AXO315T | TDK‑Tronics (a TDK Group Company), High‑Temperature Closed‑Loop Single‑Axis MEMS Accelerometer

Brand: TDK‑Tronics (a TDK Group Company). High‑Temperature Closed‑Loop Single‑Axis MEMS Accelerometer. Developed for extreme high‑temperature and high‑vibration environments of oil‑gas Measurement‑While‑Drilling (MWD), as a replacement for quartz accelerometers.

 Overview

Single‑axis accelerometer with closed‑loop architecture, hermetic ceramic package and 24‑bit SPI digital output. Two sub‑models are available:

‑ AXO315T0: ‑30 ℃ ~ +150 ℃

‑ AXO315T1: ‑30 ℃ ~ +175 ℃ (maximum operating temperature 175 ℃)

Difference from standard AXO315: The standard AXO315 has a maximum temperature of +105 ℃. The AXO315T series features enhanced high‑temperature reliability and has been validated for over 1000 hours of continuous high‑temperature operation in down‑hole conditions.

 Key Specifications

‑ Measurement range: ±14 g

‑ Architecture: Closed‑loop MEMS; vibration rectification error: 20 µg/g² (approximately 10× better vibration immunity compared with open‑loop MEMS)

‑ Noise density: 10 µg/√Hz for T0; 20 µg/√Hz for T1 under high‑temperature conditions

‑ Full‑temperature residual bias error: T0 ≤ 0.8 mg; T1 ≤ 1.7 mg

‑ Bandwidth: 150 Hz; maximum data output rate: 2500 Hz; latency: 2 ms

‑ Non‑linearity: 80 ppm

‑ Power supply: 5 V (4.75‑5.25 V); I/O supply: 5 V

‑ Interface: 24‑bit SPI digital output; built‑in power‑on and continuous BIST self‑diagnosis

‑ Package: 28‑pin J‑LEAD hermetic ceramic SMD; dimensions 12.45 × 12.45 × 5.5 mm

‑ Vibration resistance: 20 g RMS random vibration; shock survival: 2000 g

‑ Lifetime: > 1000 hours continuous operation for T0 at 165 ℃ and T1 at 175 ℃

‑ Compliance: RoHS, REACH; not subject to dual‑use export‑control regulations

## Main Functions

1. High‑precision single‑axis measurement of acceleration and gravity components for tilt‑angle calculation.

2. Closed‑loop architecture suppresses vibration rectification error under heavy drilling‑induced vibration to maintain stable tilt data without drift.

3. 24‑bit SPI digital output; no external ADC required, simplifying down‑hole circuitry.

4. Built‑in continuous hardware self‑diagnosis for real‑time fault reporting.

5. Factory full‑temperature calibration reduces customer system‑level compensation efforts.

Application Scope

1. Oil‑gas Measurement‑While‑Drilling (MWD, primary application): Down‑hole probe for directional drilling, high‑temperature borehole tilt and inclination measurement, substitute for high‑cost quartz accelerometers.

2. Geological exploration, down‑hole tools and deep‑drilling equipment.

3. High‑temperature industrial IMU inertial measurement units; multi‑AXO315T assemblies for multi‑axis inertial systems.

4. Geothermal equipment and deep‑well monitoring instruments.

5. Aerospace and special‑defense high‑temperature attitude measurement (tactical‑grade inertial applications).

 Model Comparison

‑ AXO315: ‑55 ℃ ~ +105 ℃, standard tactical‑grade IMU, not suitable for down‑hole high‑temperature service

‑ AXO315T0: ‑30 ℃ ~ +150 ℃, standard down‑hole variant
‑ AXO315T1: ‑30 ℃ ~ +175 ℃, ultra‑high‑temperature down‑hole variant