The Main Sensor Types and What Each One Measures
Selecting sensors requires matching physical transduction principles to measurands while accounting for thermal drift, noise floor, and fab availability.
Hall Effect Elements
Semiconductor Plate
Solid state transducers that generate a voltage proportional to the strength of a perpendicular magnetic field provide non-contact current and position sensing. In modern designs, Hall effect elements are integrated directly onto silicon substrates alongside amplification circuitry to deliver stable analog or digital signals.
Flux Interaction
Output voltage generated is proportional to both the bias current and the magnetic flux density passing through the active area. This interaction allows the sensor to detect nearby permanent magnets or magnetic fields from conductors without making mechanical contact with them.
Voltage Offset
Offset voltage is the primary challenge in these devices, occurring even when the magnetic field is zero. This offset is caused by geometric imbalances or piezoresistive stress within the silicon die. Sensor makers reduce this error by using spinning current techniques that dynamically cancel out the offset.
Field Resolution
Temperature variation changes the mobility of carriers in the semiconductor, which can drift the sensitivity of the sensor. High performance devices use on-chip temperature sensors and digital registers to calibrate the gain dynamically across the entire operating range. This correction is done during final assembly and ensures that the magnetic threshold is accurate to within tight tolerances over many years.