SNVS699H February   2011  – January 2015 LM5045

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  High-Voltage Start-Up Regulator
      2. 7.3.2  Line Undervoltage Detector
      3. 7.3.3  Overvoltage Protection
      4. 7.3.4  Reference
      5. 7.3.5  Oscillator, Sync Input
      6. 7.3.6  Cycle-by-Cycle Current Limit
      7. 7.3.7  Hiccup Mode
      8. 7.3.8  PWM Comparator
      9. 7.3.9  Ramp Pin
      10. 7.3.10 Slope Pin
      11. 7.3.11 Soft-Start
      12. 7.3.12 Gate Driver Outputs
      13. 7.3.13 Synchronous Rectifier Control Outputs (SR1 and SR2)
      14. 7.3.14 Soft-Start of the Synchronous Rectifiers
      15. 7.3.15 Prebias Startup
      16. 7.3.16 Soft-Stop
      17. 7.3.17 Soft-Stop Off
      18. 7.3.18 Thermal Protection
    4. 7.4 Device Functional Modes
      1. 7.4.1 Control Method Selection
      2. 7.4.2 Voltage Mode Control Using the LM5045
      3. 7.4.3 Current Mode Control Using the LM5045
  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 VIN and VCC
        2. 8.2.2.2 For Applications With > 100 VIN
        3. 8.2.2.3 UVLO and OVP Voltage Divider Selection
        4. 8.2.2.4 Current Sense
        5. 8.2.2.5 Hiccup Mode Current Limit Restart
        6. 8.2.2.6 Augmenting the Gate Drive Strength
      3. 8.2.3 Application Curve
  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 Trademarks
    2. 11.2 Electrostatic Discharge Caution
    3. 11.3 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

1 Features

  • Highest Integration Controller for Small Form Factor, High-Density Power Converters
  • High-Voltage Start-Up Regulator
  • Intelligent Sync Rectifier Start-Up Allows Linear Turnon Into Prebiased Loads
  • Synchronous Rectifiers Disabled in UVLO mode and Hiccup Mode
  • Two Independent, Programmable Synchronous Rectifier Dead-Time Adjustments
  • Four High-Current 2-A Bridge Gate Drivers
  • Wide-Bandwidth Optocoupler Interface
  • Configurable for Either Current Mode or Voltage Mode Control
  • Dual-Mode Overcurrent Protection
  • Resistor Programmed 2-MHz Oscillator
  • Programmable Line UVLO and OVP

2 Applications

  • E-Bike
  • Military: Radar and Electronic Warfare
  • Power: Telecom DC-DC Module: Analog
  • Private Branch Exchange (PBX)
  • Solar Power Inverters
  • Vector Signal Generators
  • Microwave Ovens
  • Point-to-Point Microwave Backhaul
  • Power: Telecom/Server AC/DC Supply: Dual Controller: Analog
  • Solar Micro-Inverters
  • TETRA Base Stations
  • Washing Machine: Low-End

3 Description

The LM5045 PWM controller contains all of the features necessary to implement full-bridge topology power converters using either current mode or voltage mode control. This device is intended to operate on the primary side of an isolated DC-DC converter with input voltage up to 100 V. This highly integrated controller-driver provides dual 2-A high-side and low-side gate drivers for the four external bridge MOSFETs plus control signals for the secondary-side synchronous rectifier MOSFETs. External resistors program the leading and trailing edge dead-time between the main and synchronous rectifier control signals. Intelligent start-up of the synchronous rectifiers allows monotonic turnon of the power converter even with prebias load conditions. Additional features include cycle-by-cycle current limiting, hiccup mode restart, programmable soft-start, synchronous rectifier soft-start, and a 2-MHz capable oscillator with synchronization capability and thermal shutdown.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
LM5045 HTSSOP (28) 9.70 mm × 4.40 mm
WQFN (28) 5.00 mm × 5.00 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Simplified Full-Bridge Power Converter

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