Magnetic gain correction of hall effect sensors

A circuit comprising:

• a reference current generator having an input, a first terminal, and a second terminal, the reference current generator including a resistor circuit having a first terminal coupled to the first terminal of the reference current generator and a second terminal coupled to the second terminal of the reference current generator;
• a current mirror having a first terminal, a second terminal coupled to the first terminal of the reference current generator, a third terminal, and a fourth terminal coupled to the second terminal of the reference current generator;
• a Hall effect sensor having a first terminal coupled to the first terminal of the current mirror and a second terminal coupled to the third terminal of the current mirror;
• a temperature sensor having an output;
• and
• a temperature compensation circuit having a first input coupled to the output of the temperature sensor, a second input coupled to the input of the reference current generator, and an output coupled to the second terminal of the current mirror.

A temperature compensation circuit having a first input, a second input, and an output, the temperature compensation circuit comprising:

• a first current source having an input and an output;
• a first transistor having a first terminal coupled to the output of the first current source, a second terminal, and a control terminal coupled to the first terminal;
• a second transistor having a first terminal coupled to the second terminal of the first transistor, a second terminal, and a control terminal coupled to the first input of the temperature compensation circuit;
• a third transistor having a first terminal coupled to the input of the first current source, a second terminal, and a control terminal coupled to the control terminal of the first transistor;
• and
• a fourth transistor having a first terminal coupled to the second terminal of the third transistor, a second terminal coupled to the output of the temperature compensation circuit, and a control terminal coupled to the second input of the temperature compensation circuit.