摘要 |
The invention relates to a DC-DC converter and a power supply unit formed thereby, with which a DC input voltage (Vdc) may be converted into two DC output voltages (U1, Usb) via a resonant switched-mode power supply. Via a circuit stage (M1, M2), a control circuit (C) generates a first AC voltage (VAC), which is converted via two resonant circuits with different transmission behavior and two rectifiers (G1, Gsb) in frequency-dependent manner into DC output voltages (U1, Usb). To achieve a standby mode, in which the first DC output voltage (U1) is designed to be very low and hardly any power is drawn on the output side, a second, thinner auxiliary circuit stage (M3, M4) is provided, which is coupled to the resonant circuits via an inductor (L2). The current consumption of the circuit in standby mode may be reduced considerably by appropriate dimensioning.
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