Patent ID: 8612034

Claim:
A printed circuit board (PCB) comprising: a first 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 first ground layer divided into two unconnected parts, namely, a first audio part and a first digital part, by a first dividing groove; a second signal layer; a power layer divided into two unconnected parts, namely, a second audio part and a second digital part, by a second dividing groove, wherein the second signal layer is located between the first ground layer and the power layer; and a second ground layer divided into two unconnected parts, namely, a third audio part and a third digital part, by a third dividing groove; wherein the first to third 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 first to third digital parts act as reference planes for traces between the control chip and the second group of signal pins of the audio chip.