Overview

The CX7503BCD is a high-performance primary-side power chip with a built-in high-voltage power MOS transistor, featuring high-precision constant voltage and constant current output in a quasi-resonant mode. This product enables the design of high-performance AC-DC switching power supplies with fewer external components and lower system cost. The CX7503BCD provides comprehensive and excellent intelligent protection functions, including cycle-by-cycle overcurrent protection, soft start, chip over-temperature protection, output over-voltage protection, VDD under-voltage lockout protection, and VDD over-voltage lockout protection. The CX7503BCD delivers precise constant voltage and constant current (CV/CC) output without the need for optocouplers, secondary-side control circuits, or loop compensation circuitry, while maintaining good stability. It features excellent output voltage regulation capability, high average efficiency, and standby power consumption of less than 75mW. The CX7503BCD integrates an output line loss compensation function, which can be adjusted by modifying the FB resistor divider values. The chip's unique PWM/PFM operating mode minimizes audio energy, ensuring no audio noise across the full load range. The CX7503BCD is available in a DIP7 package, providing an excellent design platform for cost-effective flyback switching power supply systems requiring ultra-low standby power consumption, meeting Level 6 energy efficiency and the European energy standard Eur2.0 applications.

Features

● Built-in High-Voltage MOSFET Power Switch

● High-Efficiency Quasi-Resonant Mode Operation

● Multi-Mode Primary-Side Control

● Primary-Side Feedback Control Eliminates Optocoupler and TL431

● Optimized Dynamic Response

● Standby Power Consumption <75mW

● ±5% Constant Current and Constant Voltage Accuracy

● Adjustable Line Loss Compensation

● Built-in Line Voltage and Primary Inductance Compensation

● Built-in Adaptive Peak Current Adjustment

● Output Short-Circuit Protection

● Operation with No Audio Noise

● Power-On Soft Start

● Built-in Leading Edge Blanking (LEB) Function

● Cycle-by-Cycle Current Limiting (OCP)

● Output Diode Short-Circuit Protection

● Under-Voltage Lockout (UVLO), Over-Voltage Protection (OVP), VDD Voltage Clamp Protection

Applications

● Chargers

● Power Adapters for PDAs, Digital Cameras, Camcorders

● Set-Top Box Power Supplies

● Open-Frame Switching Power Supplies

● PC Auxiliary Power Supplies