ADPD4101 errata and BPF question

In one of the answers on this forum about the ADPD4101 power sequence, it says:

You can skip the sequence in the "Errata for Preliminary Datasheet", which is no longer needed for ADPD4101 part with chipID 0x02C2

Can I get a link to the Errata, please? I couldn't find it in the documentation section.

What drives the shape of the BPF waveform? Is it the reflection coefficient of the surface the emitter/detector are aimed at or? What if the sensor is moving around - will the zero crossing point change?

  • 0
    •  Analog Employees 
    on Jan 11, 2021 8:19 PM

    Hi HarjitS,

    The Erratta is only applicable to ADPD4100/4101 parts with chipID of 0x01C2. Below is the description in the Errata:

    INITIALIZATION SEQUENCE FOR THE ADPD4100/ADPD4101
    The ADPD4100/ADPD4101 requires a certain initialization sequence at every power-up of the device. This document addresses the
    initialization sequence as an errata sheet for the ADPD4100/ADPD4101 preliminary datasheet revision 8.
    At every power-up of the ADPD4100/ADPD4101, please use the following register sequence:
    1. GPIO0 must either be driven to, or pulled up to, IOVDD at the start-up. This can either be performed by driving the GPIO0
    pin high from the microcontroller or by a weak pull-up to IOVDD (>1MΩ).
    2. Write register 0x00B5 to 0x0004. This writes REGISTER_INIT bit to 1.
    3. Write register 0x00B5 to 0x0000. This writes REGISTER_INIT bit to 0.
    4. If GPIO0 is driven high by the host, it can be released at this point.

    Regarding the BPF, it has passband of 100 - 390 kHz. The waveform after BPF mainly determined by the pulse width, the time response of LED(s) and PD(s). If the sensor is moving around, it essentially created a motion artifact and the amount of reflected photons changes.

    Thanks!

    Glen. B