A High-Precision Fully Integrated Hall-Effect Angle Sensor with 0.087° Noise Floor in 0.35 μm CMOS Technology.

Area of Science:

• Electrical Engineering
• Sensor Technology
• Solid-State Physics

Background:

• Hall-effect sensors are widely used in magnetic-field measurement applications like current sensing and position detection.
• Standard CMOS compatibility makes silicon-based Hall elements attractive.
• Inherent offset and temperature drift in silicon Hall elements limit high-precision measurements.

Purpose of the Study:

• To present a fully integrated angle sensor chip designed to overcome the precision limitations of traditional Hall-effect sensors.
• To enable high-accuracy absolute angular encoding over a full 0-360° range.

Main Methods:

• Implementation of a novel sensor architecture in a 0.35 μm CMOS process.
• Integration of four cross-shaped Hall elements in an orthogonal array.
• Utilisation of a non-contact Hall-permanent magnet configuration.

Main Results:

• Demonstration of an absolute angular encoding capability across a full 0-360° range.
• Experimental characterisation revealing a low noise floor of 0.087° (3σ).

Conclusions:

• The proposed sensor architecture effectively addresses the challenges of offset and temperature drift in Hall-effect sensors.
• The developed chip validates the effectiveness of the architecture for high-accuracy angular measurement applications.