• Power supply

    Christoph Tack • 03/27/2019 at 20:03 • 0 comments

    Powering the LED array

    The LED array has the following power consumption:

    3V0
    		0.9A
    3V31.1A
    3V51.5A
    3V71.7A
    3V92.0A

    The LED array seems as bright on 3V0 as on 3V9.  3V0 is really a minimum voltage.  Lower voltages leave artefacts in the LED array.

    Using buckboost module

    The current draw from the LED array is simply too big for the AliExpress 32757272432 and the AliExpress 32892547111.

    Using boost module followed by buck module

    I used the HWA YEH SX1308 boost module and set it to 5V output.  Somehow the IC got fried and I replaced it with a MPS MP3221.  The buck module is the WAVGAT XM1584.  It has been set to 3V3 output.

    This solution works well for a few minutes, but then the components are getting hot and the modules repeatedly enter a thermal shutdown state.

    This solution draws about 1.7A from a 3.3V power supply.

    Using linear regulator

    AP7363-33D-13 (IC REG LINEAR 3.3V 1.5A TO252)

    Adding an MBRS240L schottky diode after the 3V3 output of the LDO reduces the voltage to the LED array to 2.96V.  This reduces current consumption by about 500mA.