The STRF6267 is a quasi-resonant regulator IC manufactured by Sanken Electric. It's designed for SMPS (Switching Mode Power Supply) applications, particularly in devices requiring efficient power conversion and reduced noise. This IC integrates a power MOSFET and control circuitry to simplify power supply designs and improve overall system performance.

Applications

• Power supplies for LCD TVs
• Adapters for various electronic devices (e.g., laptops, printers)
• Auxiliary power supplies in industrial equipment
• Consumer electronics power supplies
• OA equipment power supplies

Features

• Quasi-Resonant Operation: Enables high efficiency and low EMI noise.
• Integrated Power MOSFET: Reduces external component count and simplifies design.
• Built-in Startup Circuit: Eliminates the need for external startup resistors.
• Protection Features: Includes overcurrent protection (OCP), overvoltage protection (OVP), and thermal shutdown (TSD).
• Low Standby Power Consumption: Meets energy-saving requirements.
• Soft-Start Function: Reduces stress on components during startup.
• Frequency Foldback Function: Improves efficiency at light loads.

Benefits

• High Efficiency: Quasi-resonant operation minimizes switching losses, leading to improved efficiency and reduced heat generation.
• Reduced EMI Noise: Quasi-resonant operation lowers electromagnetic interference, simplifying system compliance.
• Simplified Design: Integration of power MOSFET and control circuitry reduces external component count and design complexity.
• Enhanced Reliability: Built-in protection features ensure robust operation and prevent damage from abnormal conditions.
• Energy Savings: Low standby power consumption helps meet energy efficiency standards and reduces operating costs.
• Compact Size: Integration allows for smaller power supply designs.

Additional Details

The STRF6267 operates by detecting the voltage and current of the MOSFET and optimizing the switching frequency to reduce losses. The integrated MOSFET typically has a breakdown voltage suitable for off-line power supplies (e.g., 650V or higher). The IC also incorporates a gate drive circuit specifically tuned to the integrated MOSFET. The overcurrent protection (OCP) is generally implemented using a current sensing resistor and a comparator. The overvoltage protection (OVP) monitors the output voltage and shuts down the IC if it exceeds a preset threshold. Thermal shutdown (TSD) protects the IC from overheating. The IC's package is designed for efficient heat dissipation.