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CCS / LP8860-Q1:Fault pin

Part Number: LP8860-Q1

Tool/software: Code Composer Studio

hello~

i have a question

I set EEPROM 0X86 to 0X6F

Vin = 12V, why Fault pin  not  high

i read 0x0F=0x40

  • LED current and LED voltage how to use the value of the register?
  • In reply to matt chen:

    Hi Matt,

    Sounds like Fault pin and VIN OVP Fault Flag are working ok. Fault pin is open-drain so should be pulled low when fault event occurs and pulled high for normal operation or after doing a CLEAR fault.

    Not sure I understand your last question. Could you be more specific into which registers you are referring to?

    Best Regards,

    Salome
  • In reply to Salome Ramirez Carrion:

    Hello~

    I want to express , DISP_CL1_BRT and DISP_CL1_CURRENT two registers can be changed
    LED brightness
    How do I use these two registers to calculate  current value and  voltage value

  • In reply to Salome Ramirez Carrion:

    There is any possibility that I will FAULT PULL HIGH
    In the failure did not happen to be pulled to LOW

    Incidentally, the cause of the LED flicker?
  • In reply to matt chen:

    Hi Matt,

    DISP_CL1_CURRENT[11:0] sets the actual maximum current which can be same or lower than DRV_LED_CURRENT_SCALE[2:0] value, which sets the max scale or maximum current limit.

    DISPL_CL1_BRT determines the brightness or duty % if BRIGHTNESS REGISTER is used as the display brightness mode, or it will also affect  brightness % if PWM INPUT DUTY x BRIGHTNESS REGISTER mode is used.

    Output voltage will be determine by your LED load forward voltage (typ 3V per LED) plus headroom voltage at the output pin ~1-2V.

    Best,

    Salome

  • In reply to Salome Ramirez Carrion:

    ok,i have a new question

    How setting boost_OVP and boost_OCP THRESHOLD ??

    because EEPROM not setting boost_OVP OCP value
  • In reply to matt chen:

    Hi Matt,

    Boost OCP can be limited with BOOST_IMAX_SEL[2:0] register.

    Boost OVP is preset condition, no register is available for setting OVP. Boost OVP fault will be triggered when boost output voltage raises above ~1.6V from expected adaptive boost voltage or if output voltage is being set in manual mode, OVP will be set if boost output voltage raises above ~1.6V from initial boost voltage setting.

    Best Regards,

    Salome