LM5021 AC-DC Current Mode PWM Controller | TI.com

LM5021 (ACTIVE)

AC-DC Current Mode PWM Controller

AC-DC Current Mode PWM Controller - LM5021
 

Special note

Maximum Duty Cycle Limiting (80% for LM5021-1 or 50% for LM5021-2)

Description

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.

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 0.7 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

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Parametrics Compare all products in Flyback controllers

 
Control Method
Duty Cycle (Max) (%)
Frequency (Max) (kHz)
UVLO Thresholds On/Off (V)
Features
Operating Temperature Range (C)
Package Group
Rating
Package Size: mm2:W x L (PKG)
LM5021 LM5021-Q1
Current     Current    
80     80    
1000     1000    
20/7.25     20/7.25    
SSR
DCM
CCM
Frequency Synchronization    
SSR
DCM
CCM
Frequency Synchronization    
-40 to 125     -40 to 125    
PDIP | 8
VSSOP | 8    
VSSOP | 8    
Catalog     Automotive    
See datasheet (PDIP)
8VSSOP: 15 mm2: 4.9 x 3 (VSSOP | 8)    
8VSSOP: 15 mm2: 4.9 x 3 (VSSOP | 8)    

WEBENCH® Designer LM5021

 AC  DC  
AC Frequency  60 Hz  50 Hz
  Min   Max Range
Vin  V 85.0 to 500.0V
Product Option
Vout  V 3.3 to 48.0V
Iout  A ≤ 5.0A
Ambient Temp  °C -40.0 to 125.0°C