Simple hardware implementation of an adaptive mixed signal current programmed mode control for near minimum deviation transient response

This paper introduces a practical auto-tuned controller achieving near minimum deviation of the output voltage while using mixed-signal current programmed mode (CpM) implemented with very simple digital hardware. Compared to most time optimal and minimum deviation control methods, this method does not rely on fast current sensing and/or valley point detection, is unaffected by components variations, and requires no complex calculations. These advantages are obtained by utilizing a very simple control law requiring only a single multiplication of the measured capacitor voltage deviation value. A 12 V to 3.3 V/ 5 A buck converter prototype operating at 500 kHz has been implemented to show the effectiveness of this controller. Experimental results confirm a one switching cycle recovery of the inductor current to the new steady state value and practically minimum deviation of the output voltage.