平面变压器5V／12A高功率密度开关电源设计

摘要

Planar transformer can reduce the size of switching power supply, and synchronous rectifier can improve the efficiency of low voltage high-current switching power supply. In this paper, with the symmetrical half-bridge circuit as the main circuit and TL494 as the control chip, a 48 V/5 V (12,4) high power density switch power supply is developed by using of planar transformers and synchronous rectification. The power supply has the function of over-current, overload protection; at the same time, the paper shows the design of main circuit and control circuit and calculation process of the planar transformers parameter. Experimental results show that the peak of power supply output voltage ripple at full load is only 10 mV, efficiency is up to 90%. the volume is only 50 mm× 45 mm×30mm.%平面变压器可减小开关电源的体积，同步整流可提高低压大电流开关电源的效率。以对称半桥式电路为主电路、TL494为控制芯片、采用平面变压器和同步整流技术研制了一台48V／5V（12A）高功率密度开关电源，该电源具有过流、过载保护功能；同时，给出了主电路和控制电路的设计方案、平面变压器参数的计算过程。实验结果表明，该电源满载时输出电压纹波峰峰值仅为10mV，效率可达90％，体积仅有50mm×45mm×30mm。