Low Emi And Low Static Power Ac / Dc Converter Design

As the AC/DC switching power get wide application, low power, such as 3W to 5W has huge potential in market of AC/DC switching power. So we plan to design this power.Nowadays AC/DC switching power not only should get good voltage regulation, good load regulation, good temperature of output voltage, protection of short, etc, but also should get lower EMI characters and lower no load power consumption.The article takes spread spectrum technology by the method of frequency jittering to lower EMI in switching power. There are many traditional method to lower EMI, such as to add EMI filter, to add snubber circuits, to add Y capacitance, etc.Because no load power consumption is in proportion to frequency of switching power. So when frequency of switching power is lower, no load power consumption is lower too. When IC is working in pulse skipping mode, frequency of switching power will lower, then no load power consumption is lower too. There are many standard of no load power consumption. The standard of The energy star set the no load power consumption should lower than 0. 3W.The article designs the PWM IC and the application of the PWM IC. At last we get the good report in final the application of the PWM IC test.