Small-signal modeling and control of the quasi-square-wave boost converter

Sampled-data techniques are used to examine the dynamic characteristics and closed-loop performance of the quasi-square-wave boost converter, Direct duty-ratio control and current-mode control are considered, With direct duty-ratio control, the system poles remain well damped under all load conditions, and there is no zero in the control-to-output transfer function, Good closed-loop performance Is therefore achieved, Under current-mode control, the requirement for a stabilizing ramp is seen to depend on load conditions, and the achievable voltage control-loop bandwidth is smaller than that using direct duty-ratio control, however, there is a significant reduction in the magnitude of the de source to output-voltage frequency response.