A high number of poles varying with operating conditions makes the controller design for LLC resonant dc-dc converter challenging. A high bandwidth controller is essential for fast transient response and a high degree of input disturbance rejection is required to reduce the input filter size. This article proposes a new control architecture utilizing output diode current measurement that essentially reduces the control-to-output transfer function for an LLC resonant converter to a single order and provides a very high degree of input voltage disturbance rejection with only a minimal increase in control loop complexity.