LP8860-Q1: DRV_EN_SPLIT_FET (0x66[2])

Kuramochi Tadahiko

Guru 28715 points

Part Number: LP8860-Q1

Hi,

I don't know how we should choose ON/OFF of the register DRV_EN_SPLIT_FET (0x66[2]).

Is there any reference of "big size FET"?

This question is related to the following thread.

Best Regards,

Kuramochi

over 8 years ago

0 Scott Monroe over 8 years ago

TI__Mastermind 20590 points

Hi Kuramochi,

I'm going to move this thread from the automotive forum into the LED forum. This device is supported by the LED team and they should be able to answer it better from the LED forum.

Best Regards,
Scott

0 Sung Ho Yoon over 8 years ago

TI__Expert 4565 points

Small FET can be selected when the resolution and accuracy at low brightness(<1/16 brightness level) are critical.

And using big FET may cause some noise or fluctuation at very low brightness level.

This is the E2E link you've asked before.

LP8860 / Brightness fluctuation

One downside of small FET is there may be a slight step at transition point between small and big FET which can be acceptable for most of the cases.

0 Kuramochi Tadahiko over 8 years ago in reply to Sung Ho Yoon

Guru 28715 points

Sung-san,

Thank you for your answer.

I have an additional question.

The datasheet says that " Automatic scaling improves accuracy for output

currents below 1/16 of the full current scale."

Does the full current scale mean the set value by DRV_LED_CURRENT_SCALE[2:0]?

Best Regards,

Kuramochi

0 Sung Ho Yoon over 8 years ago in reply to Kuramochi Tadahiko

TI__Expert 4565 points

Answered by email

Power management

Power management forum

LP8860-Q1: DRV_EN_SPLIT_FET (0x66[2])