Fairchild FSEZ1317NY 6W LED Lighting Driver Solution

Fairchild's FSEZ1317NY is a third-generation primary-side regulation (PSR) and highly integrated PWM controller with standby power consumption below 300mW, high-voltage start-up, minimal external components, constant voltage (CV) and constant current (CC) control without secondary feedback circuit, and a PWM fixed frequency of 50kHz. It is mainly used in chargers for mobile phones, cordless phones, PDAs, digital cameras, etc., replacing linear transformers and RCC switching power supplies (SMPS). This article introduces the main features of FSEZ1317, functional block diagram, simplified PSR flyback converter circuit diagram, high-voltage start-up circuit diagram, and the main features, circuit diagram, and transformer circuit diagram of the 6W LED lighting driver.

FSEZ1317: Primary-Side-Regulation PWM with POWER MOSFET Integrated

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, TRUECURRENT™, of FSEZ1317 enables precise CC regulation and simplified circuit design for batterycharger 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 provides off-time modulation to linearly decrease PWM frequency under light-load conditions. Green mode assists the power supply in meeting power conservation requirements.

By using the FSEZ1317, a charger can be implemented with few external components and minimized cost.

FSEZ1317 main features:

 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: 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

 VDD Over-Voltage Protection with Auto Restart

▪ VDD Under-Voltage Lockout (UVLO)

▪ Gate Output Maximum Voltage Clamped at 15V

▪ Fixed Over-Temperature Protection with Auto Restart

▪ Available in the 7-Lead SOP and DIP Packages

FSEZ1317 Applications:

▪ Battery chargers for cell phones, cordless phones, PDA, digital cameras, power tools, etc.

▪ Replaces linear transformers and RCC SMPS

Figure 1. FSEZ1317 Functional Block Diagram

Figure 2. FSEZ1317 Simplified PSR Flyback Converter Circuit Diagram

Figure 3. FSEZ1317 High Voltage Startup Circuit Diagram

Figure 4. FSEZ1317 Typical Application Circuit

6W LED Lighting Driver

The following reference design supports inclusion of FSEZ1317NY in design of LED illumination.

6W LED Lighting Driver Main Features:

Constant-Voltage (CV) and Constant-Current (CC) Control without Secondary- Feedback Circuitry

Built in 700V/1A MOSFET

Low EMI through Frequency Hopping

Low Power Consumption in Standby

Protection Functions: UVLO, Over-Voltage, Over-Current, and Over-Temperature

Figure 5. 6W LED Lighting Driver Circuit

Figure 6. 6W LED Lighting Driver Transformer Circuit