How to calculate the current in low power mode 1 with slope/any-motion interrupt?

[Frankie]

Am i correct for the following calculation?

In order to suppress false triggers, the interrupt is only generated (cleared) if a certain number N of consecutive slope data points is larger (smaller) than the slope threshold given by (0x28) slope_th. This number is set by the (0x27) slope_dur bits. It is N = (0x27) slope_dur + 1 for (0x27).

In EDT the duration of the wake-up phase depends on the number of samples required by the enabled interrupt engines.

e.g. slope_dur=1, bandwidth=500Hz(tut=1ms), sleep time=6ms

tactive = tut + tw,up1 - 0.9 ms (or tactive = tut + tw,up2 - 0.9 ms)

N=slope_dur+1=2, so tactive=1ms*3+1.4ms(typical value)-0.9ms=3.5ms?

and the estimated current will be (6ms*1.4uA+3.5ms*130uA)/(6ms+3.5ms)?

[o_o · Accepted solution]

Frankie,

I put your data into my pre-made current consumption calculation spreadsheet and you can expect ~50uA of current consumption, and a data rate of ~100Hz with the settings you gave me.

[Frankie]

thanks, but it looks like  the number of samples for slope interrupt engine are not taken into account in the table of BW=1KHz 

[o_o]

Not directly, but you can adjust the t_active time according to the number of samples, and see how this impact the current consumption at different data rates.