ADXL357BEZ Functional Block Diagram — 3-Axis MEMS Sensor, ADC, Digital Filter, FIFO, and Serial I/O (Source: Analog Devices Datasheet)
The ADXL357BEZ is a high-performance, low-noise, 3-axis digital MEMS accelerometer manufactured by Analog Devices. Featuring a 20-bit analog-to-digital converter and selectable measurement ranges of ±10g, ±20g, and ±40g, this device delivers ultralow noise density of 80 µg/√Hz across all axes with minimal 0g offset drift of 0.75 mg/°C. The ADXL357BEZ supports both SPI and I²C digital interfaces and consumes only 200 µA in measurement mode, making it ideal for battery-powered and precision motion sensing applications in structural health monitoring, seismic imaging, platform stabilization, and industrial condition monitoring.
Table of Contents
1. Overview and Core Features
The ADXL357 belongs to Analog Devices’ ADXL35x family of precision MEMS accelerometers, designed to address the most demanding requirements in vibration analysis, tilt measurement, and inertial navigation. The device integrates a 3-axis MEMS sensing element with a high-resolution 20-bit sigma-delta ADC, digital filtering, and a 96-sample FIFO buffer—all within a compact 14-terminal LCC package measuring just 6 mm × 5.6 mm × 2.05 mm.
Key differentiators of the ADXL357BEZ include its industry-leading noise density of 80 µg/√Hz, which enables detection of extremely small acceleration changes essential for seismology and structural health monitoring. The device offers three selectable full-scale ranges: ±10g at 51,200 LSB/g, ±20g at 25,600 LSB/g, and ±40g at 12,800 LSB/g. With an adjustable output data rate from 4000 Hz down to 3.906 Hz, designers can optimize the bandwidth-to-noise tradeoff for their specific application. Internal LDO regulators accept a supply voltage from 2.25 V to 3.6 V, simplifying power supply design in multi-voltage systems.
ADXL357BEZ PCB Footprint and Package Outline — 14-Terminal LCC (6 mm × 5.6 mm) (Source: Analog Devices Datasheet)
2. Specifications and Parameter Table
| Parameter | Value |
|---|---|
| Manufacturer | Analog Devices (ADI) |
| Sensor Type | 3-Axis MEMS Accelerometer (Digital Output) |
| Measurement Range | ±10g / ±20g / ±40g (selectable) |
| Sensitivity | 51,200 LSB/g (±10g) / 25,600 LSB/g (±20g) / 12,800 LSB/g (±40g) |
| Noise Density | 80 µg/√Hz (all axes) |
| 0g Offset Drift | 0.75 mg/°C maximum (all axes) |
| ADC Resolution | 20-bit sigma-delta |
| Output Data Rate (ODR) | 3.906 Hz to 4000 Hz (programmable) |
| Digital Interface | SPI (4-wire) and I²C |
| Supply Voltage (VSUPPLY) | 2.25 V to 3.6 V |
| Current Consumption | 200 µA (measurement mode) / 21 µA (standby) |
| Temperature Sensor | 12-bit SAR ADC (on-chip) |
| FIFO Buffer | 96 samples (stream, triggered, and oldest-saved modes) |
| Interrupt Outputs | INT1, INT2, DRDY (data ready) |
| Package | 14-Terminal LCC (6 mm × 5.6 mm × 2.05 mm) |
| Weight | 0.26 g |
| Operating Temperature | −40°C to +125°C |
| RoHS Compliance | RoHS3 Compliant, MSL 1 (Unlimited) |
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Check ADXL357BEZ Stock3. Architecture, Pinout, and Application Circuit
Internally, the ADXL357 integrates a 3-axis MEMS sensing element that detects acceleration along the X, Y, and Z axes via differential capacitance measurement. Each axis output passes through a dedicated analog anti-aliasing filter before digitization by the 20-bit sigma-delta ADC. A programmable digital low-pass filter further conditions the data, with configurable cutoff frequencies tied to the selected output data rate. The 96-sample FIFO buffer supports three operating modes—stream, triggered, and oldest-saved—enabling efficient data collection without continuous microcontroller polling.
The ADXL357BEZ features two interrupt pins (INT1, INT2) and a dedicated data-ready (DRDY) output for real-time event signaling. The serial interface supports 4-wire SPI at clock rates up to 10 MHz and I²C at standard and fast modes (up to 400 kHz). The 14-terminal LCC package includes dedicated pins for VSUPPLY, VDDIO (digital I/O voltage), V1P8ANA and V1P8DIG (internal 1.8 V regulator outputs), and separate analog and digital ground connections to minimize noise coupling.
For the typical application circuit, Analog Devices recommends applying power to VDDIO first, followed by VSUPPLY approximately 10 µs later. Decoupling capacitors of 0.1 µF and 1 µF should be placed close to VSUPPLY, VDDIO, V1P8ANA, and V1P8DIG pins. The internal LDO regulators generate the 1.8 V power rails, so the V1P8ANA and V1P8DIG pins should each have a 1 µF bypass capacitor to ground.
ADXL357BEZ Typical Application Circuit — SPI/I²C Interface with Decoupling Network (Source: Analog Devices Datasheet)
4. Video: MEMS Accelerometer Technology
This video demonstrates how MEMS accelerometers like the ADXL357 family work for orientation tracking and vibration measurement. Topics covered include sensor interfacing via SPI/I²C, data acquisition techniques, and real-world applications in tilt sensing and condition monitoring systems—directly relevant to designs using the ADXL357BEZ.
