Several important technical indexes of switching power supply.

Switching power supply is favored by people for its low power consumption, high efficiency and small volume, and is widely used in computer equipment, electronic instruments, communication equipment and household appliances. The main technical indicators of switching power supply are described below.

1. Input voltage range: when the input voltage of the switching power supply changes, the input voltage variation range of the output characteristic is kept constant. The wider the range, the more power the power ADAPTS to the outside world, and the wider the switching power supply. It is related to the error amplifier in the switching power supply, the gain of the sampling feedback regulating circuit and the control range of the duty cycle. The current input voltage range of the switching power supply has reached 90V-270V, which can eliminate the 110V/220V switch on many electrical appliances.

2. Voltage regulation: voltage regulation is also known as voltage stability, is in a constant output current (i.e., the load does not change), and the input ac voltage changes, the relative change of the output voltage. This technical index is used to verify whether the stability of the output voltage meets the requirements specification in the most severe power supply voltage environment.

3. The current regulation: the current regulation is also called the load regulation, is in the input ac voltage for rating (220 vac), and the output current from the minimum value of 0 to the maximum, the relative variation of the output voltage. This indicator is used to verify that the output voltage stability of the switching power adapter is in accordance with the requirements in the worst load environment.

4. Output resistance: the ratio of the change in output voltage to the change in the output current. The smaller the ratio, the smaller the power output voltage varies with the load size, and the stable performance is good.

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

6. The output voltage ripple: due to the switching power supply voltage process is a process of constant sampling feedback adjustment, therefore in the dc voltage output from a stack of ripple voltage, that is, the output ripple voltage. The smaller the value, the better the output feature. There are two ways to express ripple: one is the effective value of the output ripple voltage; The second is the peak value of the output ripple voltage. The specification of general switching power supply is less than 1% of the output dc voltage, and its bandwidth is 20hz-20mhz or other higher frequencies, such as 100MHz. Switching power supply in harsh environments, the output after noise ripple dc voltage and the output of the instantaneous voltage, output high and low voltage lines should not exceed (Min and Max values), or more or less will likely lead to supply voltage logic circuit, such as TTL circuit working voltage and misoperation, further crash phenomenon.