DCM反向电流优化全集成KY变换器设计

Fully Integrated KY Converter with Optimized Reverse Current for DCM Operation

针对一种新型升压变换器——KY变换器提出了NMOS管漏端电压采样的控制方法,通过合理设计开关管工作的时序及负反馈控制电路,达到更为准确的过零关断效果.采用标准0.18μm CMOS工艺,完成了一款全集成KY变换器的设计,开关频率为100 MHz.仿真结果表明,变换器输入电压为1.8V,输出电压为2.5V,负载电流为150mA时,变换器的峰值效率为81.3%,与常规通过检测电感电流过零点,继而关断开关管的KY变换器相比,效率提高了4.5%.

By analyzing the topology of KY converter and the reverse current problem, a NMOS drain-voltage sampling control loop is proposed. Reasonable sequential circuit and feedback controller are designed and more accurate zero-crossing turn-off is achieved. A fully integrated 100 MHz KY converter is designed based on a standard 0. 18 μm CMOS process. The simulation results show that the reverse current is reduced. The peak efficiency is 81.3% when input voltage is 1.8 V, output voltage is 2. 5 V and load current is 150 mA. Improvement of 4. 5% is achieved compared with other circuit which turns off the switches based on the normal zero-crossing signal of inductor current.