An integrated circuit includes first and second voltage domains. The first voltage domain is associated with a positive voltage supply grid and the second voltage domain is associated with a selectably on voltage supply grid. A switch is used to selectably switch on and off the selectably on voltage supply grid to power the second voltage domain. A buffer cell cluster of at least on initial buffer cell and a pair of insulator cells is coupled to the positive voltage supply grid electrically independent of the nodes of a switch and is capable of buffering a feed-through signal having a logic one voltage level defined substantially at the voltage level of the positive voltage supply grid. The buffer cell cluster has two distal ends. buffer cell cluster, at one distal end, is coupled to a first insulator cell of the pair of cells while, at the other distal end, the buffer cell cluster is coupled to a second insulator cell of the pair of the cells.