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ADE7858A about DSP_RUN=1 setting

Product Number: ADE7858A

Hello

ADE7858A datasheet rev.D P.45 describes below.

"during the chip power-up and DSP reset cases, it typically takes about 1.2 seconds for an FS/1000 signal to be settled"

I think that it takes some time addition to settling time after DSP RUN=1 (register 0xE228) from above description.

How long does it take for FS/1000 signal to be settlied after DSP of ADE7858A is set to RUN=1(0xE228) ? 

( 1.2 seconds or settling time only ?)

Regards,

Teli

  • in the datasheet it shows IRMS setting of 440ms  from 0 to full-scale. On power up there is a sequence. Apply vdd, toggle reset, wait for reset done irq, write registers then run bit. This take time and you need to take this into account. 

    It take about 40ms from power applied to reset done.  1.2sec seems right for setting to 1% from power up. 

    Dave

  • Thank you for your answer.

    Please let me know your advice about the time in my case.

    I plan to use ADE7858A as follows:

    1: Power up and reset is done (40ms)

    2. CPU executes the control of other IC for a few seconds ( at leaset over 1.2sec)

    3. CPU writes registers (RUN bit and etc)

    Which 1.2 second or IRMS settling time (440ms @50Hz intergrator off)  do I need for settling after above 3 ?

    I would like to know whether there is any prbolem with 440ms or not in above case.

    Regards,

    Teli

  • 1.2sec is from power up. After rms has settled (1.2s) a fullscale to 0 or 0 to full-scale require 440ms to settle to 99%

    Dave