A voltage driver includes a voltage divider, a first transistor and a second transistor. The voltage divider is connected with a first voltage source and a second voltage source, and generates a first bias voltage. A drain terminal of the first transistor is connected with a third voltage source. A gate terminal of the first transistor is connected with the voltage divider to receive the first bias voltage. A drain terminal of the second transistor is connected with a source terminal of the first transistor. A gate terminal of the second transistor receives a second bias voltage. A source terminal of the second transistor is connected with a fourth voltage source. The first transistor and the second transistor are of the same conductivity type and match each other. The source terminal of the first transistor generates an output voltage.