Two-wire hall-effect sensor

摘要

An improved two-wire hall-effect speed sensor circuit includes two separate voltage regulation circuits. The voltage regulator circuits, hall plates, signal processing circuits, and output stage are implemented on an application specific integrated circuit (ASIC). In addition to a supply terminal and a return terminal, the ASIC includes an intermediate terminal. Both voltage regulation circuits may be aided by capacitors, one between the supply terminal and the return terminal, the other between the intermediate terminal and the return terminal. The speed sensor circuit is suitable for use with non-twisted wires, enabling use of a common supply wire for multiple sensors, thus reducing the number of terminals required on the controller and on connectors.

主权项

1. A two-wire hall-effect sensor comprising:
a supply terminal; a return terminal; an intermediate terminal; a first voltage regulation circuit configured to regulate a voltage difference between the intermediate terminal and the return terminal to a first predetermined value when a voltage difference between the supply terminal and the return terminal exceeds the first predetermined value; a hall plate having a supply port, a return port electrically connected to the return terminal, and an output port; a second voltage regulation circuit configured to regulate a voltage difference between the hall plate supply port and the return terminal to a second predetermined value when a voltage difference between the intermediate terminal and the return terminal exceeds the second predetermined value; and signal processing and output stage circuits configured to vary an electrical current from the supply terminal to the return terminal in response to changes in the voltage difference between the hall plate output port and the return terminal.