MPU-6000

The MPU-6000 is a 6-axis Motion Processing Unit (MPU) manufactured by InvenSense (acquired by TDK, now TDK InvenSense). It was the world’s first integrated 6-axis motion sensor, combining a 3-axis MEMS gyroscope and a 3-axis MEMS accelerometer on a single silicon die, along with a Digital Motion Processor (DMP) that offloads complex sensor fusion algorithms from the host processor. The MPU-6000 represents the second generation of InvenSense’s motion processing technology, building on the success of the MPU-30X0 single gyroscope family. The ‘MPU’ stands for Motion Processing Unit, distinguishing it from simple IMU (Inertial Measurement Unit) devices by its integrated motion processing capability. The ‘6000’ series number indicates 6-axis integration. The MPU-6000 is unique in the 60X0 family for supporting both I²C and SPI serial interfaces (the MPU-6050 variant supports only I²C), making it the preferred choice for applications requiring higher data throughput or simpler SPI-based communication. The gyroscope features a vibrating MEMS structure that uses the Coriolis effect to detect angular rate, with user-programmable full-scale ranges of ±250, ±500, ±1000, or ±2000 degrees per second. Each axis has a dedicated 16-bit sigma-delta ADC for high-resolution measurement. The accelerometer uses a capacitive MEMS proof-mass structure with three independent axes, offering full-scale ranges of ±2g, ±4g, ±8g, or ±16g. Like the gyro, each accelerometer axis has its own 16-bit ADC. A standout feature is the Digital Motion Processor (DMP), a dedicated hardware engine that performs 9-axis sensor fusion (when paired with an external magnetometer via the auxiliary I²C bus), gesture recognition, and other motion processing algorithms. This offloads the host processor from intensive computation and reduces system power consumption. A 1024-byte FIFO buffer allows the host processor to read sensor data in bursts and then enter low-power modes while the MPU continues collecting data. The device operates from a single 2.375V to 3.46V supply and comes in a compact 24-pin QFN package measuring just 4×4×0.9mm.

The MPU-6000 operates as an integrated 6-axis motion processing system combining MEMS sensing with digital signal processing: 1) 3-Axis MEMS Gyroscope: – Operating Principle: Vibrating tuning fork structures driven at resonance detect angular rate using the Coriolis effect. When the device rotates, the vibrating proof masses experience a Coriolis force perpendicular to both the vibration direction and the rotation axis, causing a measurable displacement. – Sensing: Capacitive sensing detects the Coriolis-induced displacement. The signal is amplified, demodulated, and filtered to produce a voltage proportional to angular rate. – ADC: Each axis has a dedicated 16-bit sigma-delta ADC that digitizes the rate signal. Sampling rate is programmable from 3.9Hz to 8kHz. – Full Scale: User-programmable ±250, ±500, ±1000, ±2000 °/s (dps). 2) 3-Axis MEMS Accelerometer: – Operating Principle: Each axis has a suspended proof mass that deflects under acceleration. The deflection changes the capacitance between the proof mass and fixed electrodes, with differential sensing rejecting common-mode interference. – Architecture: The capacitive MEMS structure is designed for low noise and low cross-axis sensitivity. Each axis is independent and factory-calibrated. – ADC: Each channel uses a 16-bit sigma-delta ADC. – Full Scale: User-programmable ±2g, ±4g, ±8g, ±16g. 3) Digital Motion Processor (DMP): – A dedicated hardware accelerator that processes sensor data independently of the host CPU. – Performs 9-axis MotionFusion when combined with an external magnetometer (connected via auxiliary I²C). – Handles gesture recognition, tap detection, orientation detection, pedometer, and other motion-based algorithms. – Outputs processed quaternion or Euler angle data, reducing host processing load. 4) FIFO Buffer: – 1024-byte first-in-first-out buffer stores sensor samples (gyro, accel, temperature, external sensor data). – Allows the host processor to read data in bursts and then sleep, minimizing power consumption. – Programmable watermark interrupt triggers when FIFO reaches a threshold. 5) Temperature Sensor: – On-chip temperature sensor with digital output, used for temperature compensation of gyro and accelerometer biases. 6) Clock System: – Internal 8MHz on-chip oscillator with ±1% accuracy over temperature. – Optional external clock input (32.768kHz or 19.2MHz) for higher accuracy applications. 7) Serial Interfaces: – Primary I²C interface: Up to 400kHz, used for register configuration and data reads. – Primary SPI interface: Up to 20MHz (for sensor data reads), 1MHz for all registers. SPI is a key advantage of MPU-6000 over MPU-6050. – Auxiliary I²C master: Connects to external sensors (e.g., magnetometer like AK8975). Supports pass-through mode for direct host access. 8) Interrupt System: – Programmable interrupt outputs for data ready, FIFO watermark, FIFO overflow, motion detection, zero-motion detection, free-fall detection, and tap detection. 9) Power Management: – Multiple power modes: full operation, gyro-only, accel-only low power, sleep, and standby. – Low-power accelerometer mode with 1.25-40Hz sampling for motion wakeup applications.

QFN-24 package, 4.0 × 4.0 × 0.9 mm. Pin 1 is marked by a dot on the package top.

• Smartphone and tablet motion sensing (screen rotation, gesture control)
• Gaming controllers (Wii-like motion remotes, VR controllers)
• Wearable fitness trackers and smartwatches
• Drone and UAV flight stabilization and navigation
• Self-balancing robots and inverted pendulum systems
• Virtual reality and augmented reality head tracking
• Pedestrian dead reckoning (PDR) and indoor navigation
• Industrial vibration monitoring and predictive maintenance