TPS25983: Inquiry about the TPS259830ONRGE (Circuit breaker)

Hi JH,

No, the device should be able to return back to normal operation if the load is again back to normal value (within ILIM). Can you share some more details regarding the experiment they are performing.

Details like load value, overload value, any waveform, it is recovering after some retires or not recovering at all.

Best Regards,
Arush

Dear ARUSH Gupta

Hi , im seonyeong.

Thank for your response.

That question was asked by me

I'm currently testing with the TPS25983 EVB, which has been replaced with a Circuit Breaker IC, under the condition of a 12V input with a current limit of 20A. I've confirmed that when applying a load of over 20A to Vout, the Vout's cutoff occurs, triggering nRETRY. nRetry is set to infinite with a 1-second interval. The testing environment involves supplying power to the EVB via a power supply and using a loader for the load.

1. Could the reason for the EVB not recovering during nRETRY when my Vout drops be simply attributed to testing with a loader, even though in actual product configuration there is no load? (I expect it to operate when the load drops from 21A to 19A.)
2. When the load is increased beyond the limited current, the IC is stated to release current without restrictions until it momentarily cuts off. What is the breakpoint in this case? Will there be no damage even at around 30A?
3. Can we consider the fundamental difference between Circuit Breaker and Current Limit to be merely the method of interruption, from the first overcurrent occurrence to latch-off?
4. I intend to use a terminal box FAN at the rear of this product. Is this product suitable for such a solution? Or do you recommend a similar part with matching specs? If so, please provide recommendations.

Thank you.

Hi Kim,

Can you confirm the e-load's mode you are using. If you are using CC mode, can you quickly try this experiment with CR mode. In Overcurrent protection, eFuse with CC mode of e-load can result in unexpected waveforms as both are current sources and connected in series. 

Regarding your questions,

1. As previously mentioned, the device should recover. I see that in your experiment. going from 21A to 19A, the device is not recovering. Can you tell me when it is recovering. Are you forced to turn off the e-load completely or just to some lesser load like 10A or 5A.
2. Any waveform? Is the current going beyond the applied load also? (Is it a transient or steady state current higher than current limit
3. CB device will stop output when the current limit is crossed. CL device will limit the current to ILIM and because this will cause excess power to dissipate at device, device will turn off eventually due to Thermal shutdown to keep itself safe.
4. I am assuming that you selected this device based on your requirements. Yes, the device is suitable for the application. You can also evaluate this using the EVB and connect the desired load. 

Best Regards,
Arush

thank you for your response.

1.It only works if I turn off the e-load and completely remove the current.

2.If i set it to 24A in e-load, it outputs as if 24A is being used in the power supply. There is no actual measured waveform.

Thank you for helping me.

Hi Kim,

Can you confirm the e-load mode. Is it CC mode or CR mode? Also, can you redo the experiment with CR mode if CC mode was used previously. 

Best Regards,
Arush

Hi ARUSH,

I confirmed that the loader mode is CC. I will test it with CR.

I will reply again after confirmation.

Than you

Hi Kim,

Sure, we will discuss after you get new results.

Thank you,
Arush

HI ARUSH,

Upon checking, it appears that the loader is wrong working.

So I tested using Fan instead of Loader.

This fan normally operates at about 5A and increases to 8A when starting.

So it often fails to work and retry is repeated.

If i wait a little while, it may restart again and then start working.

(Circuit breaker/ infinite mode / limit 5A, 12V working)

I want to operate a Fan with 8A peak starting current stably even under 5A limiting conditions.

In this case, is there any way to overcome this other than raising the limit current?

Thank you.

Hi Kim,

Before discussing the new issue. I want to confirm, were you able to resolve your previous issue?

Regarding new issue, do you want a blanking timer i.e. some time delay during which overcurrent fault can persist.

If yes, you can use itimer pin to add some blanking time.

If no, can you please describe the issue again.

Best Regards,
Arush

HI ARUSH

Thank you for your answer.

i resolve my previous issue.

i think that i can solve my problem with your answer(using blanking timer)

Thank you

and i have a question onemore

now my EVB itimer capacitor => 4.7uF

Is there any problem with this setting?

is there maximum(limited) time?

Hi Arush,

Could you please reply the above customer's additional questions?

Thanks,

JH

It did not attach the image which I tried sharing above.