Electronic Switching and Protection Circuit with Wakeup Function

• US 20170294774A1
• Filed: 04/08/2016
• Published: 10/12/2017
• Est. Priority Date: 04/08/2016
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Illing, Robert, Djelassi, Christian, Ladurner, Markus, Jansson, David
• Granted Patent: US 10,170,905 B2
• Time in Patent Office: Days
• CPC Class Codes: H02H 3/087 for dc applications
• CPC Class Codes: H02H 3/0935 the timing being determined by numerical means
• CPC Class Codes: H02H 3/10 additionally responsive to some other abnormal electrical conditions
• CPC Class Codes: H02H 3/202 for dc systems
• CPC Class Codes: H02H 5/041 additionally responsive to excess current H02H5/048 takes precedence
• CPC Class Codes: H02H 6/005 using digital thermal images
• CPC Class Codes: H02H 9/025 Current limitation using field effect transistors
• CPC Class Codes: H03M 1/12 Analogue/digital converters H03M1/001 – H03M1/10 take precedence
• CPC Class Codes: H03M 1/365 the voltage divider being a single resistor string

Abstract

An embodiment electronic circuit includes an electronic switch comprising a load path, and a control circuit configured to drive the electronic switch. The control circuit is configured to operate in one of a first operation mode and a second operation mode based at least on a level of a load current of the electronic switch. In the first operation mode the control circuit is configured to generate a first protection signal based on a current-time-characteristic of the load current and drive the electronic switch based on the first protection signal. The control circuit is configured to generate a status signal such that the status signal has a wakeup pulse when the operation mode changes from the second operation mode to the first operation mode and, after the wakeup pulse, a signal level representing a level of the load current.

Claims

1. An electronic circuit, comprising:

an electronic switch comprising a load path; and

a control circuit configured to drive the electronic switch,

wherein the control circuit is configured to operate in one of a first operation mode and a second operation mode based at least on a level of a load current of the electronic switch,

wherein in the first operation mode the control circuit is configured to generate a first protection signal based on a current-time-characteristic of the load current and drive the electronic switch based on the first protection signal, and

wherein the control circuit is configured to generate a status signal such that the status signal has a wakeup pulse when the operation mode changes from the second operation mode to the first operation mode and, after the wakeup pulse, a signal level representing a level of the load current.

2. The electronic circuit of claim 1, wherein the control circuit is configured, in the first operation mode, to continuously output the signal level representing the level of the load current at a status output of the electronic circuit.

3. The electronic circuit of claim 1, wherein the control circuit is configured

to receive a polling signal;

and

in the first operation mode, to output the signal level representing the level of the load current only upon request by the polling signal.

4. The electronic circuit of claim 3, wherein the control circuit is further configured, in the second operation mode, to output a status pulse different from the wakeup pulse upon request by the polling signal.

5. The electronic circuit of claim 1, wherein the control circuit is configured to change operation from the second operation mode to the first operation mode when the load current reaches a predefined threshold.

6. The electronic circuit of claim 1, wherein the control circuit comprises a first protection circuit configured to generate the first protection signal and comprising:

an analog-to-digital converter (ADC) configured to receive an ADC input signal representing the load current and to output an ADC output signal that includes a sequence of values such that each of the values represents a respective sample of the ADC input signal;

a filter configured to receive the ADC output signal and output a filter signal; and

a comparator circuit configured to generate the first protection signal based on comparing the filter signal with a predefined threshold.

7. The electronic circuit of claim 6,

wherein the ADC is a logarithmic ADC configured to generate the ADC output signal such that the values of the sequence of values represents a logarithm of a respective sample of the ADC input signal.

8. The electronic circuit of claim 6,

wherein the control circuit being configured to output a signal level representing a level of the current through the load path comprises the control circuit being configured to output the ADC output signal.

9. The electronic circuit of claim 1,

wherein the control circuit further comprises an input configured to receive an input signal, and

wherein the control circuit is configured to drive the electronic switch based on the input signal in both the first operation mode and the second operation mode.

10. The electronic circuit of claim 1, wherein the control circuit is configured to generate the first protection signal in the first operation mode and not in the second operation mode.

11. The electronic circuit of claim 1, further comprising:

a current measurement circuit configured to measure the load current and provide a current measurement signal proportional to the load current,

wherein the control circuit being configured to operate the electronic circuit in a first operation mode or a second operation mode based on the load current comprises the control circuit being configured to operate the electronic circuit in the first operation mode or the second operation mode based on the current measurement signal.

12. The electronic circuit of claim 11,

wherein the control circuit comprises an ADC configured to provide an ADC output signal based on the current measurement signal, and

wherein the control circuit being configured to operate in the first operation mode or the second operation mode based on the current measurement signal comprises the control circuit being configured to operate in the first operation mode or the second operation mode based on the ADC output signal.

13. The electronic circuit of claim 11, wherein the control circuit is configured to adjust a proportionality factor between the load current and the current measurement signal to have a first value in the first operation mode and a second value lower than the first value in the second operation mode.

14. A method, comprising:

generating a first protection signal based on a current-time-characteristic of a load current through a load path of an electronic switch in an electronic circuit;

operating the electronic circuit in one of a first operation mode and a second operation mode at least based on a level of the load current; and

generating a status signal such that the status signal, when operation changes from the second operation mode to the first operation mode, has a wakeup pulse and, after the wakeup pulse, a signal level representing a level of the load current.

15. The method of claim 14, wherein generating the status signal in the first operation mode comprises continuously outputting the signal level representing the level of the load current.

16. The method of claim 14, wherein generating the status signal in the first operation mode comprises:

receiving a polling signal by the electronic circuit; and

outputting the signal level representing the level of the load current only upon request by the polling signal.

17. The method of claim 16, further comprising:

in the second operation mode, outputting a status pulse different from the wakeup pulse upon request by the polling signal.

18. The method of claim 15, wherein operating the electronic circuit in one of the first operation mode and the second operation mode at least based on the level of the load current comprises:

changing operation from the second operation mode to the first operation mode when the load current reaches a predefined threshold.

19. The method of claim 14, further comprising:

receiving an input signal by the electronic circuit, and

driving the electronic switch based on the input signal in both the first operation mode and the second operation mode.

20. The method of claim 14, further comprising:

generating the first protection signal in the first operation mode and not in the second operation mode.

21. The method of claim 14, further comprising:

measuring the load current and providing a current measurement signal proportional to the load current,

wherein operating the electronic circuit in the first operation mode or the second operation mode based on the load current comprises operating the electronic circuit in the first operation mode or the second operation mode based on the current measurement signal.

22. The method of claim 21,

wherein a proportionality factor between the load current and the current measurement signal has a first value in the first operation mode and a second value lower than the first value in the second operation mode.