Comparative study of hysteretic controllers for single-phase voltage regulators

A comparative study of hysteretic controllers for single-phase voltage regulators used in low-voltage applications is presented. The voltage-mode (VM) and current-mode (CM) control schemes considered here are designed with identical specifications. The regulator performance is evaluated in aspects such as load transient response, switching frequency design and component tolerance effects. Other aspects such as complexity and cost are also considered. Experimental results are reported in order to validate the theoretical predictions. Essentially the study demonstrates that: (1) both VM and CM controllers exhibit high performance for nominal power components, (2) the operation of the CM controller is extremely robust with respect to power-component tolerance and (3) the VM controller is a simple, low-cost control solution.