Voltage reference circuit and method for providing reference voltage

Voltage reference circuits are provided. A voltage reference circuit includes a first transistor, a flipped-gate transistor, a first current mirror unit, a second current mirror unit, and an output note. The first transistor is formed by a plurality of second transistors. A gate and a drain of the flipped-gate transistor are coupled to a gate and a drain of each second transistor. The first current mirror unit is configured to provide a first current to the flipped-gate transistor and a mirroring current in response to a bias current. The second current mirror unit is configured to drain a second current from the first transistor in response to the mirroring current. The output node is coupled to a source of each second transistor and the second current mirror unit, and configured to output a reference voltage. Size of the flipped-gate transistor is less than that of the first transistor.