Sensor-less circuit and method for detecting a rotor position

A voltage detection circuit, comprising:

• a current generation circuit having a first terminal, a second terminal, and a third terminal;
• a current trimming circuit having a biasing terminal, a first control terminal, and a first current conduction terminal, the biasing terminal coupled to the third terminal of the current generation circuit;
• a voltage divider circuit having a first terminal, a second terminal, and a node, the first terminal of the voltage divider circuit coupled to the first current conduction terminal;
• a first current mirror having a first terminal and a second terminal, the first terminal of the first current mirror coupled to the second terminal of the voltage divider circuit;
• and
• a first comparator having an inverting input terminal, a noninverting input terminal, and an output terminal, the noninverting input terminal of the first comparator coupled to the second terminal of the voltage divider circuit.

A method for sensorlessly detecting a rotor position of a motor, comprising:

• generating a first voltage in response to a first back electromotive force;
• generating a second voltage in response to a common voltage from the motor;
• generating a third voltage in response to the common voltage from the motor;
• comparing the first voltage with the second voltage to generate a first comparison signal;
• comparing the first voltage with the third voltage to generate a second comparison signal;
• and
• generating a position detection signal in response to the first comparison signal and the second comparison signal.