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LED APIs and LED Driver

Hiroaki Tanikoshi
Intellectual 675 points
Other Parts Discussed in Thread: DLPC200, LM3431

Hello,

I would like to know time chart from issuing API function (DLP_LED_SetLEDintensity) to blightness actually changed.

Also, I know OSRAM LED Driver module is verified in LightComandar, but If I would like to chage the LED driver, is there any recommended TI LED driver IC?

We are serching 18A LED current now.

 

Best regards,

Hiroaki

  • 0
    TI__Mastermind 30875 points

    Hello Hiroaki-san,

    The DLPC200 implemented proprietary SPI protocol to communicate with OSRAM LED Driver. In this configuration the DLPC200 SPI master bus is connected to SPI slave of OSRAM LED Driver.

    If you would like to use with other LED driver then you must look at PWM based LED control option from DLPC200. These are documented in DLPC200 SPI interface specification  http://www.ti.com/lit/ug/dlpu005b/dlpu005b.pdf  section 6.54 ConfigurePWMPeriod (0x0035) and 6.55 ConfigurePWMDutyCycle(0x0036).

    Normal LED drivers taken PWM signal for LED current control along with LED ON/OFF or LED_ENABLE signals.

    I am not aware of any TI LED driver ICs, you may want to post query on the other forums for LED driver ICs.

    Regards,
    Sanjeev

  • 0 in reply to Sanjeev
    Intellectual 675 points
    Hello Sanjeev,

    Thank you for your answer.
    For LED Driver IC, I'm looking at LM3431 now. I will check what you mentioned in detail.

    BTW, How about timing chart from issuing API function (DLP_LED_SetLEDintensity) to blightness actually changed.
    I'm looking forward to hearing from you.

    Best regards,

    Hiroaki
  • 0 in reply to Hiroaki Tanikoshi
    TI__Mastermind 30875 points

    Hello Hiroaki-san,

    OSRAM LED Driver is very high-end hardware also used in regular projector system. It is powerful enough to apply LED current on frame-to-frame basis.

    DLP_LED_SetLEDintensity -
    After receiving the message to DLPC200 it will write on SPI master port connected to LED Driver. The functionality is synchronized to internal/external VSYNC timing. The driver is also synchronized to VSYNC signal, it the packet received in the current vsync, the actual intensity (DAC) is applied to the next VSYNC.

    Again, this API is more tied to OSRAM LED driver, if you are designing your own, i suggest you to look at PWM based current intensity application.

    Regards,
    Sanjeev