BMA400 — 3-axis Ultra-Low-Power Accelerometer

{
  "schema_version": 1,
  "type": "component",
  "slug": "bma400",
  "title": "BMA400 — 3-axis Ultra-Low-Power Accelerometer",
  "brief": "Bosch Sensortec BMA400. 12-bit triaxial accelerometer, ±2g/±4g/±8g/±16g, <14.5µA normal mode. Step counter, activity recognition, tap detection, 1KB FIFO, SPI/I²C. LGA-12 2×2×0.95mm.",
  "version": "1.0.0",
  "tags": [],
  "license": "MIT",
  "sample_prompts": [
    {
      "prompt": "Show me the BMA400 datasheet",
      "label": "View datasheet"
    },
    {
      "prompt": "What's the current consumption of the BMA400?",
      "label": "Check power"
    },
    {
      "prompt": "What interrupts does the BMA400 support?",
      "label": "Interrupt features"
    },
    {
      "prompt": "Give me the BMA400 pin configuration",
      "label": "Pinout"
    },
    {
      "prompt": "What's the step-counter current draw on the BMA400?",
      "label": "Step counter"
    },
    {
      "prompt": "Compare the BMA400 with other Bosch accelerometers",
      "label": "Compare"
    }
  ],
  "component": {
    "mpn": "BMA400 — 3-axis Ultra-Low-Power Accelerometer",
    "manufacturer": "Bosch Sensortec",
    "package": "",
    "pin_count": null,
    "category": "Accelerometer",
    "subcategory": "",
    "body_size": null,
    "parts": {},
    "distributor_links": {}
  },
  "readme": "**Source:** [Bosch Sensortec BMA400 Data Sheet (BST-BMA400-DS000-14)](https://www.bosch-sensortec.com/media/boschsensortec/downloads/datasheets/bst-bma400-ds000.pdf)\n**Manufacturer:** Bosch Sensortec\n**Part Number:** BMA400\n**Document:** BST-BMA400-DS000-14 — Rev 2.3, July 2025\n\n## Description\n\nThe BMA400 is a 12-bit, digital, triaxial acceleration sensor with smart on-chip motion and position-triggered interrupt features. It is Bosch Sensortec's first ultra-low-power accelerometer, offering full programmability with an advanced set of integrated motion-detection algorithms while keeping supply current under 14.5 µA at the highest performance mode. A dedicated step counter supports extended battery life in wearables at a current consumption of only 4 µA.\n\nThe sensor targets coin-cell-powered IoT products, smartwatches, fitness trackers, and door/window alarm devices, where always-on motion detection is needed without draining the battery.\n\n## Key Specifications\n\n| Parameter | Value |\n| --- | --- |\n| Resolution | 12 bit |\n| Acceleration Ranges | ±2g / ±4g / ±8g / ±16g |\n| Output Data Rate | 12.5 Hz – 800 Hz |\n| Current (normal mode) | < 14.5 µA |\n| Current (step counter only) | 4 µA |\n| Current (sleep mode) | 160 nA |\n| Current (low-power mode, 25 Hz ODR) | 850 nA |\n| Supply Voltage V<sub>DD</sub> | 1.72 – 3.6 V |\n| Supply Voltage V<sub>DDIO</sub> | 1.2 – 3.6 V |\n| Operating Temperature | −40 °C to +85 °C |\n| Package | LGA-12, 2.0 × 2.0 × 0.95 mm |\n| FIFO Depth | 1024 bytes |\n| Digital Interface | I²C, SPI (4-wire and 3-wire) |\n| Interrupt Pins | 2 |\n\n## Features\n\n- Small LGA-12 package, footprint 2 mm × 2 mm, height 0.95 mm\n- Ultra-low-power operation — < 14.5 µA with highest performance\n- Programmable acceleration ranges (±2 g / ±4 g / ±8 g / ±16 g)\n- Low-pass filter bandwidth selectable at 0.48 × ODR\n- Output data rate up to 800 Hz\n- Integrated 1 KB FIFO with watermark and full interrupts\n- On-chip interrupt engine: auto-wakeup, auto-low-power, activity/in-activity\n- Step counter with 4 µA system current consumption\n- Activity recognition (walking, running, standing still)\n- Tap / double-tap detection\n- Orientation detection\n- SPI (4-wire, 3-wire), I²C, two interrupt pins\n- V<sub>DDIO</sub> range 1.2 V – 3.6 V\n- RoHS compliant, halogen-free\n\n## Pin Configuration\n\n| Pin | Name | Type | Description |\n| --- | --- | --- | --- |\n| 1 | SDO | Digital I/O | Serial data output in SPI mode; I²C address-select in I²C mode |\n| 2 | SDX | Digital I/O | SDA in I²C; SDI in 4-wire SPI; SDA in 3-wire SPI |\n| 3 | VDDIO | Supply | Digital I/O supply voltage (1.2 – 3.6 V) |\n| 4 | NC | — | Not connected |\n| 5 | INT1 | Digital I/O | Interrupt output 1 (default) |\n| 6 | INT2 | Digital I/O | Interrupt output 2 (default) |\n| 7 | VDD | Supply | Analog and digital supply (1.62 – 3.6 V) |\n| 8 | GNDIO | Ground | Ground for digital I/O domain |\n| 9 | GND | Ground | Analog and digital ground |\n| 10 | CSB | Digital In | Chip-select for SPI mode |\n| 11 | NC | — | Not connected |\n| 12 | SCX | Digital In | SCK in SPI mode; SCL in I²C mode |\n\n## Absolute Maximum Ratings\n\n| Parameter | Condition | Min | Max | Units |\n| --- | --- | --- | --- | --- |\n| Voltage at Supply Pin | V<sub>DD</sub> Pin | −0.3 | 4 | V |\n| Voltage at Supply Pin | V<sub>DDIO</sub> Pin | −0.3 | 4 | V |\n| Voltage at any Logic Pin | Non-Supply Pin | −0.3 | V<sub>DDIO</sub>+0.3, < 4 | V |\n| Passive Storage Temp. Range | ≤ 65 % rel. H. | −50 | +150 | °C |\n| Mechanical Shock | Duration ≤ 200 µs | — | 10 000 | g |\n| Mechanical Shock | Duration ≤ 1.0 ms | — | 2 000 | g |\n| Free fall | onto hard surfaces | — | 1.8 | m |\n| ESD | HBM, at any pin | — | 2 | kV |\n| ESD | CDM | — | 500 | V |\n| ESD | MM | — | 200 | V |\n\n> **Note.** Stress above these limits may cause damage to the device. Exceeding the specified electrical limits may affect reliability or cause malfunction.\n\n## Electrical Characteristics\n\n### Output Signal\n\n| Parameter | Symbol | Condition | Min | Typ | Max | Units |\n| --- | --- | --- | --- | --- | --- | --- |\n| Sensitivity | S<sub>2g</sub> | g<sub>FS2g</sub>, T<sub>A</sub>=25 °C | — | 1024 | — | LSB/g |\n| Sensitivity | S<sub>4g</sub> | g<sub>FS4g</sub>, T<sub>A</sub>=25 °C | — | 512 | — | LSB/g |\n| Sensitivity | S<sub>8g</sub> | g<sub>FS8g</sub>, T<sub>A</sub>=25 °C | — | 256 | — | LSB/g |\n| Sensitivity | S<sub>16g</sub> | g<sub>FS16g</sub>, T<sub>A</sub>=25 °C | — | 128 | — | LSB/g |\n| Sensitivity Temp. Drift | TCS | Nominal V<sub>DD</sub>/V<sub>DDIO</sub>, g<sub>FS4g</sub> | — | 