MMA9555L power consumption issue

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MMA9555L power consumption issue

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aminekechouindi
Contributor I

Hello,

We are developing a project based on MMA9555L pedometer. We purchased MMA9555L DK and some samples from DIGIKEY distributors.

We notice an over power consumption around 1.6mA with the 4 samples.

Following our MMA9555L Setup:

- VDDA = VDD = 1.8 V

- I2C Communication interface is selected, (a pull-up of 1.8 MΩ is set on RGPIO3/SSB, as with default setting after startup this pin is driven low by MMA) with 10KΩ pull-up resistors on SCL/SDA lines.

We are pretty sure about PCB as when replacing purchased samples by DK’ chip we come back to normal consumption around 85 uA. Also on the DK we place a sample chip and again we observe the over consumption.

From SW point of view, we verify that there is no difference between samples and DK chips (except the device_id)

Following there is a dump of device main application settings (it is corresponding to factory/default configuration)

device_id = x47d341f0, rom_ver = x0101, fw_ver = x0202, hw_ver = x0106, build_ver = x0341

gpio_map /gpio x04 parameters (application = xff, status_bit_position = x00 polarity = 0)

gpio_map /gpio x05 parameters (application = xff, status_bit_position = x00 polarity = 0)

gpio_map /gpio x06 parameters (application = xff, status_bit_position = x00 polarity = 0)

gpio_map /gpio x07 parameters (application = xff, status_bit_position = x00 polarity = 0)

pedometer_configuration/user (gender = 0, height = 175, weight = 80, step_length = 0)

pedometer_configuration/sleep (acceleration_threshold = [0 .. 0], debounce_counter_mode = 0, debounce_counter_threshold = 1)

pedometer_configuration/steps (acceleration_threshold = [1 .., time_window = 4, minimum_count_threshold = 3, coalesce_threshold = 11)

gpio_configuration (direction = x0f, enable = x0f, data = x05)

 

The only visible difference is the chip MARKING (Note last 3 letters do not math data sheet description)

DK chip (Correct consumption): 263 9555 BXA

samples chip (over consumption): 263 9555 BWL

Questions:

Apart from the firmware, is there any non-volatile configuration supported by the MMA that can explain observed over consumption.

Is there any explicit difference between BXA / BWL chips.

 

Amine.

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aminekechouindi
Contributor I

Hello,

We figure out the issue, it is related to RESET configuration of Sleep/Wake application.

Once the Sleep/Wake application is configured (with default setting defined on data sheet) We come back to correct power consumption:

Following Sleep/Wake configuration after power on:

946757707|INFO |MMA9555L| sleep_wake.configuration/wake_sensitivity_threshold = 160, doze_time_threshold = 4000 (1/488 s), long_time_threshold = x07, short_time_threshold = x06
946757707|INFO |MMA9555L| sleep_wake.configuration/low_power_mode_enable = 0, irq_enable = 0, doze_mode_enable = 0, doze_long_short_afe_period_enable = 0, sleep_mode_enable = 0

We note that SCHEN bit is set to 0 (This is in contradiction with data sheet page 86)

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JackITB
NXP Employee
NXP Employee

Hello Amine,
Date code (BXA / BWL) marking difference simply indicates that those devices were manufactured at a different time (roughly 3 months delta) which obviously should not impact the consumption.

I suggest you initiate a Service Request through your supply channel.
Regards,      Jacques.

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