HFC0512 Fixed-Frequency Flyback Controller SOIC8

HFC0512 Fixed-Frequency Flyback Controller SOIC8

The HFC0512 is a fixed-frequency, current- mode controller with internal slope compensation.

Key Specifications

Features

• Fixed-Frequency, Current Mode Control with Internal Slope Compensation
• Frequency Foldback Down to 27kHz at Light Loads
• Burst Mode for Low Standby Power Consumption, Meeting EuP Lot 6 Standard
• Frequency Jittering for Reduced Electromagnetic Interference (EMI)
• Adjustable Over-Power Compensation
• Internal High-Voltage Current Source
• VCC Under-Voltage Lockout (UVLO) Protection with Hysteresis
• Brownout Protection via the HV Pin
• Overload Protection (OLP) with Configurable Delay
• Thermal Shutdown (Auto-Restart with Hysteresis)

Typical Application Circuit

Applications

• AC/DC Power for Small and Large Appliances
• AC/DC Adapters for Notebook Computers, Tablets, and Smartphones
• Offline Battery Chargers

Design Notes

• The PFC inductor must support the maximum duty cycle at the lowest line voltage, which is where saturation risk peaks.
• High-voltage startup and X-capacitor discharge paths dominate no-load standby loss; verify them against the efficiency target.
• Leakage inductance and the RCD clamp set the turn-off loss — snubber values are a thermal trade-off, not a fixed recipe.
• Synchronous rectification timing must track the primary switching; a mistimed SR FET conducts through its body diode and fails hot.

Common Questions