LP8863-Q1: LED Driver and LP8863 general question

Hi William,

A) The dither function is used to increase resolution and brightness step. What is the difference between 12 bit dimming resolution and 11 bit dimming resolution + 1 bit dither?

When the 1-bit dither is selected, the width of every second PWM pulse is increased by one LSB. The average effect of 11 bit dimming resolution + 1 bit dither is equal to 12 bit dimming resolution.

B)

Does LP8863 have EEPROM? Yes.

I could see the EEPROM block in the datasheet block diagram, but I cannot find the EEPROM setting like LP8860.

You can't revise therm.

C)

This is very basic, but I could not find the answer.

Could you tell me the meaning of dimming ratio exactly?

And the different between 32000:1 and 10000:1.

I suggest that you can refer to the training video in my signature. The additional information in the training materials will be helpful to you.

D)

I could see the 1% current matching on the datasheet.

What is the meaning of current matching?

Output Current Accuracy is the difference between the actual value of the output current and programmed value of this current.
Matching is the maximum difference from the average.

Hi William,

A) The dither function is used to increase resolution and brightness step. What is the difference between 12 bit dimming resolution and 11 bit dimming resolution + 1 bit dither?

When the 1-bit dither is selected, the width of every second PWM pulse is increased by one LSB. The average effect of 11 bit dimming resolution + 1 bit dither is equal to 12 bit dimming resolution.

> Are those exactly same(brightness, color)? so, We do not need to use dither under 12 bit dimming resolution, because we can control with dimming resolution, correct?

The average brightness is almost the same.

B)

Does LP8863 have EEPROM? Yes.

I could see the EEPROM block in the datasheet block diagram, but I cannot find the EEPROM setting like LP8860.

You can't revise therm.

> I cannot change the setting, but I can save the LED pattern in the EEPROM, is this understanding correct?

Sorry, the EEPOM value is set by default and can not be revised for user.

C)

This is very basic, but I could not find the answer.

Could you tell me the meaning of dimming ratio exactly?

And the different between 32000:1 and 10000:1.

I suggest that you can refer to the training video in my signature. The additional information in the training materials will be helpful to you.

> Thank you for the suggestion, I already saw everything, but I could not find about the dimming ratio, this is why I ask you. I would be happy if you explain about this a little bit.

You can refer to the following threads.

e2e.ti.com/.../808858

D)

I could see the 1% current matching on the datasheet.

What is the meaning of current matching?

Output Current Accuracy is the difference between the actual value of the output current and programmed value of this current.
Matching is the maximum difference from the average.

> Could you explain how the current difference occurs?

Many aspects will lead to difference, for example, the slight characteristic difference of output mosfet and so on.