A33230 Hall Effect and CT310 TMR Angle Sensors

Introduction to the sensors

1. A33230 3D Hall-Effect Sensor IC

The A33230 is a 3D Hall-effect sensor designed for precise position sensing of magnetic targets. It incorporates both vertical and planar Hall-effect elements, enabling it to detect magnetic fields in three axes (XY, XZ, or YZ) with 90° phase separation. This sensor provides sine and cosine outputs, making it suitable for angular measurement applications. It operates on a 5V supply, has ratiometric outputs, and is automotive-qualified (AEC-Q100 Grade 0), making it ideal for high-precision motion sensing applications.

1. CT310 2D TMR Angle Sensor 

The CT310 is a 2D angle sensor that utilizes Allegro’s XtremeSense™ tunnel magnetoresistance (TMR) technology. It features a dual full-bridge configuration, providing highly accurate sine and cosine differential outputs. This sensor operates within a magnetic field range of 250 to 900 G and offers an angle error of less than 0.60° after one-time compensation. It supports a supply voltage of 1.0 to 5.5V and is AEC-Q100 Grade 1 qualified, making it suitable for precise angular measurement applications, including rotary sensing in BLDC motors.

Introduction to the Demo Board

• The CT310 TMR and A33230 Hall Effect Angle sensors, which are placed on top of PCB.
• The stepper motor’s shaft is fitted with a diametric magnet to produce angular movement.
•  The stepper motor is driven by an AMT49700 stepper motor driver.
• The Stepper motor is also fitted with an AMT203V absolute encoder.
• The sine and cosine output is accessible from the 40 pin on-board connector.

Rotor Position Sensor Evaluation Lab’s Overview

• Evaluating the Sweep Test for Sensor Accuracy

A sweep test helps compare the measured angle with the reference angle to assess sensor accuracy and response to motor position changes. Sine and cosine waveforms can be recorded and analyzed.

• Assessing Sensor Consistency in Repeated Rotations 

Ensuring the sensor provides consistent angle readings across multiple 360-degree rotations is crucial for reliable motor control. Checking for repeatability in readings helps identify potential calibration issues or external factors affecting accuracy.

• Defining a Custom Zero Reference for Angle Measurement

Users can set any mechanical angle as the zero reference, allowing angle measurements to start from that point. This feature helps align the motor’s position for applications like robotics, servo motors, and position control systems.