Design Of Signal Generator Based On USB And Development Of Laser Source In Laser Ultrasonic System

The dissertation is supported by the project of on-line quality inspection for sheet with laser ultrasonic. Improving stability of laser power is one of the key techniques in laser ultrasonic or fiber sensor system. Based on the characteristics of LD and the source requests of laser ultrasonic system, a temperature control circuitry, a power control circuitry and a pulse driver are designed, produced and adjusted with specific integrated chip so that the circuitry is cheap, simple and adjustable.In addition, a laser ultrasonic signal generator is designed based on USB2.0 in the conception of virtual instrument. This dissertation brings forward a collectivity design idea for the waveform generator, and analyses the structure of Digital-to-Analog converter and the characteristics of the USB controller core EZ-USB FX2. Based on the analysis of the principle of GPIF and Endpoint Buffers, a design for GPIF interface is brought forward, which reduces circuit frame, breaks through bandwidth bottleneck, incarnates specialty of USB2.0 high speed.