0.025 | — | %/K |\n| Zero-g Offset | Off | Nominal V<sub>DD</sub>/V<sub>DDIO</sub>, g<sub>FS4g</sub> | — | 50 | — | mg |\n| Zero-g Offset Temp. Drift | TCO | Nominal V<sub>DD</sub>/V<sub>DDIO</sub>, g<sub>FS4g</sub> | — | 1 | — | mg/K |\n| Output Data Rate | ODR<sub>NORM</sub> | Normal mode | 12.5 | — | 800 | Hz |\n| Output Data Rate | ODR<sub>LPM</sub> | Low-power mode | — | 25 | — | Hz |\n| Bandwidth | BW<sub>NORM</sub> | 3 dB cutoff selectable in normal mode | 0.24 × ODR<sub>NORM</sub> | — | 0.48 × ODR<sub>NORM</sub> | Hz |\n| Nonlinearity | NL | Nominal V<sub>DD</sub>/V<sub>DDIO</sub> | — | 0.5 | — | %FS |\n| Output Noise Density | n<sub>RMS</sub> | Nominal V<sub>DD</sub>/V<sub>DDIO</sub>, OSR<3, X/Y-axis | — | 180 | — | µg/√Hz |\n| Output Noise Density | n<sub>RMS</sub> | Nominal V<sub>DD</sub>/V<sub>DDIO</sub>, OSR<3, Z-axis | — | 240 | — | µg/√Hz |\n\n### Mechanical Characteristics\n\n| Parameter | Symbol | Condition | Typ | Units |\n| --- | --- | --- | --- | --- |\n| Cross-Axis Sensitivity | S | relative contribution between any two axes | 2 | % |\n| Alignment Error | E<sub>A</sub> | relative to package outline | 0.5 | ° |\n\n### Current Consumption\n\n| Parameter | Symbol | Condition | Typ | Units |\n| --- | --- | --- | --- | --- |\n| Supply Current — Normal mode | I<sub>DD</sub> | V<sub>DD</sub>=1.8 V, OSR=3 | 14.5 | µA |\n| Supply Current — Normal mode | I<sub>DD</sub> | OSR=0 | 3.5 | µA |\n| Supply Current — Sleep mode | I<sub>DDsleep</sub> | V<sub>DD</sub>=1.8 V, 25 °C | 160 | nA |\n| Supply Current — Low-power mode | I<sub>DDlpf</sub> | V<sub>DD</sub>=1.8 V, 25 Hz ODR, OSR=0 | 850 | nA |\n| Wake-up Time | t<sub>w_up</sub> | From sleep to normal mode | 2 / ODR | ms |\n| Power-Up Time | t<sub>s_up</sub> | From device start | 1 | ms |\n\n## Communication Interface\n\n| Parameter | Default | Configurable |\n| --- | --- | --- |\n| Primary interface | I²C | Yes, SPI via register |\n| SPI modes | 4-wire | 4-wire / 3-wire |\n| I²C speed | Fast-mode 400 kHz | Standard / Fast / Fast+ |\n| SPI clock | up to 10 MHz | — |\n| Interrupt pins | 2 (INT1, INT2) | Mapping configurable |\n\n## Applications\n\n- Step counting for extended-battery-life wearables\n- Always-on motion detection in IoT devices and smart watches\n- Advanced system-level power management for mobile devices\n- Fitness and activity-tracking applications\n- Tap / double-tap input detection\n- Drop detection for warranty / transport logging\n- Window/door state sensing for climate-control and alarm systems\n- Battery-powered products operating from coin cells requiring < 1 µA average and auto-wakeup functionality\n",
  "author": {
    "id": "695820315b5f1e4db2fcf602",
    "name": "Kyle Bergstedt",
    "email": "[email protected]"
  },
  "visibility": {
    "public": true
  },
  "hero": null,
  "discovery_triggers": [],
  "discovery_pitch": null,
  "metadata": {},
  "created_at": "2026-05-28T05:36:52.632Z",
  "updated_at": "2026-05-28T05:36:52.632Z"
}