ADIS16495 inertial sensing unit

The ADIS16495 is a tactical-grade MEMS inertial measurement unit (IMU) from Analog Devices that combines a triaxial gyroscope and a triaxial accelerometer in one aluminum package, intended for navigation, guidance and stabilization on unmanned aircraft and other precision platforms.

The unit reports angular rate and linear acceleration on three axes each, and also provides delta angle and delta velocity outputs that an attitude or navigation filter in the host can integrate directly. The gyroscope range is selectable between +/-125 degrees per second, +/-450 degrees per second and +/-2000 degrees per second, so the same part can serve a slow, heavily damped gimbal as well as an agile airframe. The accelerometer measures up to +/-8 g.

For an integrator, the stability figures matter most. Gyroscope in-run bias stability is 0.8 degrees per hour and angular random walk is 0.09 degrees per root hour, which sets how slowly heading and attitude drift when GNSS or vision corrections are unavailable. Accelerometer in-run bias stability is 3.2 micrograms, which limits the error in velocity and tilt estimates over time. Sensitivity, bias and axial alignment are calibrated at the factory over a temperature range of -40 degrees C to +85 degrees C, with axis-to-axis misalignment of +/-0.05 degrees, so little extra calibration is needed in the airframe. Configurable FIR filters, automatic and manual bias correction, and an on-demand self-test of the inertial sensors are available through the register set.

Integration is through an SPI-compatible digital interface with a programmable register structure. The unit has digital inputs and outputs for a data-ready signal and for an external clock, and its sample clock can run internally, from an external source or scaled, which lets a flight computer lock IMU sampling to its own timing. It runs from a single supply of 3.0 V to 3.6 V. The package measures approximately 47 x 44 x 14 mm, uses a standard connector, and shares its footprint and connector with several earlier devices of the same family, which allows a drop-in upgrade on existing designs.

The operating temperature range is -40 degrees C to +105 degrees C and the package survives mechanical shock of 1500 g, which suits mounting close to motors, payload electronics and airframe structure on vehicles that see wide thermal and vibration loads.

Typical applications are guidance, navigation and control, avionics and unmanned vehicles, precision instrumentation and stabilization, and autonomous machines and robotics. Buyers comparing IMUs for UAS flight controllers, inertial navigation systems, gimbals and stabilized payloads will find the combination of tactical-grade stability, factory calibration and a compact SPI-based package suited to those roles.