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DLP3010: LED driver for very low brightness application 0.01fL to 50fL

nathan glatz
Prodigy 40 points
Part Number: DLP3010
Other Parts Discussed in Thread: DLPC3433, DLPA2005, DLPA2000, DLPC3438

Currently using DLPC3433, DLPA2005, DLP3010

Needing to get brightness to a very low limit of 0.01fL to 50fL.  We are using a projector system to project through a waveguide. There is some light inefficiencies with the waveguide itself but we cant seem to get the brightness low enough for our application.

DLPA2005 appears the lowest setting is 100mA and DLPA2000 is 14mA.

Using DLPA2000 we still cant get brightness low enough for our application.  We still need roughly 600mA to hit our applications' max brightness. 

Is there a ways to reduce the brightness even more with DLPA2000?  

  • possibly changing the duty cycle of each LED? currently G50% R25% B25%
    • adjusting LED current via I2C DLPC
  • would additional circuitry to change duty cycle cause dlpa2000 to not function properly? 
  • is there a limitation of how much light is needed for the DMD micro-mirrors?
  • Different LED drivers options available? 

  • 0
    TI__Mastermind 23040 points

    Hello Nathan,

    Have you considered the "AR version" for the DLPC3433 firmware. Please go to firmware selector tool and 

    Firmware Selector (ti.com)

    Please select "DLPC343 AR/DLPC3438_AR under controller.

    Please refer to the release note. The Look 1 and Look 2 have 50% and 25% dark time. You can reduce the brightness by nearly 50% and 25% at same current level using these looks You can switch between looks during run time using an I2C command.

    Release Notes (ti.com)

    The DLPA2000 is the best PMIC option for this chipset.  

    nathan glatz said:
    possibly changing the duty cycle of each LED? currently G50% R25% B25%
    • adjusting LED current via I2C DLPC

    Using Looks with dark time is preferred option.

    nathan glatz said:
    would additional circuitry to change duty cycle cause dlpa2000 to not function properly? 

    Duty cycle and dark time are programmed through firmware. No impact on hardware

    nathan glatz said:
    • s there a limitation of how much light is needed for the DMD micro-mirrors?
    • Different LED drivers options available? 

    DMD mirror are reflective surface, there is no minimum incident  light requirement for normal operation.

    regards,

    Vivek

  • 0 in reply to Vivek Thakur
    Prodigy 40 points

    We have not considered AR firmware.  We are going to look into this soon.

    Some follow up questions:

    What is happening to the LED drive during "dark time"?  is the duty cycle for each LED the same but there is some kind of PWM within each LED duty cycle time? diagram/sketch below is visually what i am asking on clarification. is there any way to get this type of option? 

    Can we PWM via I2C with toggling RED,GREEN, and BLUE LEDs? 

  • 0 in reply to nathan glatz
    TI__Expert 5450 points

    Hello Nathan,

    Please allow us some time to look into your questions.

    Regards,

    John

  • +1 in reply to John McKnight
    TI__Mastermind 23040 points

    Hello Nathan,

    Thank you for your patience...

    nathan glatz said:
    What is happening to the LED drive during "dark time"?  is the duty cycle for each LED the same but there is some kind of PWM within each LED duty cycle time? diagram/sketch below is visually what i am asking on clarification. is there any way to get this type of option? 

    During dark time, LEDs are off. For example, at 60 Hz frame rate with 50% dark time, the complete image is displayed in first half of the frame (8.3 ms) and LED are OFF for second half of frame.

    The LEDs are not modulated as shown in the image. This feature is not supported.

    The DLP controller converts the RGB (24 bit) image into bit planes of R, B and B. where each bit plane a different weight in order to generate gray value.  

    During a color refresh (ex RED), one or more-bit planes may be displayed. That LED remain ON during the color refresh. PWM is achieved through cumulative ON duration of DMD mirrors.

    nathan glatz said:
    Can we PWM via I2C with toggling RED,GREEN, and BLUE LEDs

    This feature is not supported.

    regards,

    Vivek

  • 0 in reply to Vivek Thakur
    Prodigy 40 points

    thank you this was helpful.