Hi,
I got a inquiry about Power dissipation(Pd).
I can find RθJA graph in the datasheet. But customer wanted to get a graph about power dissipation(Ambient temperature vs Pd, Pd according to package).
If you have any information about Pd, could you give me some information about it?
Thank you.
Best Regards,
Kevin Shin
Hi Kevin,
Soon we will have a thermal widget come online which will allow you to estimated thermal performance based on package and temperature. For now the best way to estimate this is with RθJA.
This is used as follows: TJ=TA+PD*RθJA Where:
TJ is the junction temperature
TA is the application Ambient temperature
P is the Power Dissipated (PD=(VIN-VOUT)*ILOAD)
and is from the below table:
Do this answer your question?
Hi John,
Thank you for your detail explanation.
I understood changes of RθJA, TJ according to package.
By any chance, is there any table or information about Pd like the below graph that customer wanted to see?
Thank you.
Best Regards,
Kevin Shin
Hi Kevin,
I put together this simple spreadsheet to help predict maximum power dissipation:
This should apply to any LDO.
Does this work for you?
Hi Kevin,
TJA is RθJA. I updated the spreadsheet to be clearer:
Does this help to clarify?
Hi John,
I have one more question about power dissipation.
Can TPS745-Q1 withstand power dissipation in the environment of that graph?
And also can this device guarantee all of robust environment like below graph?
Thank you for your support in advance.
Best Regards,
Kevin Shin
