【作者】 赵玲；

【导师】 田小建；

【作者基本信息】 吉林大学 ， 电磁场与微波技术， 2012， 硕士

【摘要】 随着现代科技的发展，电子技术几乎已经渗透到生产生活的各个领域。人们对稳定电源的需求量逐日增大。恒流源作为稳定电源的分支，在电源的研究领域中有着极其广阔的发展空间。特别指出，近年来随着半导体激光器（laser Diode，简称LD）在工业和医疗等领域的广泛应用，LD恒流驱动源的研究和生产，得到了许多厂商和科研单位的重视。为给20-75W半导体泵浦模块或连续大功率LD阵列提供恒流驱动源，本文设计并实现20A大功率恒流驱动器。根据LD对驱动源的设计要求，确定20A大功率恒流源的参数指标，进而提出系统设计方案。所设计的恒流驱动器的核心电路是基于负反馈系统的电压控制电流源（VCCS），以实现高稳定度的输出电流。为增强功率放大模块的大电流输出能力，设计了一种复合达林顿的电路拓扑结构。功放的输出级采用多只功率管并联电路结构，使总的输出电流由多个功率器件分担，从而增大驱动器的冗余度，提高系统可靠性。为避免电流集中效应对功率晶体管的影响，分别从功率晶体管的E-M方程和I-V特性的角度，分析了导致功率晶体管并联分流不平衡的原因，并针对这一问题提出了具体可行的解决办法，重点从理论上推导均流电阻的计算方法，并通过实验分析验证了所提出的方法的正确性。散热器的性能是保证功率器件稳定可靠工作的关键。为此，设计了一种新型散热器，降低散热器热阻，增强其散热性能。通过实验验证，所设计的散热器能够使功率放大模块的热量均衡传导，保证了恒流驱动器的可靠性以及工作寿命。通过对CCD-203A恒流驱动器样机的测试，所实现的参数指标为：最大输出电流Iomax=20.12A；输出电流控制灵敏度A_g=2.11A/V；输出电流稳定度<0.1％；纹波电流<50mA，各项参数指标满足设计要求。更多还原

【Abstract】 With the development of modern science and technology, electronic technologyhas penetrated into almost every area of industrial production and our daily life. Thedemand of stabilized power supply is increasing gradually. As a kind of stabilized powersupply, the constant current source has the extremely broad development space in thefield of power supply. Particularly, with the widely using of laser Diode (LD) inindustrial and medical fields in recent years, research and production on LD constantcurrent driver get the attention of many manufacturers and research institutes. The paperdesign and realize a kind of20Ahigh power constant current driver, in order to provideconstant-current driver source for the20-75W semiconductor pump module or thecontinual high efficiency LD arrays.The technical specification and the system design program of the20A high powerconstant current source are determined according to the requirement of driving sourcefrom LD. The core circuit of the proposed constant current driver, which is based onvoltage controlled current source (VCCS) of negative-feedback system, in order toachieve high stability of output current. A circuit topology of Darlington compositestructure is designed to enhance the large current output capability of power amplifiermodule.In the power module, the topological structure of paralleled power transistors isdesigned to endure heavier load current, and to improve the circuit’s redundancy andreliability. In order to avoid current concentration effect on the influence of the powertransistors, the paper analyzed the various factors which may cause current unbalancedamong the paralleled power transistors, from the perspective of the E-M equations andI-V characteristics of the power transistor, respectively. Some measures are put forwardfor constructing the power transistors’ parallel circuit. Concrete and feasible solutions have been proposed, focusing on the theoretically derivation of the current-sharingresistances calculation method, and verify the correctness of the proposed method fromexperimental analysis.Whether the high power constant current driver can works normally or not isdetermined by radiator’s performance. Therefore a new kind of radiator is designedthrough researching heat theory, to reduce thermal resistance and improve their thermalperformance. The designed radiators are demonstrated experimentally that the heat ofthe power amplifier module can conduct equally, which can ensure the reliability andworking life of the constant-current driver.Through prototype testing, the proposed20A high power constant current driversatisfies the requirements of the indicators. It demonstrates through experiments that themaximum output current Iomaxis20.12A, the control sensitivity A_gof output current is2.11A/V, the long-term stability is less than0.1％and the ripple current is less than50mA. Various parameters satisfy the design request.更多还原