A method and system are disclosed for calibrating a mid-voltage node in an integrated circuit including an input-output circuit having charge-recycling stacked voltage domains including at least first and second voltage domains. In one embodiment, the method comprises transmitting data through the input-output circuit, including transmitting a first portion of the data across the first voltage domain, and transmitting a second portion of the data across the second voltage domain. The method further comprises measuring a specified characteristic of the data transmitted through the input-output circuit; and based on the measured specified characteristic, adjusting a voltage of said mid-voltage node to a defined value. The voltage of the mid-voltage node may be adjusted to accomplish a number of objectives, for example, to achieve a desired trade-off between power and performance, or so that the two voltage domains have the same performance.