CS51021A, CS51022A, CS51023A, CS51024A
Enhanced Current Mode PWM Controller
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. The CS51021A
and CS51023A feature bidirectional synchronization capability, while
the CS51022A and CS51024A offer a sleep mode with 100 A
maximum IC current consumption. The CS51021A/2A/3A/4A family
is available in a 16 lead narrow body SOIC package.

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*