Switching power supply more commonly used for small communication base station, and no one guard room, usually by pulse width modulation (PWM) control IC and MOSFET, as so must be equipped with battery management, power supply product to charge and discharge management, voltage protection, and other functions. As IDC data room commonly used products for high voltage control accuracy requirement is special.
Switching power supply output voltage is not stable, the reason may be caused by multiple factors, so we can only use deduction to determine why.
The first is that the input voltage range of switch power supply more than the terms of the output of the converter to maintain itself too high or too low, this kind of situation will appear voltage instability, you can check whether the circuit is output stability, stable if it would need to adjust the design of the transformer.
The second is where some protection circuit was accidentally triggering causes, such as over voltage, over current, etc., take a closer look at each of the protection circuit of the control node, see which place was accidentally hit by mistake.
And the control circuit of the VDD Wen Bo unstable, is beyond the control of switch power supply IC conditions, this kind of situation you can adjust the power supply voltage or select the appropriate decoupling capacitor to resolve.
Last one way is to switch power supply, internal interference, such as electric current sampling, voltage sampling circuit can cause of switch power supply output voltage instability. You can check the circuit wiring, sensitive circuit to avoid interference sources.