The Semiconductor Laser Power Supply Based On DSP

With rapidly growing the development of laser technology and microelectronics in 21th century, laser power supply also has been brought great changes, from pure analogous circuit to combining with SCM and DSP. However, the new developing trend of laser power supply is digital, high frequency, intelligent. Although SCM is able to control current and temperature of laser power supply, nowadays precision of that can not be fit for the real needs, limited of its velocity and function. Actually, many ideas can become true, if with the high-speed processing and calculating capability of DSP.This article makes semiconductor laser as the research object, which is a study of the laser power on digital and intelligent, with the United States specifically for the control field TI's DSP chip TMS320F2812 as control core. Making use of high performance calculating power and microprocessor digital control functions required, ample peripheral of DSP chip and function generating PWM waveform and peripheral circuits are integrated into one chip, matching the external expansion of memory chips and high-precision D/A chip. Comparing with the current power control system, the number of hardware reduces significantly, integration improves obviously.First of all, determine the diode laser driver power supply under the technology of DPSSL (Diode Pump Solid State Laser) as the study subject, analysis the working principle of semiconductor lasers and requirements, to obtain the laser power to design performance indicators and parts requirements.Secondly, according to the specific requirements of pulsed work, determine the technical implementation plan of the key components of the power supply, design the corresponding hardware circuits and software programs, use the power MOSFET as a power device, apply DSP to real-time control. Make use of feedback control theory to achieve the automated control, the output pulse current amplitude, pulse width and repetition rate are adjustable.Again, apply DSP's PWM output and powerful computing capability to design a semiconductor temperature control system, Put to use digital temperature sensor DS18B20 and semiconductor cooler (TEC), its high precision, rapid speed, small size to make the semiconductor laser working at a fixed temperature.Finally, make the testing analysis for laser power designed and the corresponding system to draw conclusions. The power completed development is stable and reliable in operation, reached predetermined performance specifications.