Title :
Digital closed-loop EMI reduction in switched mode power supplies using adaptive spread spectrum technique
Author :
Poshtkouhi, Shahab ; Trescases, Olivier
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Toronto, Toronto, ON, Canada
Abstract :
Using a variable frequency, or spread spectrum clock in switched-mode power supplies is a popular method for reducing EMI in noise-sensitive applications. A system that operates with a fixed frequency-spread must inevitably be over-designed to compensate for the uncertainties in the parasitic components, as well as aging and temperature effects. In this work, a self-calibrated, adaptive spread spectrum system is simulated using an integrated boost converter in a high voltage 0.35 μm CMOS technology. The converter operates with a programmable spread of fs = 100-350 kHz. The EMI spectrum is calculated from the sampled input current using a short-time FFT and compared with programmable limits based on EMC regulations. The spread is actively minimized under different conditions, while meeting EMI targets.
Keywords :
CMOS integrated circuits; electromagnetic compatibility; electromagnetic interference; interference suppression; switched mode power supplies; CMOS technology; EMC; FFT; adaptive spread spectrum technique; digital closed-loop EMI reduction; frequency 100 kHz to 350 kHz; switched mode power supplies; Converters; Electromagnetic compatibility; Electromagnetic interference; Field programmable gate arrays; Modulation; Switched-mode power supply; Switching frequency;
Conference_Titel :
Control and Modeling for Power Electronics (COMPEL), 2010 IEEE 12th Workshop on
Conference_Location :
Boulder, CO
Print_ISBN :
978-1-4244-7462-2
Electronic_ISBN :
978-1-4244-7461-5
DOI :
10.1109/COMPEL.2010.5562374