The LM5021 off-line pulse width modulation (PWM) controller contains all of the features needed to implement highly efficient off-line single-ended flyback and forward power converters using current-mode control. The LM5021 features include an ultra-low (25 µA) start-up current, which minimizes power losses in the high voltage start-up network. A skip cycle mode reduces power consumption with light loads for energy conserving applications (ENERGY STAR®, CECP, and so forth). Additional features include under-voltage lockout, cycle-by-cycle current limit, hiccup mode overload protection, slope compensation, soft-start and oscillator synchronization capability. This high performance 8-pin IC has total propagation delays less than 100 ns and a 1-MHz capable oscillator that is programmed with a single resistor.
● Ultra Low Start-up Current (25 µA maximum)
● Current Mode Control
● Skip Cycle Mode for Low Standby Power
● Single Resistor Programmable Oscillator
● Synchronizable Oscillator
● Adjustable Soft-Start
● Integrated 0.7 A Peak Gate Driver
● Direct Opto-Coupler Interface
● Maximum Duty Cycle Limiting (80% for LM5021-1
●or 50% for LM5021-2)
● Slope Compensation (LM5021-1 Only)
● Under Voltage Lockout (UVLO) with Hysteresis
● Cycle-by-Cycle Over-Current Protection
● Hiccup Mode for Continuous Overload Protection
● Leading Edge Blanking of Current Sense Signal
● Packages: VSSOP-8 or PDIP-8
