Circuitry, operating in a high voltage domain, including a high and low voltage inputs, and including a plurality of devices designed to operate optimally powered in a native voltage domain that is lower voltage than said high voltage domain and some devices arranged in two sets. The circuitry including a further input for receiving the high native voltage level. Each set having at least one device, a first set being arranged to receive an intermediate low reference voltage level as a low voltage level signal and the high voltage level as a high voltage level signal and the second set being arranged to receive the high native voltage level as a high voltage level signal and the low voltage level as a low voltage level signal. The intermediate low reference voltage level includes a voltage level generated by subtracting the high native voltage level from the high voltage level.