PLANAR MAGNETIC COMPONENT

A planar magnetic component (PE) is arranged on a circuit board (CB1) of a resonant converter (100), and the resonant converter (100) includes a primary-side circuit (1A) and a secondary-side circuit (3A). The planar magnetic component (PE) includes an inductor trace (Tl), an inductor iron core (C L), and a current transformer trace (Tea, Tcb). The inductor trace (Tl) is arranged on the primary-side circuit (1A) and formed one layer board of the circuit board (CB1) to serve as a resonant inductor (Lr) coupled to the primary-side circuit (1A). The inductor iron core (C_L) includes a core pillar (C_LC), and the core pillar (C_LC) penetrates a through hole (H3) of the circuit board (CB1), and the inductor trace (Tl) surrounds the through hole (H3). The current transformer trace (Tea, Tcb) is formed on the circuit board (CB1) to serve as a current transformer coil (52A, 52B) coupled to the resonant inductor (Lr). The current transformer trace (Tea, Tcb) surrounds the through hole (H3) to form a common-core structure that shares the inductor iron core (C_L).