【作者】 杜海涛；

【导师】 邹建；

【作者基本信息】 重庆大学 ， 光学工程， 2011， 硕士

【摘要】 半导体光源是由以半导体材料构成的PN结为工作物质的半导体器件,它以注入电流为激励源。这种器件的量子效率极高,但是它对电冲击的承受能力很弱,弱小的电流变化都可能会导致器件参数发生变化,电流突变甚至会导致半导体器件的老化或损坏,因此驱动电流的稳定性对器件的输出有着直接的影响。光源器件的工作物质是PN结,对温度极其敏感,温度变化会直接影响到半导体光源器件的阈值电流及输出光功率的稳定性,严重破坏半导体光源的工作特性。为了能使半导体光源正常工作,必须控制半导体光源器件的工作温度。为了使输出的光功率稳定,本文对自动功率控制方法进行了研究,并采用与恒流源、自动温度控制相结合的方式来实现光功率的稳定输出。首先,本文对半导体光源的工作原理和特性进行了介绍,在大量查阅了国内外相关参考文献的前提下,分析了半导体光源对驱动电源的要求,并对半导体光源的光控和温控理论进行了分析,在此基础上设计了基于ARM高精度的半导体光源驱动控制器。它包括数字化恒流源驱动电路,光电检测电路和温控电路等。恒流源与光电检测电路构成了光控电路,恒流源由ADuC7026微控制器及其DAC、慢启动电路和V/I转换电路等组成。它的整体设计思路是利用高性能斩波稳零运算放大器和负反馈原理,使整个闭环系统处于动态的平衡中,从而达到稳定输出电流的目的。温控电路利用专用温度控制芯片ADN8830对TEC进行PID闭环自动控制,采用半导体光源组件内部的热敏电阻作为温度传感器。其次,设计了数字化控制系统的相关软件。具体包括系统的初始化,DA转换、AD转换、数字化光功率控制的实现、温度的设定和温度、光功率以及驱动电流的采集和显示。最后,本文通过实验获得了驱动电流的稳定度、温度的稳定度和在有无光控和温控的条件下输出光功率的稳定度,验证了前面理论分析的正确性和可行性。证明了本文设计的驱动控制器满足我们的要求。该半导体光源驱动控制器可以提供高精度的光源,具有广泛的应用前景。更多还原

【Abstract】 Semiconductor illuminant is a semiconductor device which takes PN knot as working material and it takes inject current as excitation.It is a kind of device with high and efficiency power.Its ability to withstand the impact of current is very weak. Semiconductor illuminant is a current drive device. Weak drive current and will lead to its changing of optical power or device parameters. Even current mutations can lead to damage of semiconductor devices. So the stability of the drive current has thedirect influence on the light power. The operationmaterial of semiconductor illuminant is PN knot,which is very sensitive to temperature.Temperature change will directly affect the semiconductor illuminant threshold current and the stability of optical power. Even seriously damage the working characteristic of semiconductor illuminant. In order to work well,the working temperature of semiconductor illuminant must be under the control.In this paper, the study mainly on constant-current source、optical power control and temperature control.First of all,this paper introduces the principle and characters of semiconductor illuminant、analyses the necessity of designing a special driver power with high quality and analysis the theory of optical power control and temperature control by referring a lot of domestic and foreign references.Designed the semiconductor illuminant driver based on ARM. It includes Digital constant-current source driver circuit、Photoelectric detection circuit and temperature control circuit. Optical power control circuits are constituted of constant-current source circuit and photoelectric detection circuit. The constant-current circuit is constituted of ADuC7026 micro controller and its DA converters、slow start-up circuit and V/I convert circuit.The whole design idea is to use Super chopper-stabilized amplifier and principle of negative feedback to stabilize output current which obtains the lowest current error and the highest current stability. TEC was controlled automatically using closed-loop PID by ADN8830.The thermistor internal of Semiconductor illuminant components is used as temperature sensor. Designed the software of the digital control system,which includes system initialization, DA conversion、AD conversion、optical power control and temperature、optical power and drive current acquisition and display.In the last part of the paper,the stability of the drive current、operating temperature and optical power under the control of temperature and optical power or no are validated by experiments.It proves that the semiconductor illuminant driver designed in this paper can work well. Under the control of the semiconductor illuminant driver, we can obtain very stable optical power.更多还原