An apparatus for performing signal driving in an electronic device may include a decoupling capacitor and at least one switching unit (e.g. one or more switching units). The decoupling capacitor may have a first terminal and a second terminal, and may be positioned in an output stage within the electronic device and coupled between a first predetermined voltage level and another predetermined voltage level, where the apparatus may perform signal driving with aid of the output stage. In addition, the aforementioned at least one switching unit may be coupled between one terminal of the first and the second terminals of the decoupling capacitor and at least one of the first predetermined voltage level and the other predetermined voltage level, and may be arranged for selectively disabling the decoupling capacitor.