A Monolithic CMOS Magnetic Hall Sensor with High Sensitivity and Linearity Characteristics

Area of Science:

• Electrical Engineering
• Solid-State Physics
• Microelectronics

Background:

• Hall effect sensors are crucial for magnetic field measurement.
• Integrated Hall sensors require high sensitivity and low offset for reliable performance.
• Existing Hall sensor designs face challenges in achieving both high sensitivity and low offset.

Purpose of the Study:

• To present a fully integrated linear Hall sensor using 0.8 μm high-voltage CMOS technology.
• To enhance magnetic sensitivity and reduce output offset through innovative Hall plate and signal conditioning designs.
• To demonstrate the performance of a monolithic Hall sensor microsystem suitable for various applications.

Main Methods:

• Fabrication of a monolithic Hall sensor chip using 0.8 μm high-voltage CMOS technology.
• Implementation of a highly sensitive horizontal switched Hall plate with a cross-like design.
• Integration of an efficient signal conditioner with a dynamic offset cancellation technique and a spinning current modulator.
• Testing and characterization of the Hall sensor's output voltage, linearity, offset, and power consumption.

Main Results:

• Achieved high magnetic sensitivity and low residual offset (0.48 mT).
• Demonstrated excellent linearity (>99%) over a wide magnetic flux density range (±5 mT to ±175 mT).
• Maximum Hall output voltage reached ±2.1 V at a 5 V supply voltage with static power consumption of 20 mW.

Conclusions:

• The presented monolithic Hall sensor microsystem achieves high performance metrics, including sensitivity, linearity, and low offset.
• The integration of advanced techniques like dynamic offset cancellation and spinning current modulation enhances reliability and accuracy.
• The developed Hall sensor is suitable for applications requiring precise and stable magnetic field detection.