This reference design demonstrates the TEA1721 as a -12 V and -3.3 V AC/DC SMPS converter that can provide 5 W into a load. The switch-mode converter operates in flyback mode at a maximum frequency of around 50 kHz. Over-current and short circuit protection are built in. Under no-load conditions, the power consumption of the flyback converter is around 20 mW. This application is typically suited for White Goods appliances and industrial applications.