LP5861: Dynamically controlling individual LEDs

Tyler Holmvik

Part Number: LP5861

Hi -

For LP5861 18-Channel LED Driver, it has MC settings, CC (Group Current) setting, and DC (Dot Current).

Can LP5861 handle dynamic modification to DC (Dot current settings) for individual LED? Are there any drawback to changing these parameters dynamically instead of at startup?

Tyler

6 months ago

0 Jared Zhou 6 months ago

TI__Genius 14215 points

Hi Tyler,

When you talk about the dynamic modification to DC, do you mean that you want to LED driver modify the DC by itself without MCU when running or you want to the device load the value by itself at startup?

BR, Jared

0 Tyler Holmvik 6 months ago in reply to Jared Zhou

TI__Prodigy 611 points

From customer:

Currently we have code to initialize LP5861’s MC/CC/DC Current settings and we only do it once. Then in a very tight loop, the code turn off/on LEDs.

My question is: is there any drawback to keep updating the “DC (Dot current setting register)” for each LED in this continuous loop?

Tyler

0 Jared Zhou 6 months ago in reply to Tyler Holmvik

TI__Genius 14215 points

Hi Tyler,

Could you please tell me how long this tight loop lasts and what's the communication rate?

BR, Jared

0 Tyler Holmvik 6 months ago in reply to Jared Zhou

TI__Prodigy 611 points

Currently our fastest testing scenario is 25ms but we could also go down to 1ms.

Setup is 5 Mhz, SPI.

Tyler

0 Jared Zhou 6 months ago in reply to Tyler Holmvik

TI__Genius 14215 points

Hi Tyler,

I think it would be no problem to keep update DC in the continuous loop.

BR, Jared

Power management

Power management forum

LP5861: Dynamically controlling individual LEDs