混合模式低噪声3kV高压直流电源设计

Design of Low Noise 3kV High Voltage DC Power Supply with Hybrid Mode

高压直流电源是电离室等核辐射探测器的关键部件。针对需要3kV左右高压的电离室,本文研制了0~3kV连续可调的低噪声、高效率、小体积及高稳定性的高压直流电源。该高压直流电源系统采用线性与开关混合模式设计,兼顾了转换效率与低噪声。核心部分升压转换部分采用线性罗耶谐振电路与高频变压器实现,保证足够低的高压电源输出纹波。罗耶谐振电路的供电电源则由边沿时间控制型超低噪声开关稳压器LT1534提供,从而实现了混合模式高压直流电源的设计。高压直流电源输出部分采用二阶RC滤波电路进一步降低了输出电压的纹波。实测输出电压范围为0~3kV,静态功耗为0.4 W,3kV输出时纹波为16.55mV,由此可知该电源可用于低噪声的核辐射探测器供电场合。

The high voltage DC power supply is the key component of the nuclear radiation detector,such as the ionization chamber.For the ionization chamber that needs about 3kV high voltage,a miniature high voltage DC power supply with low noise,high efficiency and high stability was designed in this paper,which can adjust from 0V to 3kV.The high voltage DC power supply system was designed by using hybrid mode with linearity and switch,and it is a compromise between the conversion efficiency and low noise.The core boost conversion circuit adopted linear resonant Royer circuit and high-frequency transformer to ensure sufficiently low output ripple.The power of resonant Royer circuit was provided by ultra low noise switching regulator LT1534,which can control transition time while achieving the design of hybrid mode high voltage DC power supply.The ripple of output voltage is further reduced by using the two-step RCfilter circuit.The measured output voltage range is from 0Vto 3kV,the static power is 0.4 W,and the ripple of 3kV output voltage is 16.55 mV.It shows that the power supply can be used for the nuclear radiation detector of low noise.