LP8864S-Q1: PWM dimming vs I2C dimming

Yuta Kurimoto

Part Number: LP8864S-Q1

Hello Team,

Our customer is considering to use LP8864S-Q1.

They understood this device can select either option PWM dimming or I2C dimming. They are wondering which method should they use.

Q. Can you let me know each pros/cons about PWM dimming vs I2C dimming?

Thanks,

Yuta Kurimoto

0 Yuta Kurimoto over 4 years ago

Hello Team,

Do you have a chance to look my question and provide answer?

Thanks,

Yuta Kurimoto

0 Charles-Chen over 4 years ago in reply to Yuta Kurimoto

Hi Kurimoto-san,

PWM dimming don't have delay but will has some jitter.

I2C dimming has delay but it accurate.

0 Yuta Kurimoto over 4 years ago in reply to Charles-Chen

Hello Chen,

Thanks for your answer. Let me clarify about this.

From the datasheet figure.7-9, the only difference of path diagram between PWM dimming and I2C dimming is first block(circled by blue).

Q. I2C dimming need to load the DISP_BRT register so it has longer delay, correct?

Q. I'm not sure the circuit of the PWM detector. but why does it have more jitter?

+1 Charles-Chen over 4 years ago in reply to Yuta Kurimoto

Hi Kurimoto-san,

I2C dimming need some time to communicate so it has some delay.

PWM is generated by the front MCU that may has some jitter or affected by the noise in the process of transmission.

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