ICE2QS03G is a quasi-resonant PWM controller optimized for off-line switch power supply. The digital frequency reduction with decreasing load enables a quasi-resonant operation till very low load. As a result, the overall system efficiency is significantly improved compared to other conventional solutions. The active burst mode operation enables ultra-low power consumption at standby mode with small and controllable outputvoltage ripple. Based on the BiCMOS technology, the product has a wide operation range (up to 25V) of IC power supply and lower power consumption. The numerous protection functions give a full protection of the power supply system in failure situations. All of these make the ICE2QS03G an outstanding controller for quasiresonant flyback converter in the market.