What is the ADXL375?

    The ADXL375 is a low-power, 3-axis digital MEMS accelerometer that provides high resolution (98mg/LSB) measurement up to ±200g with a bandwidth of up to 1KHz. The ADXL375 is supplied in a 3mm × 5mm × 1mm, 14-lead LGA package.

     

    What type of applications use the ADXL375?

    The target application for ADXL375 is the measurement of shock and other high-g events.  Accurate shock information can be valuable in a wide range of applications, such as profiling the usage of leased assets or sensitive equipment, shipping data loggers, and accounting for motion artifacts. In contact sports, biking, or in the military, crash or impact metrics (such as magnitude, point of contact, and direction) can be used by doctors to better diagnose concussion or head trauma resulting from accidents.

     

    What is special about the ADXL375?

    The ADXL375 provides a compact, 3-axis and low power solution compatible with portable and battery powered applications but with sufficient dynamic range and bandwidth to accurately capture the shock events.  The current consumption at the maximum output data rate of 3200Hz is ~145µA and scales proportionally with data rate to as low as 35µA. The ADXL375 can be programmed to monitor single or double (primary and secondary) shocks along any combination of X, Y, and/or Z axes. In addition, the entire shock profile can be captured for further analysis using an integrated 32 sample memory.

    How does the ADXL375 add value for the customer?

    The ADXL375 provides a way of differentiating and recording shock events of interest based on both amplitude and pulse width. The shock detection function allows users to define a minimum threshold and time duration for the shock. This allows users to distinguish between two shock pulses where both pulses can exceed the minimum threshold setting, but differ in their sharpness.

     

    In addition to the profile or time history, direction can also be an important parameter in determining the severity of a shock event. The ADXL375 allows monitoring of shock events in all 3-axes so that both the profile and direction can be accurately ascertained.

     

    The ADXL375 also provides the option of capturing the entire shock profile for further analysis with no intervention from the host processor. This is achieved using the shock interrupt registers in combination with the accelerometer’s internal FIFO. Typically, in order to capture transient events the accelerometer needs to be continuously polled by the host processor at high data rates, significantly increasing the overall system power consumption.  The ADXL375 offers considerable power savings by letting the processor be in a low power state for the majority of the time especially in applications where shock events are rare and can occur over periods of months or years.

     

    What are the critical performance parameters of the ADXL375?

     

    • Bandwidth up to 1KHz
    • Range = ±200g, tri-axis
    • Noise density = 5mg/√Hz
    • Current consumption = 35µA to 145µA