The SSC9503 is a quasi-resonant PWM controller IC manufactured by Sanken Electric. It is designed for high-efficiency AC/DC power supplies and DC/DC converters. This IC integrates various protection features and control functionalities to ensure stable and reliable power supply operation, while minimizing external components.

Applications:

• Power supplies for LCD TVs
• Power supplies for LED lighting
• AC-DC adapters for laptops and other devices
• DC-DC converters in industrial equipment
• Offline power supplies

Features:

• Quasi-Resonant Operation: Achieves high efficiency and low EMI noise.
• Valley Switching: Further reduces switching losses.
• Burst Mode Operation: Improves efficiency at light loads by skipping switching cycles.
• Soft-Start Function: Reduces stress on components during startup.
• Overcurrent Protection (OCP): Protects the IC and power supply from excessive current.
• Overvoltage Protection (OVP): Prevents damage from voltage surges.
• Undervoltage Lockout (UVLO): Ensures proper operation at the correct voltage levels.
• Overload Protection (OLP): Shuts down the IC in case of overload conditions.
• Thermal Shutdown (TSD): Protects the IC from overheating.

Benefits:

• High Efficiency: Minimizes energy consumption and heat dissipation, contributing to a greener design.
• Low EMI Noise: Reduces interference with other electronic devices.
• Robust Protection: Comprehensive protection features ensure reliable and safe operation.
• Simplified Design: Integrated functionalities reduce the need for external components.
• Cost-Effective Solution: Provides an excellent balance of performance, features, and cost.

Additional Details:

The SSC9503 operates in quasi-resonant mode, which means it switches when the voltage across the MOSFET is at its minimum, resulting in reduced switching losses and lower EMI. Valley switching further enhances efficiency by synchronizing the switching action with the valleys of the resonant waveform. Burst mode operation allows for extremely low standby power consumption, making it ideal for applications that require high efficiency across a wide load range.

The SSC9503 typically requires external components, including a MOSFET, rectifier diode, and passive components, to create a complete power supply. The specific values of these components depend on the desired output voltage, current, and other operating parameters. Designers should consult the manufacturer's datasheet for detailed guidance on component selection and application circuit design.

Technical Specifications (Typical):

• Operating Voltage Range: 8.9V to 25V
• Switching Frequency: Varies based on application and component selection.
• Operating Temperature Range: -20°C to +115°C
• Package: DIP-18 or SOP-18