Method for operating a switching element connected in parallel with a rectifier element and electronic circuit

Patent metadata

Field	Value
Publication number	US-2025364974-A1
Application number	US-202519205295-A
Country	US
Kind code	A1
Filing date	May 12, 2025
Priority date	May 22, 2024
Publication date	Nov 27, 2025
Grant date	—

Abstract

Disclosed is a method for operating a switching element connected in parallel with a rectifier element and an electronic circuit. The method includes charging a capacitor coupled to load path nodes of an electronic switch, wherein the electronic switch includes a switching element and a rectifier element connected in parallel with a load path of the switching element and between the load path nodes; allowing the capacitor to be discharged via the load path nodes of the electronic switch; and comparing a capacitor voltage across the capacitor with a first voltage level.

First claim

1 . A method, comprising:
charging a capacitor coupled to load path nodes of an electronic switch, wherein the electronic switch comprises a switching element and a rectifier element connected in parallel with a load path of the switching element and between the load path nodes; allowing the capacitor to be discharged via the load path nodes of the electronic switch; and comparing a capacitor voltage across the capacitor with a first voltage level.

2 . The method according to claim 1 , further comprising:
switching on and off the electronic switch in accordance with a predefined control signal.

3 . The method according to claim 2 , further comprising:
detecting a time instance when the capacitor voltage reaches the first voltage level; and determining a time difference between the detected time instance and a time instance at which the first electronic switch switches on.

4 . The method according to claim 3 , further comprising:
detecting that the electronic switch operates under zero voltage switching (ZVS) conditions when the determined time difference is longer than or equal to a predefined time period; and detecting that the electronic switch does not operate under ZVS conditions when the determined time difference is shorter than the predefined time period.

5 . The method according to claim 2 , further comprising:
detecting that the electronic switch does not operate under zero voltage switching (ZVS) conditions when the capacitor voltage during an off-state of the electronic switch does not reach the first voltage level V 21 .

6 . The method according to claim 1 , further comprising:
detecting a time instance when the capacitor voltage reaches the first voltage level; and switching on the electronic switch after a predefined delay time after the detected time instance.

7 . The method according to claim 1 ,
wherein charging the capacitor comprises charging the capacitor when the switching element is in an off-state.

8 . The method according to claim 1 ,
wherein the capacitor being coupled to the load path nodes of the electronic switch comprises the capacitor being coupled to the load path nodes via a coupling circuit, wherein the coupling circuit is configured to discharge the capacitor when a voltage between the load path nodes is lower than a voltage across the capacitor.

9 . The method according to claim 1 ,
wherein charging the capacitor comprises charging the capacitor until the voltage across the capacitor reaches a second voltage level higher than the first voltage level.

10 . The method according to claim 1 , further comprising:
connecting the capacitor to a charging circuit when the switching element is in an on-state; monitoring the voltage across the capacitor when the switching element is in the on-state; and switching off the switching element when the voltage across the capacitor reaches a third voltage level.

11 . The method according to claim 10 ,
wherein the electronic switch is connected in series with a further electronic switch to form a half bridge; and wherein the method further comprises switching off the switching element in the electronic switch before switching on the further electronic switch.

12 . The method according to claim 11 ,
wherein an inductive circuit is connected between the load path nodes of the electronic switch.

13 . The method according to claim 1 ,
wherein the switching element and the rectifier element each are an integral part of the electronic switch.

14 . An electronic circuit, comprising:
an electronic switch comprising load path nodes, a switching element configured to be operated in an on-state or an off-state, and a rectifier element connected in parallel with a load path of the switching element and between the load path nodes; a capacitor coupled to the load path nodes of the electronic switch; a charging circuit coupled to the capacitor; and a control circuit configured to control the charging circuit such that the charging circuit charges the capacitor when the switching element is in the off-state, and compare a capacitor voltage across the capacitor with a first voltage level.

15 . The electronic circuit according to claim 14 , wherein the control circuit is further configured to switch on and off the electronic switch in accordance with a predefined control signal.

16 . The electronic circuit according to claim 15 , wherein the control circuit is further configured to:
detect a time instance when the capacitor voltage reaches the first voltage level, and determine a time difference between the detected time instance and a time instance at which the first electronic switch switches on.

17 . The electronic circuit according to claim 16 , wherein the control circuit is further configured to:
detect that the electronic switch operates under zero voltage switching (ZVS) conditions when the determined time difference is longer than a predefined time period, and detect that the electronic switch does not operate under ZVS conditions when the determined time difference is shorter than the predefined time period.

18 . The electronic circuit according to claim 17 ,
wherein the control circuit comprises a communication output, and wherein the control circuit is configured to communicate through the communication output whether or not the electronic switch operates under ZVS conditions.

19 . The electronic circuit according to claim 14 , wherein the control circuit is further configured to detect that the electronic switch does not operate under zero voltage switching (ZVS) conditions when the capacitor voltage during the off-state of the electronic switch does not reach the first voltage level.

Assignees

• Infineon Technologies Austria Ag

Inventors

• Qiu Yuqiang
• Tian Bin

Classifications

• H03K17/60

  the devices being bipolar transistors (bipolar transistors having four or more electrodes H03K17/72) · CPC title

• H03K17/133

  in field-effect transistor switches · CPC title

• H03K3/012 Primary

  Modifications of generator to improve response time or to decrease power consumption · CPC title

• H03K17/13 Primary

  Modifications for switching at zero crossing (generating an impulse at zero crossing H03K5/1536) · CPC title

• H02M3/07

  using capacitors charged and discharged alternately by semiconductor devices with control electrode {, e.g. charge pumps} · CPC title