Main advantages of AC/DC switching power adapter chips
The AC/DC switching power adapter chip (or module) can be made into a basic switching power adapter by combining some resistive capacitive components and a switching transformer.
The main working principle of a regular half bridge switching power adapter is that the switching tubes of the upper and lower bridges (VMOS when the frequency is high) alternate conduction. First, current flows in through the upper bridge switching tube, and the storage function of the inductor coil is used to gather electrical energy in the coil. Finally, the upper bridge switching tube is closed and the lower bridge switching tube is opened, and the inductor coil and capacitor continue to supply power to the outside. Then close the lower bridge switch tube and open the upper bridge to allow current to enter, and repeat this process. Because it requires alternating switching of two switching tubes, it is called a switching power adapter.
As a switching power IC in AC-DC power adapters. The main advantages of AC/DC switching power adapters are:
a： Small size and light weight (only 20% to 30% of the size and weight of a linear power adapter)
b： High efficiency (usually 60% to 70%, while linear power adapters only have 30% to 40%)
Strong anti-interference ability, wide output voltage range, and modularity.
The commonly used low-voltage AC switching power adapter rectifies 220VAC electricity directly into an AC voltage of around 300V after passing through an EMI filter. The circuit controls the switching tube to conduct and cut off at high speed, and then converts it into high-frequency AC electricity to be supplied to the transformer for transformation, thereby generating one or more sets of required voltages, which are then rectified into the required AC voltage.
