This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DLPC230-Q1: working relationship between DLPC230-Q1 and TPS99000-Q1

Part Number: DLPC230-Q1
Other Parts Discussed in Thread: TPS99000-Q1, TPS99000

Hello TI-Team,

The DLPC230-Q1 is a controller for the DMD and the timing of the RGB LEDs in the HUD. It requests the proper timing and amplitude from the LEDs to achieve the requested color and brightness from the HUD across the entire operating range. It synchronizes the DMD with these LEDs in order to display full-color video content sent by the host.

do you have a signal example preferably in respect to time explaining how the two components DLPC230-Q1 and the TPS99000-Q1 interact with each other?

I want to understand which signals are used in order to control the state of the micromirrors and the LEDs properly in order to get the right color.

Thank you in advance.

Taha Agacdograyan

  • Hello Taha,

    The main signals used for LED timing are the LED enable signals, R_en B_en and G_en.  These are generated by the DLPC230-Q1 and sent to the TPS99000-Q1.  The TPS99000 then uses these signals to control the RGB enable FETs to turn the LEDs on and off.

    The exact timings of these signals depend on a lot of factors, but they are stored in the flash file on the DLPC230.  In general the RGB timing is split up into 3 separate allocations to set the best brightness and colorpoint performance for the LEDs, at a 60Hz framerate. This is then further broken up into 2 subframes, each representing half of the frame brightness.  The large sections of R, G, and B light are then again split and re-organized into small sections of individual color that are cycled through very quickly.  This organization will be different for each flash configuration using the DLP composer tool. The small segments are needed to increase the color refresh rate of the display to avoid color breakup artifacts from the vibrations in the vehicle.  The result is a color refresh rate of about 10x the 60 Hz input.

    Please let me know if you have more questions about the specific signals.

    Regards,

    Jackson

  • Hello Jackson,

    ok i understood so far. And can you tell me how the LED_signals are synchronized with the micro-mirror positions?

    When does the DLPC knows to set the LED enable signals AND DMD control signals?

    I assume the DMD positions are set with the sub-lvds signals.

    Is there a correlation with the sub-lvds signals and the LED enable signals?

    In the data sheets for TPS99000 and DLPC230 the signals are described separately from each other, I would like to understand more of how they collaborate.

    Regards,

    Taha

  • Hi Taha,

    The LED signals and the micro mirror positions are indeed related. Both are generated from the same sequence timing file that is stored with the ASIC flash.  Each video frame that is displayed constitutes what we call the DMD sequence.  It is the timing of LED enable signals and micromirror positions that generates the video images.  

    The video content for each frame is broken up into what we usually call bitplanes, which are (for LED projectors) combinations of one LED enable signal and one DMD image pattern.  There will be many bitplanes for each color that repeat frame by frame.All these distinct color and image combinations are displayed very quickly, as fast as several microseconds, and integrated by your eye to create the various shades of color all around the display that you see as a single image.

    The LED enable timings are matched to the DMD bitplanes because they are both generated from the same source (DLPC230), but then the DMD display data is sent over LVDS while the LED signals are sent through the TPS99000 to the LED driver circuit.  As long as the LED driver rise and fall times are fast enough the signals match up.  Typical requirements for LED driver rise and fall times for this applications are on the order of ~1us.

    Best Regards,

    Jackson