A voltage swing decomposition circuit includes first and second clamp circuits and a protection circuit. The first clamp circuit is configured to clamp an output node of the first clamp circuit at a first voltage level when an input node of the voltage swing decomposition circuit has a voltage higher than the first voltage level. The second clamp circuit is configured to clamp an output node of the second clamp circuit at a second voltage level, higher than the first level, when the voltage of the input node is lower than the second voltage level. The protection circuit is coupled to the output nodes of the first and second clamp circuits, and is configured to selectively set an output node of the protection circuit to the first or second voltage level. The first and second clamp circuits are coupled together by the output node of the protection circuit.