TPS65381A-Q1: About the open time and close time

whong zhao

Part Number: TPS65381A-Q1
Other Parts Discussed in Thread: TPS65381-Q1

Hello

Team

I found the paper of TPS65381A ,dont have the open time and close time calculation way.only have the max and min time. in 5.4.12

and the paper of TPS65381, have the open time and close time calculation way. They are very different

please tell the TPS65381A calculation way.I hope to see evidence

Thank you

over 4 years ago

0 Layne J over 4 years ago

TI__Genius 12735 points

Hi Whong,

Can you clarify what open and close time you are requesting? Do you mean the watchdog window timing or are you asking about start up time? Can you point me to the paper you are talking about?

Best regards,

Layne J

0 whong zhao over 4 years ago in reply to Layne J

Genius 4180 points

Hello

watchdoge window in the TPS65381 paper in the 5.4.1.14.2 ,but in paper of the TPS65381Q，I dont find about if ，only have the max and min

0 Layne J over 4 years ago in reply to whong zhao

TI__Genius 12735 points

Hi Whong,

The information in the datasheet for TPS65381A-Q1 is the correct information regarding Watchdog timing. I am not sure what paper you are referring to, if you can tell me what other paper you are looking at I can look at why there is a discrepancy.

Best regards,

Layne J

0 whong zhao over 4 years ago in reply to Layne J

Genius 4180 points

Hello

the paper of TPS65381A dont have the watchdog time calculate way.How to calculate

0 Layne J over 4 years ago in reply to whong zhao

TI__Genius 12735 points

Hi Whong,

The formulas found in section 5.4.12 of the datasheet are the only formulas we have to calculate the watchdog. I am not sure where the confusion is, can you please explain why you feel these formulas are incorrect?

Best regards,

Layne J

0 whong zhao over 4 years ago in reply to Layne J

Genius 4180 points

that only give the min and max time，dont give the nomarl calculate time

0 Layne J over 4 years ago in reply to whong zhao

TI__Genius 12735 points

Hi Whong,

That is correct. When calculating the watchdog windows the only values that are important are the minimum and maximum window sizes. The maximum formula is used to calculate the maximum possible window length based on the value of RT or RW. The internal clock used for the watchdog is ±5% accuracy, which can lead to some uncertainty in the Window 1 and Window 2 time periods. This is why we provide the minimum and maximum equations, so the user can know what the maximum possible timeout time is and what the minimum possible timeout time is.

Best regards,

Layne J

0 whong zhao over 4 years ago in reply to Layne J

Genius 4180 points

Hello

I Means ,the TPS65381 paper have the calculate is

but the TPS65381Q paer dont have the calculate

0 Layne J over 4 years ago in reply to whong zhao

TI__Genius 12735 points

Hi Whong,

Where are these screenshots from? That is not a section found in the datasheet for TPS65381A-Q1. Please clarify where you are finding this information so I can try to explain the difference.

Best regards,

Layne J

0 whong zhao over 4 years ago in reply to Layne J

Genius 4180 points

Hello

It must be downloaded from TI's official website. I found in the datasheet for TPS65381-Q1,so that’s why I asked why they are different

What do you mean? Is this wrong? There is no specific calculation, only the maximum and minimum.

0 Layne J over 4 years ago in reply to whong zhao

TI__Genius 12735 points

Hi Whong,

You are currently using an out of date datasheet. I would recommend using the latest version of the datasheet currently found on the web: https://www.ti.com/lit/ds/symlink/tps65381a-q1.pdf

Best regards,

Layne J

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TPS65381A-Q1: About the open time and close time