ULTRA-LOW POWER CONSUMPTION POE POWER SUPPLY UNIT

An ultra-low power consumption Power over Ethernet (PoE) power supply unit, comprising: a main power supply module, a PoE system module, a powered device (PD) detection circuit module, a first switch (K1), a second switch (K2), an output terminal module and an auxiliary power module. The PD detection circuit module comprises a comparator, a first resistor (R1), and a second resistor (R2). An input terminal of the comparator is connected to a first contact of the first switch, and another input terminal is connected to a reference voltage (Ref) by means of the second resistor, an output terminal of the comparator being connected to the main power supply module. A terminal of the first resistor is connected to a low power supply voltage (Vcc), and another terminal is connected to a first contact of the second switch; a second contact of the first switch is connected to the PoE system module, while a third contact of the first switch is connected to the output module, a second contact of the second switch being