Semiconductor device, magnetic sensor, and physical quantity sensor
A semiconductor device includes: a detection Hall element for detecting a magnetic field; a temperature monitor Hall element; and a calculation circuit. The detection Hall element has a characteristic, which is almost a same as the temperature monitor Hall element. The detection Hall element is disposed near the temperature monitor Hall element. The detection Hall element outputs a Hall voltage. The temperature monitor Hall element includes a pair of driving signal supply terminals for outputting a temperature monitor voltage. The calculation circuit calculates to cancel a temperature characteristic of the Hall voltage based on the Hall voltage and the temperature monitor voltage.
1. A magnetic sensor comprising:
a Hall element for detecting a magnetic field generated from a detection object, wherein the Hall element outputs a Hall voltage, and includes a pair of driving signal supply terminals for outputting a temperature monitor voltage;
a switching element for switching between an output of the Hall voltage and an output of the temperature monitor voltage; and
a calculation circuit, wherein
the calculation circuit calculates to cancel a temperature characteristic of the Hall voltage based on the Hall voltage and the temperature monitor voltage
the calculation circuit is an adder circuit for adding the temperature monitor voltage to the Hall voltage; and
the switching circuit is coupled with a pair of input terminals of the adder circuit so that the Hall voltage and the temperature monitor voltage are alternatively input into the adder circuit.
2. The sensor according to claim 1 , wherein the Hall element is operated with a constant current.
3. The sensor according to claim 1 , wherein the Hall element is operated with a constant voltage.
4. The semiconductor device according to claim 1 , further comprising:
a substrate, in which the Hall element is disposed, and
the Hall element is a vertical Hall element for detecting a magnetic field component in parallel to a substrate surface.
5. The sensor according to claim 1 , wherein
the calculation circuit further includes a sampling hold circuit for holding the temperature monitor voltage as when the switching element switches to the output of the temperature monitor voltage, and wherein
adder circuit adds the Hall voltage and the temperature monitor voltage, the Hall voltage being input from the switching element when the switching element switches to the output of the Hall voltage, and the temperature monitor voltage being held in the sampling hold circuit.
6. The sensor according to claim 5 , wherein
the Hall voltage is exponentially reduced as temperature rises, and wherein
the temperature monitor voltage is exponentially increased as temperature rises.