The FAN604H is an advanced PWM controller aimed at achieving power density of ≥10W/in3 in universal input range AC/DC flyback isolated power supplies. It incorporates Quasi-Resonant (QR) control with proprietary Valley Switching with a limited frequency variation. QR switching provides high efficiency by reducing switching losses while Valley Switching with a limited frequency variation bounds the frequency band to overcome the inherent limitation of QR switching. FAN604H features mWSaver? burst mode operation with extremely low operating current (300 μA) and significantly reduces standby power consumption to meet the most stringent efficiency regulations such as Energy Star’s 5-Star Level and CoC Tier II specifications.FAN604H includes several user configurable features aimed at optimizing efficiency, EMI and protections. FAN604H has a wide blanking frequency range that improves light load efficiency and eliminating audio noise for adaptive application. It incorporates user-configurable constant current reference, which allows controlling the maximum output current from primary-side, thereby optimizing transformer design to improve the overall efficiency. It also includes several rich programmable protection features such as over-voltage protection (OVP), precise constant output current regulation (CC).

• Quasi-Resonant Switching Operation with Wide Blanking Time Range
• Constant Current Reference (CCR) to Limit the Maximum output Current
• mWSaver? Technology for Ultra Low Standby Power Consumption (
• Programmable Over-Temperature-Protection through External NTC Resistor
• Built-In and User Configurable Over-Voltage Protection (OVP), Under-Voltage, Protection (UVP) and Over-Temperature Protection (OTP)
• Forced and Inherent Frequency Modulation of Valley Switching for Low EMI Emissions and Common Mode Noise