3V/10A Low-Voltage High-Current Flyback Tyge Synchronous Rectifier Research And Design Of Switch Power Supply

Resent few years, has witnessed that the development of electronic technology, make the working voltage of the circuit is more and more low, current is bigger and bigger. Low voltage work is helpful to reduce the overall power consumption of the circuit, but it puts forward a new problem to the power supply design.The traditional converter often adopts the ordinary diodes or Scotty diode rectifier, in the case of low voltage, high current output, rectifier diode conduction voltage drop is higher, especially the wastage of the output rectifier. Fast recovery diodes (FRD) or super fast recovery diode (SRD) of the pressure drop can be up to1.0-1.2V, even with low pressure drop of the Scotty barrier diode (SBD), also produces about0.5V voltage, lead to rectifying loss increases, power efficiency decline, has been unable to meet the low voltage high current switching power supply the need of high efficiency and small volume. In this case, it’s necessary to adopt synchronous rectifier (SR) technology, which uses the power MOSFET instead of the traditional or conventional diode for rectifier Scotty diodes. Due to the low power MOSFET turn-on resistance, switch time is short, high input impedance, it greatly reduces the wastage of the switching converter rectifier, improve work efficiency, so it becomes a low-voltage high-current power converter rectifier device of choice.Synchronous rectifier technology combined with the appropriate circuit topology, low-cost high-efficiency converter can be obtained. The flyback converter circuit has advantages of simple topology, input and output electrical isolation, voltage rise/drop range is wide, multiplexed output easily, therefore it is widely used in high voltage, small power occasions, widely used in the5-150w power supply.This paper introduces the design of flyback converter with low voltage and large current based on synchronous rectification, compares the flyback converter with different operation mode, and researches the flyback circuit, synchronous rectification technology. And this paper introduces the principle of Synchronous Rectifier Reverse Converter. This paper analyses the flyback synchronous rectifier circuit theoretically, and establishes analysis of mathematical models, and it designs a85-265V input, single flyback switch power output of3V/10A. Adopt the VIPer53power IC and the power of the MOS by side to implement the rectifier output. Both the theoretical analysis and experimental results test and verify that Synchronous rectification in low voltage high current circuit has the obvious effect to improve the efficiency of the switch power supply, and Flyback synchronous rectifier circuit has great practical value in the low voltage and high current switching power supply of small power.