LIS2DW12 Current Consumption.

[VMali.2]

Hello STMicroelectronics Support Team,

I am currently working on a development project where I'm utilizing the LIS2DW12 accelerometer. However, I've encountered an issue with the current consumption of the accelerometer on our custom board. I would appreciate your assistance in resolving this matter.

Configuration Used:

lis2dw12_block_data_update_set(&dev_ctx1, PROPERTY_ENABLE);

lis2dw12_full_scale_set(&dev_ctx1, LIS2DW12_8g);

lis2dw12_filter_path_set(&dev_ctx1, LIS2DW12_LPF_ON_OUT);

lis2dw12_filter_bandwidth_set(&dev_ctx1, LIS2DW12_ODR_DIV_4);

lis2dw12_power_mode_set(&dev_ctx1, LIS2DW12_HIGH_PERFORMANCE);

lis2dw12_data_rate_set(&dev_ctx1, LIS2DW12_XL_ODR_25Hz);

Issue:

After incorporating the LIS2DW12 accelerometer into our custom board, we noticed a current consumption of approximately 1.5 mA. However, upon removing the accelerometer, the current consumption dropped to 1.5 uA. We expected the accelerometer to be a low-power device, and this discrepancy in current consumption has raised concerns.

Suggestions Tried:

1. Verified that the accelerometer is operating in the low-power mode (LIS2DW12_LOW_POWER) rather than high-performance mode.
2. Reduced the Output Data Rate (ODR) to a lower value that still meets our application requirements.
3. Adjusted the Full Scale Range to a lower value (e.g., LIS2DW12_2g).
4. Reviewed and considered disabling the filter path (LIS2DW12_LPF_DISABLE) to reduce power consumption.
5. Disabled the Block Data Update feature (PROPERTY_DISABLE) if it is not required for our application.
6. Ensured a stable and noise-free power supply to the accelerometer.

Despite these efforts, we are still experiencing higher than expected current consumption with the LIS2DW12 accelerometer.

Could you please provide us with further guidance or suggestions on how to achieve minimum current consumption with the LIS2DW12 accelerometer? We would greatly appreciate your expertise and assistance in resolving this issue.

Thank you in advance for your support.

Regards,

Vitthal.

[Federica Bossi]

Hi @Vitthal Mali​ ,

Welcome to ST Community!

Can you please share your schematic?

[VMali.2]

Hello Federica Bossi (ST Employee)

 

 

We encountered a situation where the same SDA and SCL pins of our NRF52833 Microcontroller are connected to both an accelerometer and a temperature sensor. During our investigation, we discovered that the CS (Chip Select) pin of the LIS2DW12 accelerometer has an internal pull-up register. As a result, we removed the R3 register and connected 4.7k pull-up resistors to the SDA and SCL lines. CS Pin of LIS2DW12 is kept open.

We would appreciate your support in confirming whether our approach is appropriate for this configuration. Specifically, we would like to know if connecting the pull-up resistors to the shared SDA and SCL lines is a suitable solution. Additionally, we would like to ensure that this setup will not cause any conflicts or issues with the communication between the NRF52833 microcontroller and the devices connected to the shared bus.

Regards,

Vitthal.

[Federica Bossi · Accepted solution]

Hi @Vitthal Mali​ ,

First I suggest you to remove R4 and R5 since they are output push-pull.

If you want to use them in open drain configuration please enable PP_OD in reg 22h.

If this solves your problem, please mark my answer as "Best Answer" by clicking on the "Select as Best" button, this can be helpful for Community users to find this solution faster 🙂