How to choose a PoE splitter? Super complete knowledge of PoE splitter

PoE splitter is usually called PoE splitter by many people. Are there still many people who don‘t know the function of PoE splitter? Don‘t know how to choose the right one? It doesn‘t matter, the editor of Fengrunda will explain it to you in detail below.

What is a PoE splitter?

It is a PD power receiving device, which is used to separate PoE (data + power) signal points and send them to non-PoE network terminals such as network cameras and wireless APs to form a PoE power receiving device (PoE split line + network camera = PoE network camera). ).

Why use a PoE splitter?

There are two main reasons: First, the project has purchased a network camera without PoE, but wants to use PoE for networking. Another is the cost consideration, the price of the IP camera plus the PoE splitter cable is much lower than the price of the PoE IP camera.

Why do some PoE splitters burn IP cameras?

The main reason is that the transformers used by some manufacturers‘ PoE splitters are non-isolation transformers. When subjected to a voltage shock, the high voltage will destroy the transformer along the circuit and destroy the network camera body. The isolation transformer used by Fengrunda‘s PoE splitter has circuit isolation protection, which can effectively protect the electrical equipment.

Why some PoE splitters can only be used with specific PSE power supply equipment?

The main function of the PoE splitter is to perform a protocol handshake with the PSE power supply equipment, negotiate the PoE voltage and power supply process, and the selection of this device determines the compatibility and matching degree of the PoE camera. PoE splitters are divided into standard PD powered devices and diode PD powered devices.

Standard PD chip realizes PoE power supply:

Before the PoE link is established, the standard PSE power supply device will send a handshake signal to the PD, and the PD will give a feedback. The two parties agree on the power supply voltage and the power consumption of the PD. The PSE then transmits power to the PD terminal to complete the power supply work. Since the default driving voltage of the PD chip is 48V, even if the PSE is a non-standard 48V power supply device, it can drive the PD to work, so the use of a standard PD chip to achieve PoE has higher compatibility.

PoE is implemented by means of diode jumping:

Since there is no PD chip, when the standard PSE power supply device sends a handshake signal to the PD, the PD cannot give feedback, and the two parties cannot reach a power supply agreement. The diode jump is used to realize PoE, but the 48V power is forcibly injected through the spare wire pair of the network cable. , to promote the subsequent power supply work. This method uses a special method for power input without certain standards and specifications, so it has great limitations and is incompatible with power supply equipment.

PoE splitter price difference?

There are two people who decide the price of the separation line: labor cost and material cost. The labor cost is similar, the material cost is reflected in the materials used, and the price of good devices will naturally be higher. The two most important components of the PoE splitter and the two most expensive components are the transformer and the PD chip. The choice of these two components directly determines the quality of the device, which also determines the price of the device. The following is the device selection and characteristics of the PoE splitter from each manufacturer:

Non-isolation transformer + diode: the cheapest, no protection for the camera, poor compatibility

Isolation transformer + diode: low price, protection for cameras, poor compatibility

Non-isolation transformer + standard PD chip: moderate price, no protection for cameras, good compatibility, most likely to mislead customers

Isolation transformer + standard PD chip: The price is high, the camera is protected, the compatibility is good, and the optimal PoE module solution. The scheme used in the samples provided by Fengrunda is the last scheme.

How to choose a PoE splitter?

1. Look at the appearance: the performance of the device that looks beautiful is not necessarily good, but the performance of the device that looks very bad must not be much better. The mature products of good manufacturers must have beautiful appearance and standard production.

2. Look at the performance: the main technical parameters of the high-quality PoE splitter support the PoE standard and also support IEEE802.3af,

IEEE802.3at power supply standard; the power supply mode supports both 12/36-pin power supply and 45/78-pin power supply, and adopts an isolated design. These conditions must be met at the same time to ensure the stable operation of the product and not cause damage to external equipment.

3. Look inside: Take it apart to see if the components inside are reasonable, and whether the circuit design is smooth and clean. Excellent product internal design will give people a pleasing feeling, and there should be no less protective devices, and poor products are chaotic inside, and the materials are extremely simple. Sometimes, although the functions are not much different, the design materials are quite different.