• RE: I would like to use a SPI for power savings. Does the ADPD103 only have an I2C option?

    Yes, the ADPD103 only has an I2C option. However, there is a recently released upgrade to the ADPD103 called the ADPD105 and ADPD107. These are backwards compatible to the ADPD103, but have better noise performance at lower power points, and the ADPD107…

  • ADPD107 External sampling sync trigger


    I received a question about sync trigger of ADPD107 from our customer.

    The customer input a trigger signal (25Hz) to GPIO0. And he checked PDC timing. But the PDC timing has variation around +/-1usec as the trigger signal.  Is this ADPD107's specification…

  • RE: ADPD107 TIA ADC Mode Timing

    If you are starting from a non-saturated state on both the ADPD103 and the ADPD107 and you increase the signal level you will eventually saturate the ADC before you saturate the TIA. When this happens, the output of the ADC will clip. If you continue…

  • RE: ADPD107 Software reset

    Hi Kevin,

    Then, the software reset completes in one clock time of SPI, right? If no, could you please advise me the actual time of the software reset for my reference?


    Do the setting and data in FIFO also clear by the software reset?

    Best regards…

  • Performing Noise analysis of ADPD107 SPO2 signal chain containing photo diodes

    Dear all,

    Request you to provide some pointers related to performing noise analysis for ADPD107 SPO2 Based signal chain containing Photodiode and Leds. Any application note to refer to will be helpful.


  • Strange Optical Signal Noise with ADPD107

    Hi , I am currently using the ADPD107 for PPG sensing. I am getting some strange looking noise on the optical signal inconsistently. It seems to be more of a problem when sampling at lower LED brightnesses, but it is not always consistently noisy…

  • ADPD107 Drive current settings not matching datasheet formula

    Hi ,

    We are seeing what looks like inaccuracies in the drive current on the ADPD107. The datasheet says the drive current should be:

    LEDPeak = (50.3 + 19.8 * ILED_COARSE) * (0.74 + 0.022 * ILED_FINE) * (0.4 + 0.6 * ILED_SCALE)

    We are trying…

  • RE: ADPD103 Drives a LED ( 5V~7V@20mA )

    For some reason I assumed that we were talking about the ADPD105 since it's the latest device in the family. If this is a new design, then you should be looking at the ADPD105 (or ADPD107 if you wanted SPI). The ADPD105 is backwards compatible. There…

  • RE: ADPD105 TIA ADC mode configuration

    Hi Ganesh,

    The maximum sampling rate of our evaluation tool is going to be limited by the communications interface over the UART. In practice, the fastest I've ever been able to get the Wavetool to run is ~1000Hz for single channel operation, 16b data…

  • ADPD105/107 gain and dark skin conditions

    While testing the ADPD107 on darker skin I have had trouble getting the response into a decent range for heart rate sensing even at max LED current, max gain, photodiode through single amp etc. Aside from increasing the optical efficiency and changing…