ADPD4100Z led is not blinking

Hi sir,

i am working with adpd4100z  device, i am able  communicate with device through SPI . I have done device configuration registers below mentioned  but led is not blinking.

LED drive i have configured 0x0106 register i selected led3b and led 4b  ,A6  value  that is around 65ma. may i know the where us the problem.

resister r18 i checked voltage 3v is coming and other side led3x pin enabled  still led not responding .

let me know where i am missing

here is the configuration registers

{0x0108U, 0x0000U},
{0x000FU, 0x0006U}, // Enable the 1 mhz
{0x0101U, 0x4101U}, // TS_PATH and prewidth 8us // 0x40DAU //0x4101U
{0x000DU, 0x2710U}, // TS freq 100hz
{0x0021U, 0x0000U},
{0x0023U, 0x0A00U},
{0x0102U, 0x0001U}, // IN1 is connected to channel 1 IN2 dis
{0x0104U, 0xE3C0U}, // TIA_VREF 1.265V Modulate TIA_VERF 1.265V //03C
{0x0103U, 0x5002U}, // Precondition with TIA_VERF and VC1 active TIA_REF +215 mv
{0x0105U, 0x2626U},
{0x0106U, 0xA6A6U}, // selecting LED4B,LED3B and op current 70ma 0xA6A6
{0x0107U, 0x0101U}, // number of analog convertion (single)selected
{0x0109U, 0x0210U}, // led offset 16us and led width 2us 0210
{0x010AU, 0x0043U}, // set intifration width 3us and
{0x010BU, 0x1014U} // 1 us sec incremets lsb,31.25 incremets nano sec

  • i have connected 1.8 volts for analog , 3v connected iovdd from the controller board. i am able to read  and write. from external power source i giving 1.8v but current is not drawing, is that mandatary to draw current any issue   and i am trying to glow led but i count get. 

  • 0
    •  Analog Employees 
    on Sep 1, 2021 2:24 PM

    Hello -

    Can you share your schematics for us to debug the problem? We need to know your LED connections and power supply as well as the decoupling capacitor(s).

    Also it is noticed that both registers 0x0105 and 0x0106 are on in the config, with LED1A and LED2A turned on in register 0x0105 (0x26->105mA for LED1A/LED2A). Please be aware that you can turn on either group A or group B of the LED drivers at anytime, not both.


    Glen B.


  • Hi sir,

    I am working with the adpd4100z development board. i am not having this board schematics. giving the power supply IOVDD 3volts from the nrf52840 and AVDD 1.8 volts from external power supply after turn on the device  is not drawing the current adpd4100z. i am using led led3b and led4b (which is on development board?) with this set i am trying to connect wavetool software but device its not detecting ,is that work with  adi wavetool software? 

  • 0
    •  Analog Employees 
    on Sep 2, 2021 1:54 PM in reply to mahee1

    Hi there,

    We cannot help if we don't have the schematics of your board unless you are using the EVAL-ADPD4100Z-PPG board along with the EVAL-ADPDUCZ board from ADI. The Applications Wavetool works only with microcontrol boards from ADI. Other microcontrol boards may not have the correct firmware for controlling the ADPD4100 sensing board and data transferring.


    Glen B.