MPU9250 9-axis Digital Motion Processor

MPU-9250 is a multi-chip module (MCM) consisting of two dies integrated into a single QFN package. One die houses the 3-Axis gyroscope and the 3-Axis accelerometer. The other die houses the AK8963 3-Axis magnetometer from Asahi Kasei Microdevices Corporation. Hence, the MPU-9250 is a 9-axis motion tracking device that combines a 3-axis gyroscope, 3-axis accelerometer, 3-axis magnetometer, and a Digital Motion Processor.

 

Its dedicated I2C sensor bus, the MPU-9250directly provides complete 9-axis Motion Fusion output. For requiring faster communications, the sensor and interrupt registers may be read using SPI as well.

 

Pin Description of MPU9250 9-axis MotionTracking Digital Motion Processor

Pin Number	Pin Name	Descriptions
1	RESV	Reserved. Connect to VDDIO.
7	AUX_CL	I2C Master serial clock, for connecting to external sensors
8	VDDIO	Digital I/O supply voltage
9	AD0 /SDO	I2C Slave Address LSB (AD0); SPI serial data output (SDO)
10	REGOUT	Regulator filter capacitor connection
11	FSYNC	Frame synchronization digital input. Connect to GND if unused
12	INT	Interrupt digital output (totem pole or open-drain)
13	VDD	Power supply voltage and Digital I/O supply voltage
18	GND	Power supply ground
19	RESV	Reserved. Do not connect
20	RESV	Reserved. Connect to GND
21	AUX_DA	I2C master serial data, for connecting to external sensors
22	nCS	Chip select (SPI mode only)
23	SCL / SCLK	I2C serial clock (SCL); SPI serial clock (SCLK)
24	SDA / SDI	I2C serial data (SDA); SPI serial data input (SDI)
2-6, 14-17	NC	Not internally connected. May be used for PCB trace routing.

 

The pinout is shown in the below image-

 

 

Features and Specification of MPU9250 9-axis Digital Motion Processor

1. 3-axis Gyroscope Features

• Digital-output X-, Y-, and Z-Axis angular rate sensors (gyroscopes) with a user-programmable full-scale range of ±250, ±500, ±1000, and ±2000°/secand integrated 16-bit ADCs
• Digitally-programmable low-pass filter
• Gyroscope operating current: 3.2mA
• Sleep mode current: 8μA
• Factory calibrated sensitivity scale factor
• Self-test

 

2. 3-axis Accelerometer Features

• Digital-output triple-axis accelerometer with a programmable full-scale range of ±2g, ±4g, ±8gand ±16gand integrated 16-bit ADCs
• Accelerometer normal operating current: 450μA
• Low power accelerometer mode current: 8.4μA at 0.98Hz, 19.8μA at 31.25Hz
• Sleep mode current: 8μA
• User-programmable interrupts
• Wake-on-motion interrupt for low power operation of applications processor
• Self-test

 

3. 3-axis Magnetometer Features

• 3-axis silicon monolithic Hall-effect magnetic sensor with magnetic concentrator
• Wide dynamic measurement range and high resolution with lower current consumption.
• Output data resolution of 14 bit (0.6μT/LSB)
• Full-scale measurement range is ±4800μT
• Magnetometer normal operating current: 280μA at 8Hz repetition rate
• Self-test function with the internal magnetic source to confirm magnetic sensor operation on end products

 

4. Additional Features

• Auxiliarymaster I2C bus for reading data from external sensors(e.g. pressure sensor)
• Digital-output temperature sensor
• VDD supply voltage range of 2.4–3.6V
• VDDIO reference voltage for auxiliary I2C devices
• Smallest and thinnest QFNpackage for portable devices:3x3x1mm
• Minimal Cross-axis sensitivity between the accelerometer, gyroscope and magnetometer axes
• 512byte FIFO buffer enables the applications processor to read the data in bursts
• 10,000gshock tolerant
• 400kHz Fast Mode I2C for communicating with all registers
• 1MHz SPI serial interface for communicating with all registers
• 20MHz SPI serial interface for reading sensor and interrupt registers
• MEMS structure hermetically sealed and bonded at the wafer level

 

Note: Complete technical details can be found in the MPU9250 Datasheet linked at the bottom of this page.

 

MPU9250 9-axis Digital Motion Processor - Overview

 

The InvenSense MPU9250 9-axis Digital Motion Processor is a combined processor of the 3-axis gyroscope, 3-axis accelerometer, and the 3-axis Magnetometer. This IC is also designed to interface with multiple non-inertial digital sensors, such as pressure sensors, on its auxiliary I2C port.

 

MPU-9250 features three 16-bit analog-to-digital converters (ADCs) for digitizing the gyroscope outputs, three 16-bit ADCs for digitizing the accelerometer outputs, and three 16-bit ADCs for digitizing the magnetometer outputs. For precision tracking of both fast and slow motions, the parts feature a user-programmable gyroscope full-scale range of ±250, ±500, ±1000, and ±2000°/sec (DPS), a user-programmable accelerometer full-scale range of ±2g, ±4g, ±8g, and ±16g, and a magnetometer full-scale range of ±4800μT.

 

The microcontroller can communicate with this IC using either I2C or SPI serial bus interface. As per the application required, the user can configure the communication interface for 20MHz SPI mode for fast communication but default communication speed 400kHz for I2C and 1MHz for SPI.

 

Interfacing Diagram

 

The interfacing is quite easy using an I2C bus. The 9250 IC can easily be interfaced with any microcontroller having an I2C interface. However, this IC can also be interfaced using SPI protocol.

If the targeted microcontroller does not use I2C pull up resistors, R1 and R2 can be added.

 

Applications of MPU9250 9-axis Digital Motion Processor

• Location-based services, points of interest, and dead reckoning
• Handset and portable gaming
• Motion-based game controllers
• 3D remote controls for Internet-connected DTVs and set-top boxes, 3D mice
• Wearable sensors for health, fitness, and sports

 

2D and 3D Model