Texas Instruments LM5021

Description

The LM5021 off-line pulse width modulation (PWM) controller contains all of the features needed to implement highly efficient off-line single-endedflyback and forward power converters using currentmode 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, etc.). Additional features includeunder-voltage lockout, cycle-by-cycle current limit, hiccup mode overload protection, slope com- pensation, soft-start and oscillator synchronizationcapability. This high performance 8-pin IC has total propagation delays less than 100nS and a 1MHz capable oscillator that is programmed with a singleresistor.

Features

• 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 0.7A Peak Gate Driver
• Direct Opto-Coupler Interface
• Maximum Duty Cycle Limiting (80% for LM5021-1 or 50% for LM5021-2)
• Slope Compensation for (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

Typical applications

• SMPS for Smart Meters
• Isolated Telecom Power SuppliesIsolated Telecom Power Supplies
• Industrial Power Conversion
• Audio Amplifiers
• Building Automation and White Goods SMPS

More information

• Datasheet
• IC product information