2020-07-30 02:42 AM
I could not find this information in the datasheet or app note (just power down, LP, NM, and HP modes).
2020-07-30 04:45 AM
Hi @PBitt.1 , please note that the sleep mode is another name for the power down mode. You can set in sleep mode the accelerometer and the gyroscope separately, while power down mode is more relate to both sensors sleeping. For this reason, the table below is the reference one (see also AN4650 p.21).
Regards
2020-07-30 05:20 AM
Hi Eleon,
Thank you, it is a little confusing as Table 16 provides information on transition times from power down to sleep/active and from sleep to active as different things (and from active accelerometer + gyroscope sleep to others).
Section 3.5 states:
"While the gyroscope is in Sleep mode the circuitry that drives the oscillation of the gyroscope mass is kept active. Compared to gyroscope Power-Down, turn-on time from Sleep mode to Low-Power/Normal/High-Performance mode is drastically reduced.If the gyroscope is not configured in Power-Down mode, it enters in Sleep mode when the Sleep mode enable (SLEEP_G) bit of CTRL4_C register is set to 1, regardless of the selected gyroscope ODR."
I could not understand what is the practical difference. As stated above, the gyroscope sleep mode should have a faster turn-on time. I cannot see this happening without a current penalization.
Is it safe for me to assume:
Gyroscope sleep mode current consumption equals power down consumption.
Gyroscope turn-on time from sleep is just the time to discard the first 2 measurements (opposed to 80ms max from power down to active mode)
Thank you,
Paulo.
2020-07-30 06:26 AM
This happens because the circuitry part of the gyro is "sleeping" while the accelerometer is however still running. In theory, since the MEMS finger capacitors are high impedance node, even if you power them with a difference of potential you will not have a conducting path, so ho additional current consumption.Btw, when gyro is in sleep mode, the accelerometer should be running, so the main contribution is the accelerometer one. Regards