An amplifier with an input stage comprising: a first current mirror; a first input differential pair; a first current source; a second current source; a second input differential pair, wherein the first input differential pair and the second input differential pair receive a reference voltage; a second current mirror; and a voltage control transmission circuit. An extra current path in the first current mirror is formed and a current flowing through the extra current path flows through the second current mirror to a ground when the reference voltage is higher than a first predetermined value. Also, an extra current path in the second current mirror is formed and a current flowing through the extra current path in the second current mirror flows to the first current mirror when the reference voltage is lower than a second predetermined value.