Low power comparator

A method of comparing voltages, the method comprising

• receiving an input voltage at an input port;
• dividing the input voltage with a resistive divider to provide a first voltage at a first node and a second voltage at a second node;
• providing a first transistor having a control terminal coupled to the first node, a first terminal coupled to the input port, and a second terminal coupled to a common node;
• providing a second transistor having a control terminal coupled to the second node, a first terminal coupled to the input port, and a second terminal coupled to the common node;
• providing a differential amplifier having a first input coupled to the first terminal of the first transistor, a second input coupled to the first terminal of the second transistor;
• and
• generating a difference voltage using the differential amplifier,
• wherein the first transistor is coupled to the input port via a third transistor, and wherein the second transistor is coupled to the input port via a fourth transistor,
• wherein the third transistor has a control terminal coupled to the first input of the differential amplifier, and wherein the fourth transistor has a control terminal coupled to the second input of the differential amplifier, and
• wherein the first transistor is an anti-doped gate transistor in which the gate of the first transistor is doped with a doping type opposite to that of the first transistor type, and wherein the second transistor is a normal gate transistor in which the gate of the second transistor is doped with a same doping type as the second transistor type.