1. Input voltage range: when the input voltage of the switching power supply changes, the input voltage variation range that keeps the output characteristics unchanged. The wider this range, the stronger the ability of the power supply to adapt to changes in the external mains, and the wider the working range of the switching power supply. It is related to the error amplifier inside the switching power supply, the gain of the sampling feedback adjustment circuit and the adjustment range of the duty cycle. At present, the input voltage range of switching power supply has reached 90V-270V, which can save the 110V/220V switch on many electrical appliances.

2. Voltage regulation rate: The voltage regulation rate, also known as voltage stability, is the relative change in the output voltage when the output current does not change (that is, the load does not change) and the input AC working voltage changes. This technical indicator is used to verify whether the stability of the output voltage of the switching power supply meets the required specifications under the most severe power supply voltage environment.

3. Current regulation rate: The current regulation rate, also known as the load regulation rate, is the relative change of the output voltage when the input AC voltage is the rated value (such as 220VAC) and the output current changes from the smallest value 0 to the largest value. . This indicator is used to verify whether the output voltage stability of the switching power adapter meets the required specifications under the most severe load environment.

4. Output internal resistance: The ratio of the change of output voltage to the change of output current. The smaller the ratio, the smaller the change of the output voltage of the power supply with the size of the load, and the better the voltage regulation performance.

5. Conversion efficiency: the ratio of power output power to input power. The higher the ratio, the higher the change efficiency, the smaller the size of the switching power supply, and the higher the reliability. At present, the efficiency of switching power supply can reach more than 90%.

6. Ripple of output voltage: Since the voltage regulation process of switching power supply is a process of continuous sampling and feedback adjustment, there will be a superimposed and fluctuating ripple voltage on the output DC voltage, that is, the output ripple voltage. The smaller the value, the better the output characteristics. There are two ways to express the ripple: one is the rms value of the output ripple voltage; the other is the peak-to-peak value of the output ripple voltage. The specifications of the general switching power supply are required to be less than 1% of the output DC voltage, and its bandwidth is 20Hz-20MHz or other higher frequencies, such as 100MHz. In harsh environments, the output instantaneous voltage of the switching power supply after adding the noise ripple to the output DC voltage should not exceed the output high and low voltage boundaries (Min value and Max value), otherwise it may cause the power supply voltage to exceed or be lower than the logic Circuits (such as TTL circuits)