LSM6DSO Pin 3 (SCx) connection in Mode 1 and simultaneous power-up concerns
Hi sir,
I have a question regarding the hardware connection of Pin 3 (SCx) on the LSM6DSOW when operating in Mode 1.
According to the datasheet, Pin 3 should be connected to VDDIO or GND in Mode 1
. However, in our current design, this pin is connected to an MCU GPIO to maintain hardware compatibility with another project that utilizes the Sensor Hub (Mode 2) feature. Our intention is to drive this GPIO LOW to satisfy the Mode 1 requirement.
We have a concern regarding the power-up sequence: In our system, the IMU and MCU are powered simultaneously. However, there is a short delay during the MCU's boot-up phase before the GPIO can be initialized and driven LOW. During this window, Pin 3 of the LSM6DSOW will be in a floating state (input without pull-up)
.
Our proposed software flow is as follows:
System power-up (IMU and MCU together).
MCU drives the Pin 3 GPIO to output LOW as soon as its firmware initializes.
MCU issues a Software Reset (SW_RESET in CTRL3_C, 12h) to the LSM6DSOW
.
Proceed with normal initialization (e.g., reading WHO_AM_I, setting ODR).
My questions are:
Is this "GPIO LOW + Software Reset" approach acceptable for ensuring device stability? Specifically, we want to confirm if the LSM6DSOW can successfully receive and execute the SW_RESET (12h) command via the I2C interface even if Pin 3 was momentarily floating during the initial power-up phase.
Is there any timing requirement (e.g., a minimum delay) after driving the GPIO LOW before issuing the SW_RESET command?
Thank you for your technical support.
