Q. ADPD4101 total supply current (max.)

Hello.

How much current is required to operate all the functions of ADPD4101?

The datasheet states that the maximum current is 400mA when multiple LED drivers are used simultaneously.

It seems that it does not require a large current other than the LED driver.

Thanks.

Leo

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  • 0
    •  Analog Employees 
    on Feb 5, 2021 8:45 PM 2 months ago

    Hi Leo,

    The ADPD4101 is a power efficient part and its average supply current is determined by many factors such as sampling rate, # of timeslot, # of pulses, etc. For instance, the AFE current is about 0.92 mA for running 12 timeslot of 16x2us pulse PPG at 100 Hz sampling rate. Typically, the instantaneous LED current is much higher than the AFE current in a PPG system. The ADPD4101 uses short pulses in its normal mode to significantly reduce the average LED current / power consumption.

    The maximum current of 400 mA is the up limit of the LED drivers. With the short pulse approach, the average LED current can be very small so that low system power consumption can be achieved.

    Regards,

    Glen. B

  • Hi Glen,

    Thanks for the quick reply.

    Please recommend the maximum output current specification of the two regulators.

    1. Regulator connected to AVDD, DVDD(1.8V)

    2. Regulator connected to IOVDD(3.0V)

    ex) Max. output current: First regulator > 100mA and Second regulator > 400mA

    Regards,

    Leo

  • +1
    •  Analog Employees 
    on Feb 8, 2021 4:50 PM 2 months ago in reply to Leo Park

    Hi Leo,

    The peak 1.8V VDD current is 3.8mA for 1-channel operation, refer to Table 2 in the ADPD4100 data sheet. It should be less than 7.6 mA for 2 channels. That said, 10mA should be sufficient for the 1.8V regulator.   

    If you plan to use the 3.0V for LEDs, then it should be >400 mA for the highest current demand. The IO operation current for ADPD4100 GPIO is very low.

    Regards,

    Glen. B

Reply
  • +1
    •  Analog Employees 
    on Feb 8, 2021 4:50 PM 2 months ago in reply to Leo Park

    Hi Leo,

    The peak 1.8V VDD current is 3.8mA for 1-channel operation, refer to Table 2 in the ADPD4100 data sheet. It should be less than 7.6 mA for 2 channels. That said, 10mA should be sufficient for the 1.8V regulator.   

    If you plan to use the 3.0V for LEDs, then it should be >400 mA for the highest current demand. The IO operation current for ADPD4100 GPIO is very low.

    Regards,

    Glen. B

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