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DLPA2005 : External Cthode method of LED.

Part Number: DLPA2005
Other Parts Discussed in Thread: DLPC3478

DLPA2005 is operated in the R, G, B of an LED are sequentially.

(Chipset : DLPC3478)

  • Hello ,

    Welcome to TI E2E forums and thanks for showing interest in DLP technology.

    Unfortunately, the DLPC3478 chipset is capable of only sequential LED support. Hence it will not be possible to meet a condition where multiple LEDs are operated simultaneously.



  • Dear Mayank,

    I know that the DLPC3478 works sequentially.
    So, I want to implement it as mentioned above.
    It is to ask if there is any precaution.
    Or, have other companies considered the same method as mine?



  • Seong,

    Please refer to my comments below -

    It sounds like you would like to operate G&B and R&B simultaneously.  Based on the LED select lines the DLPA2005 drives the R, G, and B LED.  If you want to drive G and R at the same time then they will have to be connected to the same low side FET inhe DLPA2005.

    So option 1 wouldn’t give you the expected outcome. Also while connecting different LEDs with different VLED voltages to the same channel you won’t get the same current through both LEDs so the light output will be different.

    Option2: I assume the cathode is not connected to the DLPA2005 anymore. The DLPA2005 will stop driving VLED since there is no feedback anymore.

    Option 3:  Would work. Customers can use external LED drivers in combination with our PMICs to drive additional LEDs at the same time with our sequential LEDs. We don’t have a reference design for this and hence we don’t encourage customers taking this approach.

    I hope the above information answers your queries.