Proc. SPIE. 7156, 2008 International Conference on Optical Instruments and Technology: Optical Systems and Optoelectronic Instruments
KEYWORDS: Infrared imaging, Digital signal processing, Clocks, Switching, Imaging systems, Interference (communication), Power supplies, Field programmable gate arrays, Infrared radiation, Analog electronics
Existing switching mode power supply solutions cause unacceptable self-pollution within the infrared imaging system.
The band unlimited PWM signal will be coupled to the input of ADC, and then be sampled. High order harmonics are
aliased down to the frequency band of the image signal. With the use of the digital PWM controller, the switching
frequency can be precisely synchronized with the ADC sampling clock. The predominant parts of the noise signal will be
down converted into the DC signals and eliminated by image processing units. The noise immunity principle was tested
and proved on an infrared image capture system.