power supply reaches and/or falls below a predetermined threshold.

7 . The circuit according to claim 5 , wherein the supply supervision unit is arranged to stop issuing the signal to reset the counter in case the external supply voltage has been switched on.

8 . The circuit according to claim 5 , wherein the supply supervision unit is arranged to stop issuing the signal to reset the counter a predetermined time after an enablement of the external supply voltage has been detected.

9 . The circuit according to claim 1 , wherein the counter unit comprises an input for resetting the counter.

10 . The circuit according to claim 1 , wherein the counter of the counter unit is arranged for counting events, wherein signals corresponding to events are supplied by the logic unit.

11 . The circuit according to claim 10 , wherein the event may be at least one of the following:
an over-temperature condition, a temperature difference excess, an over-current condition, an overload condition, a fault condition, any preferred signal or event.

12 . The circuit according to claim 10 , wherein the counter unit comprises a first comparing unit determining whether the counted events reach a predetermined threshold.

13 . The circuit according to claim 10 , wherein the counter unit comprises a second comparing unit determining whether the counted events is zero or different from zero.

14 . The circuit according to claim 1 , wherein the counter unit comprises a storage element for storing at least one information, wherein the internal power supply is arranged to provide power for buffering the at least one information in case an external supply voltage for the circuit gets interrupted.

15 . The circuit according to claim 1 , wherein the internal power supply comprises at least one capacitor that is charged via an external supply voltage.

16 . The circuit according to claim 1 , wherein the electronic switching element is implemented as a high-side switch or as a low-side switch.

17 . A device comprising at least one circuit according to claim 1 .

18 . The device according to claim 17 , wherein the device is a protected field effect transistor.

19 . A method for operating a circuit according to claim 1 , the method comprising:
determining an interruption in an external supply voltage, based on such interruption, decoupling the external supply voltage from the counter unit such that the counter unit is buffered by the internal power supply.

20 . The method according to claim 19 comprising:
counting events by the counter of the counter unit, wherein signals corresponding to events are supplied by the logic unit.

21 . The method according to claim 19 comprising:
issuing a signal to reset the counter in case the power provided by the internal power supply reaches and/or falls below a predetermined threshold.

22 . The method according to claim 19 comprising:
stop issuing the signal to reset the counter a predetermined time after an enablement of the external supply voltage has been detected.

23 . A device comprising:
means for determining an interruption in an external supply voltage, based on such interruption, means for decoupling the external supply voltage from a counter unit such that the counter unit is buffered by an internal power supply.

Assignees

• Infineon Technologies Ag

Inventors

• Brugger Florian
• Illing Robert
• Mayer Alexander
• Djelassi Christian

Classifications

• H03K17/24

  Storing the actual state when the supply voltage fails · CPC title

• H03K17/20

  Modifications for resetting core switching units to a predetermined state · CPC title

• H03K17/0822 Primary

  in field-effect transistor switches · CPC title

• H03K2017/0806

  against excessive temperature · CPC title

• H03K17/08 Primary

  Modifications for protecting switching circuit against overcurrent or overvoltage · CPC title