A Hall-effect device for detecting a magnetic flux intensity has a pair of input terminals connected respectively to a constant-voltage regulated power supply and an FET. The FET has a gate connected to the output terminal of an operational amplifier. One of the input terminals of the operational amplifier...http://www.google.com/patents/US5550469?utm_source=gb-gplus-sharePatent US5550469 - Hall-effect device driver with temperature-dependent sensitivity compensation
