A pixel of an image sensor includes a polysilicon layer, and an active region which needs to be electrically coupled with the polysilicon layer, wherein the polysilicon layer extends over a portion of the active region, such that the polysilicon layer and the active region are partially overlapped, and the polysilicon layer and the active region are coupled through a buried contact structure. The touch-sensitive panel has a plurality of proximity sensor areas which may be selected by a user wishing to activate associated functions of the appliance. A choke coil of a primary-side series resonant circuit in the class-E switching converter is used as a primary winding N1 in an isolation converter transformer PIT. Alternatively, the triple etching stop layer may comprise a first sub-layer of SiON material, a second sub-layer of TaO material, and a third sub-layer of SiON material. Reducing the amount of light that is absorbed effectively reduces the attenuation of the light absorbing medium. When an input power of the RF input signal increases and makes the working voltage decreases so as to shift the operation bias point, the bias circuit adjusts the working voltage upward so as to recover or enhance the operation bias point according to the compensation voltage received.