Self-tuning mixed-signal optimal controller with improved load transient waveform detection and smooth mode transition for DC-DC converters

A hardware efficient optimum-deviation voltage mode controller with a fast and noise-insensitive detection of the key voltage waveform points during load transients is introduced. To reduce the effects of noise and delays on the detection, a two extreme point detector with a voltage tracking window is introduced. In addition, an on-line algorithm for the compensation of load-dependent duty ratio variations effecting stability of optimal controllers is developed. The effectiveness of the system is verified with a 12V-to-1.6V/50 W, 500 kHz buck converter demonstrating about 30% smaller voltage deviation compared to the conventional optimal controller.