PCA9956B color drift in temperature?

[Tosselino]

Hi,

I am using a PCA9956B to control some RGB-LEDs. In room temperature they are set to emit a green light. When we then test the unit in -40C the light is more orange. We have used the same LEDs with different driver before and not seen this. What can cause this and how to avoid color drift?

[JozefKozon]

Hi Torbjoern,

please share your schematic with voltage levels and part values. 

Please share the LEDs datasheet you are using.

Please confirm. Do you mean that with the same LEDs, but with different LED driver the LED didn't change color with same configuration and at ambient temperature of 25 C and -40 C? But the color changes with the PCA9956B.

Please share your registers settings. 

Could you please share pictures of the LEDs for both color cases? (Green and Orange)

With Best Regards,

Jozef

[Tosselino]

Thanks for your quick reply. At the moment I think this is related to the diodes, I will do some testing in the lab. Then I update the info here if needed. Thanks

[JozefKozon]

Hi Torbjoern,

ok. Thank you for confirmation. 

With Best Regards,

Jozef