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Associate II
April 24, 2025
Solved

Juction Temp L6235Q

  • April 24, 2025
  • 3 replies
  • 378 views

Hi the datasheet does not contain the thermal junction temperatures for the VFQFPN48, hence hard to work out the max thermal temps for the device. please can you supply

regards

Ross

Best answer by Peter BENSCH

I see... the thermal resistance is missing.

I don't have any data available like for the L6235, but you can probably assume an Rth(ja) of 25...50K/W, depending on whether you connect the NC pins to the cooling GND surface, use thermal vias and what type of board you use. Much more important, however, is probably Rth(j-case), which will probably be around 1.5K/W.

However, you are welcome to create a ticket with the personal Online Support OLS and request exact thermal resistance values.

Hope that helps?

Regards
/Peter

3 replies

Peter BENSCH
Technical Moderator
April 24, 2025

The data sheet, table 2 mentiones for the operating junction temperature Tj a range of -25...125°C.

Does it answer your question?

Regards
/Peter

Associate II
April 24, 2025

Hi Peter , no as the standard L6235 has a table that you can work out the IC temp for a given PCB layout. see below. without this you can not work out the IC temp. I have worked out the IC power but need this to make sure I can apply the brake without blowing the IC 

cheers

Ross

ross_atkinson_0-1745494377577.png

 

Peter BENSCH
Peter BENSCHBest answer
Technical Moderator
April 24, 2025

I see... the thermal resistance is missing.

I don't have any data available like for the L6235, but you can probably assume an Rth(ja) of 25...50K/W, depending on whether you connect the NC pins to the cooling GND surface, use thermal vias and what type of board you use. Much more important, however, is probably Rth(j-case), which will probably be around 1.5K/W.

However, you are welcome to create a ticket with the personal Online Support OLS and request exact thermal resistance values.

Hope that helps?

Regards
/Peter