Methods, apparatuses, and systems for providing a variable output using an array of cells are discussed. In the fine tuning bank of an apparatus, control is implemented by selecting a boundary cell from the array of cells and having every cell before the boundary cell in a circuit path be grounded and having the boundary cell and every cell after the boundary cell in the circuit path be connected to a voltage source. The circuit path may be the one formed by using thermometer coding in the fine tuning bank.