TPS56339: Vstop電圧

Hi Yuki

Can you please post the question using English?

Thanks and best regards.

Hi Gui

Please check the translation into English.

We have calculated the EN pin for model TPS56339 as shown in the attached Excel file and set the Vstop voltage to 10.245V. However, when the input voltage to the IC temporarily dropped below the set Vstop of 10.245V, the output did not stop. We investigated the above and found that the output stops when VIN drops below 10.25V for 0.2ms, and does not stop when the time is less than 0.2ms. If you have any information on the minimum time that Vstop is below the set voltage as a condition for stopping the output, please let us know.

Hi Yuki

The EN UVLO monitor the EN voltage and when EN fall below 1.12V, the IC disables. Did customer monitor the EN voltage close to the IC EN pin? 

Thanks and best regards.

Hi Gui

The EN voltage also behaved in the same way as VIN, not stopping output when it fell below 1.12V for 0.175ms, but stopping when it fell below 0.2ms.

Hi Yuki

Please let me check about this and get back to you later.

Thanks and best regards.

Hi Yuki

There is some delay between EN fall below the threshold and the IC disables. The 0.2ms is normal range. There should be no problem here.

Thanks and best regards.

Hi Gui

Let me ask an additional question.

How long is the delay between EN falling below the threshold and the IC being disabled?
Specifically, how many ms or less after EN falls below the threshold does the IC continue to output without being disabled?

Hi Yuki

There is no specific data as this is caused by the inner circuit delay(like the comparator) and the capacitor between EN and GND. 

BR.

Hi Gui

I would like to know if there is any experimental data regarding this phenomenon that can be used as a reference.

Hi Yuki

I don't have the TPS56339 evm on hand now, I have requested for evm sample and I can test when it arrives. Besides this, customer measured Vin and calculated the EN , can customer directly measure on EN pin? That should be more accurate.

thanks and best regards.

Hi Gui

We would love to have you test our products as it will take time to build an environment to test them.

Hi Yuki

thank you, will keep you updated.

thanks and best regards.