The present invention relates to a digital filter suitable for receiving a digital input signal ) comprising a voltage peak also known as glitch. On the other hand, no film made from a material that varies the emissivity, such as a DPS film, is formed on the reverse face of the substrate 10. Each node includes a literal identifier that refers to an instance of one of a plurality of types of data structures and a node ID that uniquely distinguishes the node from the remaining nodes in the tree. The cluster of connection wires is provided with a plurality of connection seats for connecting with the power cord set, and the other end of the power cord set is provided with a power connector corresponding to future expanded equipments and elements for various different specifications.