Patent ID: 9141500
Filing Date: 2015-09-22
Classification: G06F,H04L

Abstract:
1. A test board for a Power over Ethernet device, comprising: a DC power input terminal for connection to a DC power supply; a network connector; a detection circuit, controlled by a first control signal and a second control signal and having: a first power terminal, receiving a first DC voltage originating from the DC power supply; a first output terminal coupled to the network connector; a first resistor, coupling the first power terminal to the first output terminal when the first control signal is enabled to present a first voltage level at the first output terminal; and a second resistor having a resistance different from that of the first resistor, wherein when the second control signal is enabled, the second resistor couples the first power terminal to the first output terminal and thereby the first output terminal is at a second voltage level, wherein a voltage difference between the first and second voltage levels shows whether a powered device is connected to the network connector; and a classification circuit controlled by a third control signal and having: a second power terminal receiving the first DC voltage; a second output terminal coupled to the network connector; and a third resistor, wherein when the third control signal is enabled, the third resistor couples the second power terminal to the second output terminal and thereby a first current flows through the third resistor; wherein the first current shows a classified result of the powered device which is connected to the network connector.