SN74CB3Q3245: SN74CB3Q3245RGYR hermal resistance

Alan Chang

Intellectual 2160 points

Part Number: SN74CB3Q3245

Hi there,

can you please provide below data to my customers?

Q1:θjc=?
Q2:Max withstanding operating junction temperature spec Tj=?

over 2 years ago

0 Tyler McGuire over 2 years ago

TI__Expert 3515 points

Hi Alan,

We have a recently released an FAQ on this topic, the content is applicable for all of our switches.

The link is here: https://e2e.ti.com/support/switches-multiplexers-group/switches-multiplexers/f/switches-multiplexers-forum/1063078/faq-how-to-calculate-the-max-junction-temperature-of-an-analog-switch-multiplexer

It includes a calculator to help calculate the max temperature as we typically don't provide max junction temperature as a spec for analog switches and multiplexers, because the large majority of the analog switch and multiplexer portfolio at TI (the SN74CB3Q3245 included) will never reach a junction temperature that is dangerous for the part if the datasheet is followed. However you can estimate the max temperature it will reach during operation - the FAQ I linked explains how it is done as well as providing an excel tool to help calculate so it doesn't have to be done manually.

If you have any other questions please let me know!

Thanks,

Tyler

0 Alan Chang over 2 years ago

TI__Intellectual 2160 points

Hi Tyler,

Thanks for your update, but I still need :θjc=?

0 Tyler McGuire over 2 years ago in reply to Alan Chang

TI__Expert 3515 points

Hi Alan,

Unfortunately we don't have this information on file but I'm putting in a request now for you and will update you as soon as possible. Typically this process can take up to 2 weeks.

Thanks,

Tyler

0 Alan Chang over 2 years ago in reply to Tyler McGuire

TI__Intellectual 2160 points

Hi McGuire,

Q2:Max withstanding operating junction temperature spec Tj=?

what customer needs is max.. junction temperature? saying 125 or 150C, not max. power consumption. Can you please support max. junction temp.?

0 Clemens Ladisch over 2 years ago in reply to Alan Chang

Guru 268300 points

150 °C; see [FAQ] What is the maximum junction temperature (TJMAX) for a device?

0 Tyler McGuire over 2 years ago in reply to Alan Chang

TI__Expert 3515 points

Hi Alan,

The excel tool from the FAQ can help calculate the max junction temperature. You have to input various max spec parameters that are listed on the datasheet and the table will automatically estimate Tj.

I went ahead and filled it out for this device and Tj was calculated at 111.6 °C