SNVS961E APRIL   2013  – January 2016 LM5023

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Detailed Pin Description
        1. 7.3.1.1 QR Pin
        2. 7.3.1.2 VSD Pin
        3. 7.3.1.3 SS Pin
        4. 7.3.1.4 COMP Pin
        5. 7.3.1.5 CS Pin
        6. 7.3.1.6 GND Pin
        7. 7.3.1.7 OUT Pin
        8. 7.3.1.8 VCC Pin
      2. 7.3.2 Start-Up
      3. 7.3.3 Quasi-Resonant Operation
      4. 7.3.4 Quasi-Resonant Operating Frequency
      5. 7.3.5 PWM Comparator
      6. 7.3.6 Soft-Start
      7. 7.3.7 Gate Driver
        1. 7.3.7.1 Skip-Cycle Operation
      8. 7.3.8 Current Limit and Current Sense
    4. 7.4 Device Functional Modes
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Custom Design with WEBENCH Tools
        2. 8.2.2.2 Line Current-Limit Feedforward
          1. 8.2.2.2.1 Overvoltage Protection
        3. 8.2.2.3 Valley Switching
        4. 8.2.2.4 Hiccup Mode
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Custom Design with WEBENCH Tools
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

1 Features

  • Critical Conduction Mode
  • Peak-Current Mode Control
  • Skip-Cycle Mode for Low-Standby Power
  • Hiccup Mode for Continuous Overload Protection
  • Cycle-by-Cycle Overcurrent Protection Maintains Accuracy Over the Universal AC Line
  • Line-Voltage Feedforward
  • OVP Protection by Sensing the Auxiliary Winding
  • Integrated 0.7-A Peak Gate Driver
  • Direct Opto-Coupler Interface
  • Leading Edge Blanking of Current Sense Signal
  • Maximum Frequency Clamp 130 kHz
  • Programmable Soft-Start
  • Thermal Shutdown
  • 8-Pin VSSOP Package
  • Create a Custom Design using the LM5023 with the WEBENCH Power Designer

2 Applications

  • Universal Input AC-to-DC Notebook Adapters from 10 W to 65 W
  • High-Efficiency Housekeeping and Auxiliary Power Supplies
  • Battery Chargers
  • Consumer Electronics (DVD Players, Set-Top Boxes, DTV, Gaming, Printers)

3 Description

The LM5023 is a quasi-resonant pulse width modulated (PWM) controller which contains all of the features needed to implement a highly efficient off-line power supply. The LM5023 uses the transformer auxiliary winding for demagnetization detection to ensure critical conduction mode (CrCM) operation. The LM5023 features a hiccup mode for overcurrent protection with an auto restart to reduce the stress on the power components during an overload. A skip-cycle mode reduces power consumption at light loads for energy conservation applications (ENERGY STAR®, CEPCP, and so forth). The LM5023 also uses the transformer auxiliary winding for output overvoltage protection (OVP); if an OVP fault is detected the LM5023 latches off the controller.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
LM5023 VSSOP (8) 3.00 mm × 3.00 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Simplified Schematic

LM5023 alt_nvs961.gif