One of the key benefits of the TEA172x is the low no-load power consumption. This low no-load power level is made possible by a number of key features inside the product. First, start-up is realized by an integrated high-voltage start-up current source which is disabled in normal operation. This avoids external current consuming bleeder circuitry. Second, in no-load condition, the IC enters the energy save burst mode, which reduces the IC current consumption down to about 100 µA. Furthermore, output voltage sensing is done at primary side via the auxiliary winding of the transformer. As a result, no current-consuming opto-coupler and shunt regulator are needed at the secondary side. Last but not least, the switching frequency in no-load conditions is decreased significantly, minimizing the switching losses and reducing the total power consumption.