Technology

SENTRON Hall sensors respond to a magnetic field parallel with the chip surface and not, as conventional Hall sensors, to a field perpendicular to the device surface. They are also more sensitive than conventional Hall sensors. From the application point of view, SENTRON Sensors are similar to magneto-resistive sensors (AMR and GMR). However, they do not have the drawbacks of magnetoresistors, such as non-linearity, hysteresis, flipping, and limited safe field range.

Moreover, SENTRON Hall Sensors are fully integrated sensor micro-systems, including Hall elements, biasing circuit, amplifier, and programming of gain, offset, and temperature coefficient. Available are single-axis and 2-axis Hall sensors.

The extraordinary features of SENTRON Hall Sensors are due to the application of SENTRON unique IMC-Hall® Technology. IMC stands for Integrated Magnetic Concentrator. An IMC is a ferromagnetic structure integrated at the surface of a Hall sensor die, which guides a magnetic flux to the Hall elements. An IMC provides a magnetic gain and the response to a magnetic field parallel with the chip surface. IMC Hall Technology was developed in cooperation with the lab of Prof. Dr. R.S. Popovic of Swiss Federal Institute of Technology Lausanne (EPFL).

Although unique and innovative, the IMC-Hall Technology is not an exotic technology. An IMC Hall magnetic sensor consists of the following three building blocks:

a) A silicon Hall ASIC die, fully fabricated in conventional 0.8 mm CMOS process;

b) An IMC, consisting of a 20 um thick soft ferromagnetic layer. The IMCs are integrated on the CMOS Hall wafers in a low-temperature and non-invasive post-process. The material used for IMC is very robust and chemically stable: it is similar to stainless steel. All other applied materials are commonly used in the semiconductor industry;

c) A plastic package. The packaging technology is identical to that used for conventional Hall ASICs.

Therefore, the magnetic sensors based on the IMC-Hall Technology (types CSA and 2SA) are as reliable as conventional CMOS Hall sensors.