How do we assess the power supply performance of a PoE ONU or switch? Most manufacturers handle this aspect vaguely, emphasizing the functional characteristics of the ONU and switch. However, we should pay more attention to the power supply. A well-designed power supply generally indicates a decent device performance.
| project | For example | Precise explanation |
| Input Voltage Range | 100-240V | A good power supply must be wide-range so that even in remote areas or industrial sites where the mains voltage is unstable (such as suddenly dropping to 110V or soaring to 240V), the equipment can still work normally without restarting or burning out. |
| Efficiency (%) | ≥90% | Higher efficiency means less electrical energy is wasted when the power source converts AC to DC. Wasted electrical energy is converted into "heat," so high efficiency = less heat generation = longer lifespan. |
| Output Voltage Range | 52V | 52V is the typical supply voltage for standard PoE+ (802.3at) devices. A good power supply must have a precise output voltage with minimal fluctuation. |
| Load Current | 0.92A | A poor-quality power supply may only achieve its rated 0.92A output at room temperature (around 25°C), and will dredge at higher temperatures (for example, it may only output 0.5A at 50°C, making it unable to power the equipment). A good power supply must be able to output 0.92A (approximately 48W) at its maximum rated operating temperature (e.g., 50°C or 60°C). |
| Ripple （mV） | ≤100 mV | Ripple refers to the alternating current "noise" mixed in with direct current. It's like waves in water; the smaller the better. For a 52V voltage, a ripple of 100mV represents only 0.19%, which is a very clean and smooth power supply. The smaller the ripple, the more stable the operation of the underlying precision chips, and the less likely they are to crash or lose data. |
| Short Circuit Protection |
| When a short circuit occurs, the power supply will automatically cut off the output to protect itself; when the short circuit is resolved, the power supply will automatically resume power supply without requiring manual unplugging and restarting. |
| Over Current Protection |
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| Leakage Current | ≤0.5mA@220VAC | Leakage current is an important indicator of electrical safety. The lower the leakage current, the safer it is for the human body. For example, ≤0.5mA is within the excellent range that meets safety standards, and you will not feel a "tingling" sensation when you touch the casing. |
