The CS51021A/2A/3A/4A Fixed Frequency PWM Current Mode Controller family provides all necessary features required for AC−DC or DC−DC primary side control. Several features are included eliminating the additional components needed to implement them externally. In addition to low startup current (75 A) and high frequency operation capability, the CS51021A/2A/3A/4A family includes overvoltage and undervoltage monitoring, externally programmable dual threshold overcurrent protection, current sense leading edge blanking, current slope compensation, accurate duty cycle control and an externally available 5.0 V reference.

FEATUREs
• 75 A Max. Startup Current
• Fixed Frequency Current Mode Control
• 1.0 MHz Switching Frequency
• Undervoltage Protection Monitor
• Overvoltage Protection Monitor with Programmable Hysteresis
• Programmable Dual Threshold Overcurrent Protection with Delayed Restart
• Programmable Soft Start
• Accurate Maximum Duty Cycle Limit
• Programmable Slope Compensation
• Leading Edge Current Sense Blanking
• 1.0 A Sink/Source Gate Drive
• Bidirectional Synchronization (CS51021A/3A)
• 50 ns PWM Propagation Delay
• 100 A Max Sleep Current (CS51022A/4A)
• Pb−Free Packages are Available*