Nonlinear average current mode control for a DC-DC Buck converter

In this paper the nonlinear average current control for a DC-DC buck converter is presented in both continuous conduction mode (CCM) and discontinuous conduction mode (DCM). The outer voltage control loop uses a PI controller. In the present control scheme, switch current is being sensed instead of inductor current. Sensing of the switch current instead of inductor current is particularly attractive for low power applications due to its improved efficiency and the possibility to integrate the control circuitry with the power switch. Average of inductor current, output voltage along with line and load regulation is being controlled using this control scheme. The control method requires no current compensator design. A 10 W, 100 kHz buck converter with simulation results are presented.