The ICE3AR4780JG it is running at 100 kHz, implemented with brownout feature, installing 800 V CoolMOS™ with startup cell. The CoolSET™ F3R80 provides good voltage margin of MOSFET, lowest standby power, selectable burst level, reduced output ripple during burst mode, reliable output with brownout feature, accurate maximum power control for both maximum power and burst power, low EMI with frequency jittering and soft gate drive, etc.