DLP3010EVM-LC:Regarding the change of the DLP's transient current limit.

YONGJIN LEE

Prodigy 70 points

Part Number: DLP3010EVM-LC
Other Parts Discussed in Thread: DLPA2005, DLPC3478

Hello, I'm yongjin.

I am working on a project by configuring DLPC3478, DLPA2005 and DMD3010.

I want to fix the problem that when the DLP RGB LED turns on, the current rises momentarily and then stabilizes.

Looking at the datasheet, there is a transient current limiting function, but I don't know how to use it.

In the meantime, I checked the forum and confirmed that TI directly modified and sent the FW.

I also want to receive the modified FW. I want to set the transient current limit of the RGB LED to 2550mA.

Reply please. thank you.

over 1 year ago

0 John McKnight over 1 year ago

TI__Expert 5310 points

Hello User,

Are you seeing this rise in the LED current for every LED or particular one? It is to be expected that there is some inrush when switching LEDs.

Do you have a screenshot of the LED current to give more context?

Can you provide the thread that you mentioned?

Regards,

John

0 YONGJIN LEE over 1 year ago in reply to John McKnight

Prodigy 70 points

hello. Thank you for answer.

I have attached the requested screenshot below.

And the phenomenon occurs with all LEDs.

please answer about my question.

0 Austin Snyder over 1 year ago in reply to YONGJIN LEE

TI__Genius 12595 points

Hello User,

Is it possible to have a link to the thread that you mention regarding the modified firmware? We would like to be sure of how this was implemented previously.

Regards,

Austin

0 YONGJIN LEE over 1 year ago in reply to Austin Snyder

Prodigy 70 points

hello.

Thank you for answer.

The link I referenced is below.

e2e.ti.com/.../dlp3010evm-lc-about-current-limit-control

please answer about my question.

0 John McKnight over 1 year ago in reply to YONGJIN LEE

TI__Expert 5310 points

Hello User,

Allow us some time to review the mentioned thread.

Regards,

John

0 John McKnight over 1 year ago in reply to YONGJIN LEE

TI__Expert 5310 points

Hello User,

The change that you requested will not affect the behavior that you are currently seeing. This is just the inrush current from LEDs switching on and off.

The peak current is higher than expected. Have there been any changes to the EVM?

Regards,

John

0 YONGJIN LEE over 1 year ago in reply to John McKnight

Prodigy 70 points

hello.

I don't use EVM.

I made a custom board using DLPC3478+DLPA2005.

The circuit between DLPA <-> LED is directly connected in the same way as the EVM circuit.

The LEDs we use are KP CSLNM1.F1_EN, KB CSLNM1.14_EN, KR CSLNM1.23_EN.

And looking at the waveform, the current required for the basic operation of the custom board is about 1.2A. Other than that part, I don't think the LED current is high. (Excluding that part, I think the LED peak current will be about 3.7A.)

That's why I asked you about how to limit the transient current.

For further questions,

1. I want to test it, but I can't change the transient current limit?
2. If you think point 1 doesn't work for you, can you suggest a way to reduce the inrush current?

Please answer two questions.

thank you

0 Austin Snyder over 1 year ago in reply to YONGJIN LEE

TI__Genius 12595 points

Hi User,

Would it be possible to see the illumination circuitry for the LEDs on your board? This would be the equivalent for this area:

Also, what is the key care about for this request? I ask because we will likely not be able to completely eliminate the overshoot, but we may be able to accommodate your needs by another method.

Regards,
Austin

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DLP3010EVM-LC:Regarding the change of the DLP's transient current limit.