The LD7400GS is a current mode PWM controller designed for offline flyback converter applications. It is optimized for high performance, low standby power, and cost-effectiveness. This Leadtrend controller integrates multiple features to simplify the design of power supplies while ensuring reliability and high efficiency.

Applications:

• Adapters for mobile devices, such as smartphones and tablets.
• Power supplies for set-top boxes.
• Chargers for various battery-powered devices.
• Standby power supplies for home appliances.
• Open-frame power supplies.

Features:

• Current Mode PWM Control: Provides excellent line regulation and load regulation performance.
• Low Startup Current: Reduces power losses during startup and enables faster startup times.
• Cycle-by-Cycle Current Limiting: Protects the external MOSFET from overcurrent conditions on a cycle-by-cycle basis.
• Over Voltage Protection (OVP): Prevents damage to the load by limiting the maximum output voltage.
• Over Load Protection (OLP): Protects the power supply from excessive current draw due to overload conditions.
• Short Circuit Protection (SCP): Shuts down the power supply in the event of a short circuit at the output.
• Under Voltage Lockout (UVLO): Ensures stable operation and prevents malfunction at low input voltages.
• Frequency Jittering: Reduces EMI and improves compliance with EMC standards.

Benefits:

• High Efficiency: Minimizes power dissipation, leading to lower operating temperatures and reduced energy consumption.
• Enhanced Protection: Offers comprehensive protection features to ensure reliable operation and prevent component failures.
• Simplified Design: Reduces the number of external components required, making the design process easier and faster.
• Low Standby Power Consumption: Helps meet stringent energy efficiency standards.
• Improved EMI Performance: Reduces electromagnetic interference, ensuring stable operation in noisy environments.

Additional Details:

The LD7400GS employs a fixed-frequency PWM scheme for stable operation and predictable performance. It includes built-in slope compensation to prevent subharmonic oscillation at higher duty cycles. The device is available in a compact package suitable for space-constrained applications. The integrated protection features enhance the robustness and reliability of the power supply. The precise control offered by the current-mode architecture guarantees stable and efficient power delivery over a wide range of input voltages and output loads. The IC is designed to be compatible with various external components, offering design flexibility. The soft-start function minimizes stress on the power MOSFET and secondary diode during startup, enhancing the overall reliability of the system. The device is optimized for use in cost-sensitive applications without compromising performance or reliability.