LP8863-Q1: Vboost Adaptive Control of LED0 to LED5

Ting Ye

Part Number: LP8863-Q1

Since comparator circuit will be connected to LED0 to LED5 pins, a threshold needs to be decided.

May I know if there is equation containing Vboost, LED max forward voltage, and LED # etc., to calculate the LED0 pin high and low voltage level so that we can use the equation to set a comapartor threshold?

Thank you.

Regards,

Ting

over 7 years ago

0 Shirley He over 7 years ago

TI__Expert 5475 points

Hi Ting,

Since LED forward-voltage mismatch may be high, we cannot get the high and low voltage level on LEDn pins.
For the low level voltage, we can only say that at least one channel output is between LED_DRV_HEADROOM and LED_DRV_HEADROOM+500mV. The other channel LEDn voltage may between this range, or may even be higher than LED_DRV_HEADROOM+500mV.
For the high level voltage, it's related to the Characteristics of the LED. It's also not easy to have any equation of this.