Abstract:
The invention refers to a method for obtaining an accurately determined high resistance in a resistor produced in a single crystalline substrate in the form of a diffused region limited in length, width and depth direction, which region is covered with an oxide layer and is provided with a first and a second window in the oxide layer for connection of two terminal contacts. According to the invention, a third window is made in the oxide layer on the top of the diffused region by means of a conventional photo-resist and etching technique whereupon the diffused region is etched in the depth direction through the third window for a predetermined time period during which such a quantity of material is removed that the resistance of the quantity of material remaining in the diffused region, measured between the first and second window, will be equal to a predetermined resistance value.
Abstract:
The invention refers to a contactless switch, comprising a Halleffect element that has a pair of input electrodes for applying an operating voltage to generate a current in an internal current path and at least one output electrode located adjacent the current path to derive a Hall-potential when an external magnetic field influences the current laterally, and an amplifier circuit that is controlled by the Hall-potential. According to the invention, the Hall-effect element is provided with at least one control electrode for controlling the magnitude of such current, and the amplifier circuit is provided with at least one output terminal connected to the control electrode of the Hall-effect element for feeding back an amplified Hall-potential in such a phase that the amplifier circuit is provided with positive feedback.