TPA6211A1-Q1 Over Current Protection

Hello,

 

Please answer my previous question.

 

Also, please advise how many current will flow from VDD to VO when output is shorted to GND.

 

Best Regards.

I answered a similar question for you several months ago:

e2e.ti.com/.../489156

And this post has current measurements during a short to ground condition:

e2e.ti.com/.../480904

Hello Clancy-san,

Thank you for your answer.

I’m sorry I forgot I have ever asked same question.

 

Your answer and link said that thermal shutdown will work when VO is shorted.

 

I tested the shutdown behavior using TPA6211A1 EVM and result is attached.

When I shorted VO- to GND, VO repeat high and 0V and it looks like repeating shutdown and wakeup.

When I sorted VO+ to VO-, VO repeat high and 0V and it looks like repeating shutdown and wakeup.

I also measured VDD current using current meter of DC power supply.

TPA6211A1-Q1 VO short to GND.pptx

 

 

Please advise is this working thermal shutdown.

Does TPA6211A1-Q1 continue shutdown while Tj is higher than 150C?

 

Best Regards.

That is correct, the thermal shutdown will turn off the outputs, but once the device cools down, it will turn back on. If this repeated on/off behavior is a problem, then it is advisable to have an external diagnostic circuit so that the shutdown pin can be pulled low during a short circuit condition.

Hello Clancy-san,

Thank you for your answer.

I tested thermal protection by short VO+ and VO- to GND during 10 to 15 minutes.

After above short test device was damaged.

VO+ output normal sign wave but VO- output 0V with no speaker.

VO+ and VO- output same phase sign wave with speaker, so I think VO- is floating.

Could you confirm that VO short to GND doesn’t damage the device because thermal protection protect the device.

Best Regards.

How were you testing this?

- Was there a load?
- Was there an input signal?
- What was the VDD voltage?

When I tested it with a load, the thermal shutdown kicked in, and the measured current would decrease slightly. Note that the device will automatically attempt to recover, meaning that in a constant short situation, it will continue trying to turn on.

Thanks,

-Clancy

Hello Clancy-san,

 

Thank you for your test.

 

I tested as following.

 - Was there a load? ⇒6 ohm speaker

  - Was there an input signal? ⇒apply 3Vp-p 1KHz sign wave to IN- of EVM, IN+ is connect to GND, so output is 6Vp-p differential.

  - What was the VDD voltage? ⇒5V

 

I tested following short case.

Case-1: VO+ or VO- to GND

Case-2: VO+ and VO- to GND at the same time.

 

I continued to short during 5 minute and VDD current is decreased around 1.1A to 0.6A but it did not decrease significantly for Case-1 and Case-2.

 

Q1:

Does “Some mArms” of José-san’s answer means 3 or 4 mA?

 

Q2:

I don’t have another EVM to test short to GND.

Could you confirm that device is not damaged after your short test?

 

Best Regards.

Q1: I'm not sure what Jose was referring to, but I saw the current drop several hundereds of mA. This is because it was going into thermal shutdown, so the average current would decrease.

Q2: My EVM was not damaged during short to ground, but it would be a good idea to figure out why yours was damaged. I will run a few more tests to see if I can damage my EVM with various short circuit conditions.

Thanks,

-Clancy

Hello Clancy-san,

 

Thank you for your EVM short current information and test results.

 

Please let me known your few more test results.

 

Best Regards.