An IC chip of magneto-sensitive silicon transistors sensor

A new type differential structure of double-injection long-base magnetic-sensitive Si transistors are the basis of magnetic field sensors. The IC chip of magnetic-sensitive transistors is deigned and the integrated circuit switches from a 1 level to a 0 level when the magnetic-sensitive transistors generator experiences a field level of 400 G. The Schmitt trigger section prevents turn on of the 1 level until the field falls back below 200 G. Such chips may be used as part of Hall effect keyboards to avoid the contact bounce effects of mechanical switches. The IC magnetic-sensitive transistor sensor was fabricated using the poly-silicon epitaxial and VMOS technology.