数字化X荧光仪电源的最优化设计  

Optimized Design of Digital X-ray Fluorimeter Power Supply

作　　者：曾国强[1] 葛良全[1] 倪师军[1] 熊盛青[2] 

机构地区：[1]成都理工大学,四川610051 [2]中国国土资源航空物探遥感中心,北京10083

出　　处：《核电子学与探测技术》2012年第6期719-723,共5页Nuclear Electronics & Detection Technology

基　　金：国家自然科学青年基金"航空伽马数字能谱仪的实时核信号处理算法研究"(40904054)

摘　　要：针对数字化X荧光仪的低功耗、低噪声等要求进行了电源最优化设计。文中对数字梯形滤波器进行了Simulink仿真,根据仿真结果得到最佳的M,N系数,由此确定微分电路的时间常数,最后确定高压电源的最佳开关频率点,降低了高压偏置电源噪声对系统的干扰。还分析了数字梯形滤波器及高速ADC采样的特点,设计了最优化的低压供电系统,进一步降低低压电源对系统的干扰。为了提高Si-Pin探测器制冷电源的供电效率,采用了高效率DC-DC、LDO芯片与检流芯片完成高效率恒流源的设计。实测高压电源的交流纹波小于3.5 mV,带载功耗小于70 mW,恒流源的带载转换效率83%,纹波电压小于12 mV,相同条件下采用文中电源系统可提高谱线的能量分辨率。Optimized designing of power supply to meet the digital X-ray fluorimeter demand of low noises and power dissipation.Simulated the digital trapezoid filter by SIMULINK tools,got the beset M,N coefficient from the simulation result,therefore decided the time constant of differentiating circuit,and finally confirmed the optimized switching frequency about high voltage power supply.By the methods reduced the interference come from high voltage power supply.Analyzed the characteristic of digital trapezoid filter and high speed adc sampling system,so designed the optimized low voltage power supply,reduce the interference from low voltage power supply.Designed the high efficiency constant current source by DC-DC、LDO chips and current sensing chips,then improved the power efficiency of Si-pin detector cooler power.Measured results show： the ac voltage ripples of high voltage power less than 3.5 mV,power dissipation less than 70 mW,conversion efficiency of constant current source is 83%,ripple voltage less than 12 mV,in the same conditions this optimized power supply design could improve the energy resolution of spectroscopy.

关 键 词：数字化X荧光仪 数字梯形滤波器 高压电源 恒流源 

分 类 号：TL825[核科学技术—核技术及应用]