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DLPA3005: Is the DLPA3005DPFD a drop-in replacement for the DLPA3000DPFD?

David Knott
Prodigy 65 points
Part Number: DLPA3005
Other Parts Discussed in Thread: DLPA3000, DLP4710EVM-LC

Tool/software:

Is the DLPA3005DPFD a drop-in replacement for the DLPA3000DPFD? I have a circuit working with the DLPA3000DPFD device. Can the device be replaced with a DLPA3005DPFD? I want to use the DLPA3005 to get the increased forward voltage for LEDs. The DLPA3005 output can go to a higher LED voltage.

  • 0
    Prodigy 65 points

    The circuit will be used for LED currents less than 6A. Is the DLPA3005 a drop in replacement when the LED current is 2A or less? The datasheet shows that the DLPA3005 needs external MOSFETS if a LED current as high as 16A is needed. What will happen if the DLPA3005 is used in the same circuit that works for a DLPA3000 when the LED current is 2A or less?

  • 0 in reply to David Knott
    Prodigy 65 points

    Comparing datasheets and circuits, it depends on whether the DLPA3005 has the same current drive on the signals CH1_SWITCH, CH2_SWITCH, and CH3_SWITCH. These signals are active low. Can these signals take 2A the same as the DLPA3000? Table 5-1 Pin Functions on the DLPA3005 datasheet has the same description as the DLPA3000.

  • 0 in reply to David Knott
    TI__Genius 11555 points

    Hello David,

    The DLPA3005 has to use external power MOSFETs for illumination, please refer to the reference design on DLP4710EVM-LC. That means you need to change your current design. 

    The max LED currents on DLPA3000 is 6A, if you use LED current less than 2A, why don't you just keep your design as DLPA3000?

    Regards,

    Lori 

  • 0 in reply to Lori Wang
    Prodigy 65 points

    On the DLPA3005 datasheet, Table 5-1 Pin Functions shows the following:

    CH1_SWITCH Low-side MOSFET switch for LED Cathode. Connect to RGB LED assembly.
    CH2_SWITCH Low-side MOSFET switch for LED cathode. Connect to RGB LED assembly
    CH3_SWITCH Low-side MOSFET switch for LED Cathode. Connect to RGB LED assembly.

    On page 48 of the DLPA3005 datasheet, Figure 8-3 shows CH1_SWITCH, CH2_SWITCH, and CH3_SWITCH connected directly to the cathode of the LEDs without using external MOSFETs.

    This means that parts of the DLPA3005 datasheet show the device using the CHn_SWITCH signals directly, and not external MOSFETS driven by the CHn_GATE_CTRL signals.

    The advantage of using the DLPA3005 is that its LED voltage VLED_ANODE can go as high as 15.5V. On the DLPA3000, the LED voltage can only go up to 7.2V.

    If the CH1_SWITCH, CH2_SWITCH, and CH3_SWITCH signals are used, will the circuit still work provided the current is 2A or less? It depends on whether the internal circuitry of the DLPA3005 is the same as the DLPA3000 for these signals.

  • 0 in reply to David Knott
    TI__Genius 11555 points

    Hello David,

     I'm sorry for the confusion, Figure 8-3 in the DLPA3005 datasheet is not correct for these CHX_SWITCH and CHX_GATE_CTRL pins. We will need to fix this diagram.

    Please refer to the schematic, CHX_GATE_CTRL need to connect to MOSFETs which is different with DLPA3000 design. 

    Regards,

    Lori 

  • 0 in reply to Lori Wang
    Prodigy 65 points

    If a design follows figure 8-3 in the DLPA3005 datasheet, what will happen? Will it work?

    If the CH1_SWITCH, CH2_SWITCH, and CH3_SWITCH signals are used, will the circuit still work? Is the internal circuitry of the DLPA3005 the same as the DLPA3000 for these signals?

  • 0 in reply to David Knott
    TI__Genius 11555 points

    Hello David,

    The figure 8-3 in the DLPA3005 datasheet is not correct as I mentioned before. Please refer and compare the schematic for DLPA3000 and DLPA3005, then you will see the different. The internal design for the illumination block are different.

    Regards,

    Lori 

  • 0 in reply to Lori Wang
    Prodigy 65 points

    If the three MOSFETs were used for the CHX_GATE_CTRL signals, but the other two MOSFETs were not used, would the circuit work? If the other two MOSFET transistors are missing, will the circuit be able to drive the LEDs? On the lightcrafter evaluation module, these two transistors are connected to ILLUM_A_SW pin 31, ILLUM_LSIDE_DRIVE pin 27 via resistor, ILLUM_HSIDE_DRIVE pin 26 via resistor, and ILLUM_A_VIN pin 30. Are these MOSFETS needed if the LED current is 2A or less?

  • 0 in reply to David Knott
    TI__Genius 11555 points

    Hi David,

    If you want to use DLPA3005 to replace with DLPA3000, then you have to use these five MOSFETs. 

    Do you have your own custom design board or you are using TI EVM? What's he controller and DMD you are using? 

    Regards,

    Lori