5. Equivalents, Cross-Reference, and Lifecycle
The ADXL357BEZ carries an Active production status from Analog Devices with no announced end-of-life date. The device is available in tray packaging, with reel variants offered as ADXL357BEZ-RL and ADXL357BEZ-RL7. For designs requiring different specifications or alternative sources, engineers should consider:
- ADXL355BEZ — A lower-range sibling in the same family supporting ±2g, ±4g, and ±8g ranges with even lower noise density (25 µg/√Hz). Pin-compatible with the ADXL357 and ideal for precision tilt and seismic applications requiring sub-g resolution.
- ADXL356BEZ — The analog-output variant of the ADXL357, offering the same ±10g/±20g/±40g ranges but with voltage output instead of digital interface. Suitable for systems requiring direct analog signal processing or interfacing with external high-resolution ADCs.
- ADXL354BEZ — The analog-output counterpart to the ADXL355, supporting ±2g/±4g/±8g ranges with analog voltage output. Preferred for ultra-precision tilt measurements in seismology and geophysical exploration.
- ICM-42688-P — A 6-axis IMU from TDK InvenSense combining accelerometer and gyroscope, offering an alternative for applications requiring rotational rate sensing alongside acceleration measurement.
When selecting an alternative, verify that the noise density, offset drift, and bandwidth specifications meet your application’s accuracy requirements. Check ADXL357BEZ Inventory & Pricing at WWDParts for current lead times and stock availability.
6. Frequently Asked Questions (FAQ)
Q1: What is the ADXL357BEZ, and what applications is it designed for?
The ADXL357BEZ is a low-noise, low-drift, low-power 3-axis digital MEMS accelerometer from Analog Devices, packaged in a 14-terminal LCC. It is designed for precision motion sensing applications including inertial measurement units (IMUs), altitude and heading reference systems (AHRS), platform stabilization, structural health monitoring, seismic imaging, tilt sensing, robotics, and industrial condition monitoring. Its ultralow noise density of 80 µg/√Hz and minimal offset drift make it suitable for applications where long-term measurement stability is critical.
Q2: How do I select the measurement range on the ADXL357?
The measurement range is configured via the RANGE register (address 0x2C). Write 0x01 for ±10g (default), 0x02 for ±20g, or 0x03 for ±40g. The sensitivity scales accordingly: 51,200 LSB/g at ±10g, 25,600 LSB/g at ±20g, and 12,800 LSB/g at ±40g. Range selection can be changed during operation, but Analog Devices recommends allowing at least four output data periods for the digital filter to settle after a range change before reading acceleration data.
Q3: What are the differences between the ADXL357 and ADXL355?
Both devices share the same 14-terminal LCC package and register interface, but they target different acceleration ranges. The ADXL355 supports ±2g, ±4g, and ±8g with a noise density of 25 µg/√Hz, making it more suited to ultra-precision tilt and seismic sensing. The ADXL357 supports ±10g, ±20g, and ±40g with 80 µg/√Hz noise density, targeting higher-g applications such as vibration analysis, condition monitoring, and robotics. The devices are pin-compatible and share the same driver software, so migrating between them requires only a register configuration change.
Q4: What power supply decoupling is recommended for the ADXL357BEZ?
Analog Devices recommends placing a 0.1 µF ceramic capacitor and a 1 µF ceramic capacitor in parallel, as close as possible to the VSUPPLY and VDDIO pins. The internal 1.8 V regulator outputs (V1P8ANA and V1P8DIG) each require a 1 µF bypass capacitor to ground. All ground pins (including the exposed pad, if applicable) should connect to a solid ground plane with short, low-impedance traces. The recommended power-up sequence is to apply VDDIO first, then VSUPPLY approximately 10 µs later to ensure proper initialization of the internal regulators.
Q5: How does the FIFO buffer work on the ADXL357, and when should I use it?
The ADXL357 includes a 96-sample FIFO buffer that supports three modes: stream mode (continuously overwrites oldest data), triggered mode (captures data around a trigger event), and oldest-saved mode (stops when full). The FIFO stores X, Y, Z acceleration and temperature samples, reducing the need for high-frequency microcontroller polling. Use stream mode for continuous vibration monitoring, triggered mode for event capture in impact detection, and oldest-saved mode for single-burst data acquisition. A FIFO watermark interrupt can be configured to signal the host when a programmable number of samples are available.
Q6: Can the ADXL357BEZ operate in both SPI and I²C modes, and how do I select the interface?
Yes. Interface selection is determined by the state of the MISO/ASEL pin at power-up. When MISO/ASEL is left floating or driven high, the device operates in SPI mode supporting clock rates up to 10 MHz. When MISO/ASEL is connected to GND or VSUPPLY, the device enters I²C mode with the address determined by the ASEL pin state (0x1D or 0x53). In SPI mode, the CS pin must be held low during transactions. In I²C mode, standard mode (100 kHz) and fast mode (400 kHz) are supported. Note that SPI mode offers higher throughput and is recommended for applications requiring maximum data rates.
For more MEMS accelerometer and sensor options, browse our Accelerometer catalog or explore our full semiconductor inventory. See also our guide on the latest sensor technology trends.
Alan Carter, Senior Hardware Engineer
Alan has over 15 years of experience in embedded systems design, specializing in MEMS sensor integration, precision measurement systems, and global semiconductor supply chain management. He frequently contributes technical teardowns and architecture comparisons.
