The present disclosure relates to a DC-DC converter (10), comprising a first DC port (10A) connectable to a DC source (B), a second DC port (10B) with a positive terminal (PT), a midpoint terminal (MT) and a negative terminal (NT) connectable to a DC bus (4). A first capacitor (C1) is connected between the positive terminal (PT) and the midpoint terminal (MT) and a second capacitor (C2) is connected between the midpoint terminal (MT) and the negative terminal (NT). The DC-DC converter (10) comprises a first switching circuit (20), a second switching circuit (40) and a resonant circuit (30) connected between the first switching circuit (20) and the second switching circuit (40). The second switching circuit (40) comprises a first switch (Q1), a second switch (Q2), a third switch (Q3), and a fourth switch (Q4).