Temperature compensation of Hall elements
A hall element is a sensor, sensitive to the magnetic field. It is used as the non-contact current probe for oscilloscope, a non-contact potentiometer, etc.. For a GaAs type element, however, it has a temperature coefficient of around -600×10-6/K（max.）, which needs to be compensated.
A typical application circuit is shown. The Hall element is fed with a constant current and a differential voltage will be derived proportional to the applied magnetic field. This voltage is amplified and just compensated by the Rc, which is the specifiable linear positive temperature coefficient (PTC) resistor LT73 or LA73. We recommend LT73V for automotive applications.
Temperature compensation of Hall Element