Professional IC Distribution & Technical Solutions

The L6569A is a current-mode primary controller IC manufactured by STMicroelectronics, designed for offline flyback converters. Below are its key specifications, descriptions, and features:

Specifications:

• Input Voltage Range: Up to 600V (high-voltage startup)
• Operating Frequency: Adjustable up to 300 kHz
• Output Power: Up to 15W in DIP-8 package (depending on design)
• Startup Current: < 50 µA
• Quiescent Current: < 3 mA
• Peak Driving Current: ±400 mA (for MOSFET gate drive)
• Protections: Overvoltage (OVP), overload (OLP), undervoltage lockout (UVLO)

Description:

The L6569A is a PWM controller optimized for quasi-resonant (QR) operation in flyback converters, improving efficiency by enabling valley switching. It includes a high-voltage startup circuit, reducing external component count. It operates in transition mode (TM) for power factor correction (PFC) applications.

Features:

• Quasi-Resonant Operation: Reduces switching losses by enabling zero-voltage switching (ZVS).
• Current-Mode Control: Ensures cycle-by-cycle current limiting.
• Adjustable Frequency: External resistor sets maximum switching frequency.
• Line Voltage Feedforward: Improves input regulation.
• Soft Start: Reduces inrush current.
• Latched or Auto-Recovery Protections: Configurable for OVP/OLP.
• Low Power Consumption: Enhances efficiency in standby mode.

The L6569A is commonly used in AC/DC adapters, LED drivers, and auxiliary power supplies.

(Source: STMicroelectronics datasheet)