Digital control and simulation of parallel current mode for Buck converter

Parallel current mode control algorithm for DC-DC converters is introduced in this paper. This control strategy is composed of two parallel terms: voltage term and current term which is calculated based on the input voltage, inductor current and output voltage. The new duty cycle algorithm requires only one multiplication, one division and three additions in digital implementation. The simulation results demonstrate that parallel current mode control has superior steady-state response over the conventional current mode control, and maintains a good dynamic response. A 400-kHz switching frequency Buck converter based on FPGA implementation shows that the new duty cycle control strategy is optimal for digital control.