This third-generation Primary Side Regulation (PSR) and highly integrated PWM controller provides several features to enhance the performance of low-power flyback converters. The proprietary topology, TURECURRENT™, of FAN103 enables precise CC regulation and simplified circuit for battery charger applications. A low-cost, smaller and lighter charger results as compared to a conventional design or a linear transformer.

To minimize standby power consumption, the proprietary green-mode function provides off-time modulation to linearly decrease PWM frequency under light-load conditions. This green mode assists the power supply in meeting the power conservation requirement.

By using the FAN103, a charger can be implemented with few external components and minimized cost. A typical output CV/CC characteristic envelope is shown in Figure 1.

• Low Standby Power Under 30mW
• High Voltage Startup
• Fewest External Component Counts
• Constant-Voltage (CV) and Constant-Current (CC) Control without Secondary-Feedback Circuitry
• Green-Mode Function: Linearly-Decreasing PWM Frequency
• Fixed PWM Frequency at 50kHz with Frequency Hopping to Solve EMI Problem
• Cable Compensation in CV Mode
• Peak-Current-Mode Control in CV Mode
• Cycle-by-Cycle Current Limiting
• V_DD Over-Voltage Protection with Auto Restart
• V_DDUnder-Voltage Lockout (UVLO)
• Gate Output Maximum Voltage Clamped at 15V
• Fixed Over-Temperature Protection with Auto Restart
• Available in the 8-Lead SOP Package

• Battery chargers for cellular phones, cordless phones, PDA, digital cameras, power tools
• Replaces linear transformer and RCC SMPS