The demo board is designed as an isolated 24 V, 5 V and 3.3 V AC/DC SMPS for supplying up to 5 W to a load. On the input side, single phase, 2-phase or 3-phase Universal Mains power can be connected. The switch-mode converter operates in flyback mode at a maximum frequency of around 50 kHz. Overcurrent and short-circuit protection are built in. The power consumption is below 50 mW under no-load conditions. EMI filtering and surge protection using TVS diodes is implemented in this circuit. This application is intended as a 3-phase low-power SMPS which is especially suited for 3-phase industrial and multi-phase e-metering SMPS applications.