The invention relates to a method and apparatus for filtering a liquid. In one aspect, a power transistor device is provided. The number of virtual register address locations reserved is equal to a number of indirect addressing modes associated with the indirect addressing pointer. As a result, excellent optical characteristics can be obtained. Thus, it is possible to enhance the control accuracy in a state in which the lift amount of the engine valve is controlled to be low. In another aspect, electrically conductive material may be added to, or removed from, the high density layout of interdigitated contact pads and larger contact pads to modify, or reconfigure, the electrical pathways of the wafer translator.