Magnetic sensors, encoders, and servo motors

Abstract

To provide a magnetic sensor that operates with small power and has a small influence of temperature change.SOLUTION: A magnetic sensor comprises: a Hall element for magnetic sensing that includes a first driving terminal and a second driving terminal, and a first detection terminal and a second detection terminal, and outputs first voltage proportional to magnetic flux density crossing a first driving current flowing from the first driving terminal to the second driving terminal to between the first detection terminal and the second detection terminal; a differential amplifier circuit that includes a first output terminal for outputting voltage obtained by amplifying potential difference between the first detection terminal and the second detection terminal; a Hall element for temperature correction that includes a third driving terminal and a fourth driving terminal, and a third detection terminal and a fourth detection terminal, and in which the third driving terminal is connected to the first output terminal; and an inverting amplifier circuit that outputs voltage obtained by inversely amplifying voltage input into a third input terminal connected to the fourth driving terminal.SELECTED DRAWING: Figure 3