Abstract: The first proposed circuit includes: a voltage supply; a first current source, including: a first transistor having a first terminal coupled to the voltage supply, a second terminal providing the PTAT current and coupled to an output terminal of the circuit for providing a bandgap reference voltage, and a control terminal; a second current source, including: a first resistor having a first terminal coupled to the voltage supply; and a second transistor having a first terminal coupled to a second terminal of the first resistor, a second terminal providing the PTVBE current and coupled to the output terminal, and a control terminal; and a second resistor having a first terminal coupled to the output terminal, and a second terminal coupled to a common ground. Two current mirror circuits are employed in this circuit.

Abstract: A method for driving a light emitting diode coupled to an output of a current mirror is provided. The method includes providing a control terminal voltage of the current mirror as a reference voltage, increasing a voltage of an input of the current mirror and providing an input of the light emitting diode as a voltage feedback point for keeping a constant voltage difference between the input and the output of the current mirror, and driving the light emitting diode by a voltage at the output of the current mirror.

Abstract: A method for driving a light emitting diode coupled to an output of a current mirror is provided. The method includes providing a control terminal voltage of the current mirror as a reference voltage, increasing a voltage of an input of the current mirror and providing an input of the light emitting diode as a voltage feedback point for keeping a constant voltage difference between the input and the output of the current mirror, and driving the light emitting diode by a voltage at the output of the current mirror.

Abstract: The first proposed circuit includes: a voltage supply; a first current source, including: a first transistor having a first terminal coupled to the voltage supply, a second terminal providing the PTAT current and coupled to an output terminal of the circuit for providing a bandgap reference voltage, and a control terminal; a second current source, including: a first resistor having a first terminal coupled to the voltage supply; and a second transistor having a first terminal coupled to a second terminal of the first resistor, a second terminal providing the PTVBE current and coupled to the output terminal, and a control terminal; and a second resistor having a first terminal coupled to the output terminal, and a second terminal coupled to a common ground. Two current mirror circuits are employed in this circuit.