The TOPSwitch-JX is a highly integrated monolithic off-line switcher IC designed for off-line power supplies. TOPSwitch-JX integrated circuits enable design of power supplies up to 244 W, while providing high effciency under all load conditions. TOPSwitch-JX also provides very good performance at low load and during standby (no-load) operation. The TOPSwitch-JX family allows the designer to easily meet effciency requirements for the latest energy-effciency standards. Innovative and proprietary features enable design of compact and cost effective switching power supplies while reducing overall design cycle time and system cost. The TOPSwitch-JX family also enables the design of power supplies with robust functionality and provides enhanced safety features such as output overvoltage protection, overload power limiting and hysteretic thermal protection. Transient Suppression Techniques for TOPSwitch Power Supplies Application Note AN-20 Introduction U 1.0 Front Time T1 = 1.67 x T = 1.2 s ± 30% 0.9 AC power mains occasionally have transient surge voltages. ……