A low-cost and flexible architecture of digitally controlled DC-DC converter to improve dynamic performance

Abstract

One type of DC-DC converters is dual transistor forward converter. In this article, a low-cost architecture ofa digital controller for dual transistor forward converter is presented. This architecture is designed by using the finite setmodel predictive control technique. Based on this approach, a low-cost fixed-point arithmetic architecture with minimumfunctional units is presented to find the optimum switching time at each sampling point. Charge balance control methodis utilized to improve the dynamic performance of the transient response. The proposed architecture is implementedand realized by using a field-programmable gate array (FPGA) platform to evaluate the precision of the fixed-pointcalculation. Several cases for different loading conditions for different word lengths are practically investigated and theproposed digital controller shows a minimum voltage overshoot–undershoot and short settling time under load-changingsituations. Compared with other controllers, the presented work provides a better dynamic performance and lowerimplementation cost.