CURRENT MODE CONTROL METHOD USED FOR LLC RESONANT DC-DC CONVERTER SUITABLE FOR PORTABLE APPLICATIONS

In this paper, current mode control with Pulse-Frequency Modulation (PFM) is addressed to improve the dynamic performance of LLC resonant DC-DC converters irrespective of its operating conditions. In order to improve the dynamic performance and the noise immunity, the addressed control method employs an additional feedback from the current of the resonant tank with an integrator-type compensating amplifier. In this paper, the required design guide lines along with simulation studies are presented for current mode control using PFM. Design of the converter uses Fundamental Harmonic Approximation (FHA) with highest gain adjustment. Finally, a prototyp