ALS31300: 3-D Linear Hall-Effect Sensor with I²C Output and Advanced Low Power Management

The ALS31300 three-axis linear Hall-effect sensor IC provides a 12-bit digital value corresponding to the magnetic field measured in each of the X, Y, and Z axes. The ALS31300 is preconfigured for use in 3D sensing applications for head-on linear motion, slide-by position sensing, and rotation angle measurements. The ALS31300 is also offered in joystick mode, including a low gain option for the Z axis channel. This feature enables the use of a back-bias magnet to provide return-to-zero force instead of traditional spring-based solutions.

Three different factory-programmed sensitivity ranges are available: ±500 G, ±1000 G, and ±2000 G.

The I²C address of the ALS31300 can be set either by external resistors (16 unique addresses) or programmed into EEPROM via I²C (127 unique addresses), allowing for multiple devices on the same bus. The ALS31300 also includes 78 bits of user EEPROM.

The ALS31300 enables robust joystick design, replacing potentiometer based joystick modules. Magnetic joysticks can be low-profile, and enable low system power for battery-powered applications, and support joystick wake-on motion. With the addition of a back-bias magnet the ALS31300 enables magnetic return to zero, or removable joysticks.

Power management of the ALS31300 is highly configurable, allowing for system-level optimization of supply current and performance. Sleep mode consumes just 14 nA (typical), making the ALS31300 well suited for portable, battery-operated applications.

The ALS31300 is supplied in a 3 mm × 3 mm × 0.8 mm, 10-contact DFN package (“EJ”). This small footprint package is lead (Pb) free, with 100 % matte-tin lead-frame plating.

• X- and Y-axis sensing of joystick position
• Z-axis sensing of “crouch” or push button motion
• Capable of operating with back-bias magnets for joystick return-to-zero
• Ideal for battery-powered, low-voltage applications
  • 2.65 to 3.5 V single supply operation
  • 1 MHz I²C compatibility down to 1.8 V
  • 14 nA (typ) Sleep I_CC
  •  12 μA to 2 mA I_CC (typ) in low-power duty cycle mode
• Industry standard I²C interface for easy system integration
  • Up to 1 MHz (Fast Mode+) I²C communication
  • 16 selectable addresses via external resistor divider
  • 127 available address configurable via EEPROM
• On-chip EEPROM
  • Stores factory- and user-configured settings
  • 78 bits of user EEPROM for additional storage
  • On-chip charge pump for easy programming
• Flexible 12-bit ADC with 10-bit ENOB (Effective Number of Bits)
• 1% (typ) accurate factory-trimmed sensitivity options (±500 G, ±1000 G, and ±2000 G full-scale input)
• Integrated temperature sensor
• Wide ambient temperature range: –40°C to 85°C
• 10-contact 3 mm × 3 mm × 0.8 mm DFN package for implementation in low-profile, high-density PCB designs and space-constrained applications