The Research Of Simulate Experiment Method On Semiconductor Laser Diode Driver's Unit Circuit

Semiconductor laser generator is a kind of device which has high power density and very high quanta efficiency. Its endurance ability to electronic impaction is so bad that a weak currency can induce great changes in light power outputs and parameters (for example: laser radio wave length, noise performance, mode flop )of device . And these changes directly endanger the safety in using device, so we have high request to the performance of semiconductor driver and safety protection in application. This thesis emulates the last level and protective circuit of semiconductor laser driver on the basis of the complement of the prophase hardware circuit design. Computer simulation is often used in validating design plan, forecasting system performance, detecting the latent problem of new products and estimating solution methods, and etc.. It can mainly solve two problems.: validating the veracity of the experiment result through analyzing designed circuit and adjusting parameters according to experiment result. So computer emulator can largely decrease the manual work, shorten design cycle and depress design cost. Semiconductor laser driver computer emulator technology can detect circuit performance of prophase design circuit and bring forward method of improving the performance. This thesis, using protel99SE as emulator software, puts up the emulator experiment of the main cell circuit of semiconductor laser driver. The virtue of this software is that it integrates circuit emulator function which is compatible with PSPICE and has powerful emulator function, precision emulator structure, relatively clear output wave and convenient and intuitionistic operation. Here, we, using analysis methods including static state working point, winking state, DC scanning, temperature scanning, noise and etc. which are provided by protel99SE, emulate and analyze the cell circuit and study the cell circuit experiment method. In last level circuit (constant currency driving circuit ), through electrics feedback control loop directly providing the efficiency control of driving currency level, we can get the stability of lowest currency warp and highest LD outputs. So in Protel99SE , designing emulator electrics schematic and selecting suitable experiment method ( emulating analysis method ) can detect the veracity and performance of circuit. Due to the significant position of constant currency driving circuit in driver circuit, thesis experiments in manifold emulator analysis methods. 1) Use wink state analysis method to validate if the output currency is invariableness relative to input signal. From the emulator wave, the circuit parameter selecting is exact, and output currency is invariableness. 2) Temperature scan: result data indicates that output currency changes very little when environment temperature increase every 10oC . 3) DC scan: Verifying the output currency variety law in the range of 0.1-10V. And result is in accord with theory analysis. 4) Parameter scan: Changing R1, and observing the variety of the output currency. From output result, when output currency has been confirmed, we can choose the value of R1, according to norm voltage. The experiment method can save design time and experiment steps, so hardware experiment can't compare with it. 5) Noise analyze: detecting output noise level when input is intermingled differ frequency noise signal. In practical hardware experiments, input signal may intermingle some disturbing signal. From output, the noise level is not high, especially high frequency noise. This result can't be get through hardware experiment. software experiments of constant currency drive circuit above detect the veracity of circuit parameter chosen, finish project that is unappeasable in hardware experiment and farther verify the veracity of the circuit design. It can satisfy the function in the whole driver circuit and output currency is invariableness and has high stability. In prophase designing, Designer offered several schemes for this driver in view of protection problem. According to circuit protection principle, thesis...