The CS51221 Enhanced Voltage Mode PWM Controller contains all of the features necessary for basic voltage mode operation. This PWM controller has been optimized for high frequency primary side control operation. In addition, this device includes such features as: Soft Start, accurate duty cycle limit control, less than 50uA startup current, over and under voltage protection and bidirectional synchronization. The CS51221 is available in a SOIC-16 and TSSOP-16 surface mount packages.

• 1MHz Frequency Capability
• Fixed Frequency Voltage Mode Operation, with Feed Forward
• Thermal Shutdown
• Under Voltage Lock-out
• Accurate Programmable Max Duty Cycle Limit
• 1A Sink/Source Gate Drive
• Programmable Pulse-by-Pulse Overcurrent Protection
• Leading Edge Current Sense Blanking
• 75ns Shutdown Propagation Delay
• Programmable Soft Start
• Undervoltage Protection
• Overvoltage Protection with Programmable Hysteresis
• Bi-directional Synchronization
• 25ns GATE Rise and Fall Time (1nF load)
• 3.3V 3% Reference Voltage Output
• Pb-Free Package is Available