Patent ID: 8238111

Claim:
A printed circuit board (PCB) comprising: a signal layer comprising an analog audio input/output (I/O) port arranged on one side of the signal layer, and an audio chip arranged adjacent to the analog audio I/O port, wherein the audio chip comprises a main body, a first group of signal pins electrically connected to the analog audio I/O port and a second group of signal pins electrically connected to a control chip; a power layer divided into two unconnected parts, namely, a first audio part and a first digital part, by a first dividing groove; and a ground layer divided into two unconnected parts, namely, a second audio part and a second digital part, by a second dividing groove; wherein the two audio parts act as a whole reference plane for traces between the analog audio I/O port and the first group of signal pins of the audio chip, the two digital parts act as reference planes for traces between the control chip and the second group of signal pins of the audio chip.