TLC5922: Thermal Resistance theta(j-a), Theta(j-c) and psi(j-b) and psi(j-c)

Hi Shinichi,

Considering this device is quite old material, so we cannot find the information you need.

But I'd like to recommend you our new device LP5861/LP5018, which are 18 channels LED drivers.

Thanks!

Hi Ives,

I had an experienced person in the company calculate the thermal resistance value (θj-a).

Could you please confirm?

According to the TLC5922 datasheet, page 2
Continuous total power dissipation at (or below) TA = 25°C 3.9W
Power dissipation rating at (or above) TA = 25°C 31.4mW/°C
are described.

3.9W/(31.4mW/°C) = 124.2°C, so
Tj(Max) is numerically assumed to be 124.2°C + 25°C = 149.2°C and about 150°C.
Continuous total power dissipation at (or below) TA = 3.9W at 25°C
Since the allowable temperature rise is 125°C,  θj-a should be  125°C/3.9W ≒ 32°C/W.
(After all, it is the same as the reciprocal of 31.4mW/°C multiplied by 1000.)

I appreciate your great help and cooperation.

Best regards,

Shinichi

Hi Shinichi,

For thermal resistance, you can take below guidance as reference:

Semiconductor and IC Package Thermal Metrics (Rev. C) (ti.com)

Thanks!

HI Ives,

Thank you for sharing. 

Shinichi