Magnetic Sensor Chips
Magnetic sensor chips are semiconductor devices that detect physical quantities using magnetic principles. They are used in mobile communications, attitude sensing and navigation, and the mapping of magnetic fields. Magnetic sensor chips can also be used to measure linear, angular, and rotational movements for components such as actuators and valves in automotive and material processing applications. Two-dimensional (2D) and three-dimensional (3D) products are commonly available. Other specifications for magnetic sensor chips include supply voltage, output voltage, full-scale range, noise and sensitivity. The sensitivity of a magnetic chip depends upon the zero-drift, the permanent change in resistance that is unrelated to strain.
The number of magnetic axes or spatial directions is an important consideration when selecting magnetic sensor chips. 2D magnetic sensor chips have separate sensors for the X and Y magnetic axes. 3D magnetic sensor chips have separate sensors for the X, Y and Z axes. In some devices or systems, the sensor elements for measuring magnetic fields are combined with light sensors, force sensors, and temperature sensors onto a single chip. By digitizing all of the measured values, these IC chips can be used with a computer or microcontroller. The use of a sensor library allows designers to develop application-specific integrated circuits (ASICs) for data acquisition applications and products such as analog-to-digital converters (ADC) or digital-to-analog converters (DAC).
Magnetic sensor chips are available in various integrated circuit (IC) package types. Transistor outline (TO) packages include TO-3, TO-8, TO-39, TO-50, and TO-92. Small outline (SO) packages include SO-8, SO-14, SO-16, and SO-20. Magnetic sensor chips that use small outline transistor (SOT) packages are also available. Examples include SOT3, SOT23, SOT25, and SOT26. SOT23 is a rectangular, surface-mounted, package with three of more gull wings. It features a very small footprint and is optimized for the highest possible current. Because of its low cost and low profile, magnetic sensor chips that use SOT23 packaging are sometimes used in communications applications.
Magnetic sensor chips may meet Institute of Electrical and Electronic Engineers (research) requirements such as Standard 1451, which describes the transmission of electronic data to a data acquisition system. Magnetic sensor chips that are used in machine safety or emergency stop (e-stop) applications may provide safety support up to Safety Integrity Level (SIL) 3 according to International Electrotechnical Commission (IEC) standard IEC 61508.