LP8860 I_SLOPE

Masatoshi Oguri

Hello,

What do the register bits I_SLOPE[2:0], or slope gain, represent?

What difference is there between slope gain being 1.000 and 1.164?

For me it looks like there must be no number other than 1. When the brightness is 100% the current must be 100%, while when the brightness is 50% the current must be 50%. Hence slope gain cannot be other than 1.000. Am I wrong?

Thanks.

Oguri (TI FAE)

over 10 years ago

0 Tomi Koskela over 10 years ago

TI__Genius 11020 points

Hi Oguri-san,

Slope can be used to compensate for the brightness non-linearity presented to LEDs when adjusting brightness with current dimming. For example with 1.164 slope the actual current at 50% brightness is less than 50%. Slope can be adjusted based on LED type and maximum current used.

Thanks.

0 V.Trondin over 10 years ago in reply to Tomi Koskela

TI__Prodigy 460 points

Here is illustration for different slopes:

Power management

Power management forum

LP8860 I_SLOPE