The SG6859TZNL is a highly integrated PWM controller from Fairchild/ON Semiconductor, specifically designed for offline flyback converter applications. It incorporates a current mode PWM controller and various protection features to provide a cost-effective and reliable solution for power supply designs requiring low standby power and high efficiency. This device is frequently used in adapters and chargers for various consumer electronics.

Applications

• AC/DC Adapters for Consumer Electronics (e.g., set-top boxes, DVD players)
• Battery Chargers for Mobile Devices (e.g., smartphones, tablets)
• Standby Power Supplies
• LED Lighting Power Supplies
• Small Power Adapters for portable devices

Features

• Current Mode PWM Control: Provides stable operation and excellent line/load regulation.
• Low Startup Current: Minimizes power consumption during startup, improving energy efficiency.
• Frequency Jittering: Reduces EMI emissions by spreading the switching frequency over a range.
• Over-Temperature Protection (OTP): Protects the device from thermal damage caused by overheating.
• Over-Voltage Protection (OVP): Prevents the output voltage from exceeding safe limits, protecting the connected load.
• Over-Current Protection (OCP): Limits the output current to protect the device and the load from excessive current draw.
• Under-Voltage Lockout (UVLO): Ensures reliable startup and prevents erratic operation due to low input voltage.
• Open-Loop Protection (OLP): Protects the power supply in the event of a feedback loop failure.
• Soft-Start Function: Reduces stress on components during power-up, enhancing overall system reliability.
• Cycle-by-Cycle Current Limiting: Provides fast and accurate current limiting, protecting against short-circuit conditions.

Benefits

• High Efficiency: Minimizes power losses for energy-efficient operation.
• Compact Design: Integrated features reduce board space requirements.
• Enhanced Reliability: Comprehensive protection features ensure robust and stable performance.
• Simplified Design: Requires fewer external components, simplifying the design process.
• Improved EMI Performance: Frequency jittering minimizes electromagnetic interference, reducing the need for additional filtering components.
• Cost-Effective Solution: Integrated features contribute to a lower overall system cost.
• Low Standby Power Consumption: Meets stringent energy efficiency requirements for standby power consumption.

Additional Details

The SG6859TZNL typically operates at a fixed switching frequency, optimized for efficiency and EMI reduction. It usually comes in an SOP (Small Outline Package). Detailed specifications, including voltage and current ratings, switching frequency, and thermal characteristics, can be found in the device's datasheet. This device is designed to comply with international safety and energy efficiency standards, such as Energy Star and ErP regulations.