HALL SENSOR DRIVING CIRCUIT AND POINTING APPARATUS THEREOF

摘要

A hall sensor driver circuit and a pointing device using the same are provided to exclude a power circuit generating static voltage for driving a hall sensor and to secure a self-amplification function by non-linearly increasing hall voltage by increasing magnetic flux density applied on the hall sensor. A hall sensor driver circuit(300) includes: a driving power source with predetermined voltage(Vcc); a hall sensor(U7) for detecting the change of peripheral magnetic flux density and changing output voltage(V2) of two output terminals correspondently to the detected magnetic flux density; an amplifier(U8) for receiving one of reference voltage(Vref) lower than the voltage of the driving power source and the output voltage of the hall sensor and outputting a control signal generated by amplifying the difference between the reference voltage and the output voltage of the hall sensor; and a switching element keeping the output voltage input to the amplifier correspondently to the reference voltage by controlling the flow of current input from the driving power source to the hall sensor according to the control signal.