Hall Effect Voltage

Formula

Description

The Hall effect produces a voltage perpendicular to both current flow and an applied magnetic field. When current-carrying charge carriers are deflected by the Lorentz force, they accumulate on one side of the conductor, creating a measurable voltage. The Hall coefficient Rh depends on the carrier concentration and type (positive for p-type, negative for n-type semiconductors). Hall effect sensors are ubiquitous in current sensing, position detection, speed measurement, and brushless motor commutation.

Variables

• Vh — Hall voltage (V)
• Rh — Hall coefficient (m³/C)
• I — Bias current through the Hall element (A)
• B — Magnetic flux density (T)
• t — Thickness of the Hall element (m)

Practical Notes

Semiconductor Hall elements (InSb, GaAs) have much larger Hall coefficients than metals, producing larger voltages. Integrated Hall sensors like the ACS712 combine a Hall element with signal conditioning for easy current measurement. Linear Hall sensors output voltage proportional to field, while switch/latch types output digital signals. Sensitivity is typically 1-5 mV/mT for raw Hall elements.