A circuit includes a first resistive element having a first terminal coupled to an input node to receive a negative voltage, a second resistive element having a first terminal coupled to a first power supply terminal, and a third resistive element having a first terminal coupled to the first power supply terminal. A first current mirror includes a first transistor coupled to a second terminal of the second resistive element and a second transistor coupled to a second terminal of the third resistive element and the first transistor, wherein the output node corresponds to the second terminal of the third resistive element. A second current mirror includes a third transistor coupled to the first transistor and a fourth transistor coupled to the second transistor, third transistor, and a second terminal of the first resistive element. The circuit converts the negative voltage to the positive proportion voltage.