DLP4710EVM-LC: RGB LED Minimum Current

Keisuke Goto

Intellectual 600 points

Part Number: DLP4710EVM-LC
Other Parts Discussed in Thread: DLPC-API, DLPC3479

I have a question about DLP4710EVM-LC LED minimum current.

I set the LED current setting value 50 at 10bit resolution, using DLPC-API Command "DLPC34XX_DUAL_WriteRgbLedCurrent".

Then I read the current using "DLPC34XX_DUAL_ReadRgbLedCurrent", the return value is "91".

Does this because DLPC3479 F/W limit the minimum current setting value?

And Could you get rid of this limit ?

over 5 years ago

0 Philippe Dollo over 5 years ago

TI__Mastermind 28005 points

Keisuke,

You are correct, there is a minimum limit on the DAC output for the LED in this case (91/1023).

These limits are set in place due to the LEDs having poor linearity when operating at minimum DAC values. Running the system below the specified levels can cause noticeable color nonlinearity in image output.

What are you trying to do that would require you to run at the minimum DAC output setting?

Regards,

Philippe Dollo

0 Keisuke Goto over 4 years ago in reply to Philippe Dollo

Intellectual 600 points

Philoppe san,

Thank you for your response.

I understood the limimt value of "91" is because of LED linearity,.

I was thinking of using an EVM to drive an LED with a small current capacity, so I asked a question.

Regards,

Goto

0 Mayank Khandelwal over 4 years ago in reply to Keisuke Goto

TI__Genius 9971 points

Goto-san,

Thanks for your confirmation.

Regards,

Mayank

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DLP4710EVM-LC: RGB LED Minimum Current