一种高效率低纹波X射线探测器电源的设计

Design of a Low Ripple High Efficiency Power Supply for X Ray Detector

针对X射线探测器在野外现场的供电要求,采用高效率直流/直流升压电源芯片MAX668结合倍压电路与二阶电子滤波器实现高效率低纹波+100 V高压电源的设计。改变传统线性恒流源的设计方式,采用降压开关电源芯片作为电源调整器件,AD623仪表放大器将检流电阻上的电压信号,放大并与电源调整芯片构成负反馈,实现恒流源设计。实测表明,高压电源的静态功耗为14.5 mW,纹波小于15 mV,恒流源输出电流为350 mA时的效率大于81.3%。

Combining with a voltage multiplier circuit and an electronic filter, the high efficiency DC-DC step up controller MAX668 is used to implement a high efficiency low noise positive 100 voltage power supply. Instead of the conventional linear constant current design mode, a step down switch power chip is used as the power regulator, and an instrumentation amplifier chip AD623 is selected to amplify the voltage signal drop on the current sense resistor and construct a negative feedback to the power regulator. Experimental results show that the power dissipation of the high voltage supplier is 14. 5 mW, while the ripple noise is less than 15 inV. When the output current is 350 mA, the efficiency of the constant current source is larger than 81.3%.