MT6835 Magnetic Rotary Encoder Module

Overview

The MT6835 magnetic encoder module is a high-precision, non-contact rotary angle position sensor based on the MT6835 magnetic encoder IC. It provides 14-bit absolute angle measurement by detecting the magnetic field of a paired diametrically magnetized magnet, delivering accurate and reliable position feedback for rotating systems. This module integrates multiple output interfaces including SPI, ABZ incremental, UVW commutation, and PWM / analog output, offering flexible compatibility with various motor controllers, MCU platforms and industrial control systems. Compact PCB design with pre-drilled mounting holes facilitates quick integration into servo motors, robotic joints, gimbal systems and industrial automation equipment. Widely adopted by engineers, research laboratories and equipment manufacturers across Europe.

Working Principle

The MT6835 operates on the Hall-effect magnetic sensing principle:

1. Magnetic Field Detection: A diametrically magnetized permanent magnet rotates above the chip. The MT6835 integrates an array of Hall-effect sensors that detect the horizontal components of the magnetic field in both X and Y axes.
2. Signal Conditioning & ADC: The analog Hall signals are amplified, filtered and converted into digital values by on-chip high-resolution ADCs.
3. Angle Calculation: An internal DSP core processes the X/Y magnetic field components using the CORDIC algorithm to compute the absolute angular position of the magnet, achieving 14-bit (16384 counts per revolution) resolution.
4. Multi-Interface Output: The calculated angle data is output through multiple configurable interfaces:
   • SPI Interface: For reading absolute angle data and configuring chip parameters
   • ABZ Incremental Output: Standard quadrature encoder signals with index pulse, compatible with conventional encoder inputs
   • UVW Output: For brushless DC motor commutation, replacing traditional Hall sensors
   • PWM / Analog Output: Proportional pulse-width or voltage signal representing angular position
5. On-the-Fly Calibration: The CAL_EN pin enables zero-position calibration and parameter configuration, allowing users to set the zero point and adjust output parameters without physical alignment.

Key Features

1. ✅ High-resolution 14-bit absolute angle measurement (16384 counts per revolution)
2. ✅ Non-contact magnetic sensing technology — no mechanical wear, long service life
3. ✅ Multiple output interfaces: SPI, ABZ incremental, UVW, PWM / analog
4. ✅ Compatible with 3.3V and 5V supply voltage
5. ✅ Includes matching diametrically magnetized magnet
6. ✅ CAL_EN pin for zero-point calibration and parameter configuration
7. ✅ Compact PCB footprint with four mounting holes for easy installation
8. ✅ High noise immunity, stable performance in industrial environments
9. ✅ Cost-effective alternative to optical encoders

Pin Description

• VCC: Power supply (3.3V / 5V)
• GND: Ground
• MISO / MOSI / SCK / CSN: SPI communication interface
• CAL_EN: Calibration enable / parameter configuration pin
• A / B / Z: ABZ incremental encoder output
• U / V / W: UVW motor commutation output
• OUT: PWM / analog output

Typical Applications

• Brushless DC (BLDC) motor and servo motor position feedback
• Robotic joint and actuator angle sensing
• Gimbal and pan-tilt position control
• Industrial automation rotary position detection
• Medical equipment precision angle measurement
• Automotive sensor and control systems
• University laboratory research and prototyping
• 3D printer and CNC machine axis position feedback

Important Notes

1. The magnet must be diametrically magnetized (N/S poles across the diameter) and centered above the chip for accurate measurement.
2. Maintain proper air gap between magnet and sensor surface — refer to datasheet for recommended distance range.
3. Avoid placing ferromagnetic materials near the sensing area, as they may distort the magnetic field and affect accuracy.
4. ABZ and UVW output parameters are configurable via SPI interface.