SNVS703H February   2011  – November 2014 LM5046

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 Handling 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 & SR2)
      14. 7.3.14 Soft-Start of the Synchronous Rectifiers
      15. 7.3.15 Pre-Bias 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  Phase-Shifted Full-Bridge Operation
          1. 8.2.2.1.1 Operating State 1 (Power Transfer/Active Mode)
          2. 8.2.2.1.2 Operating State 2 (Active to Passive Transition)
          3. 8.2.2.1.3 Operating State 3 (Freewheel/Passive Mode)
          4. 8.2.2.1.4 Operating State 4 (Passive to Active Transition)
        2. 8.2.2.2  Control Method Selection
        3. 8.2.2.3  Voltage Mode Control Using the LM5046
        4. 8.2.2.4  Current Mode Control Using the LM5046
        5. 8.2.2.5  VIN and VCC
        6. 8.2.2.6  For Applications With > 100 V Input
        7. 8.2.2.7  UVLO and OVP Voltage Divider Selection
        8. 8.2.2.8  Current Sense
        9. 8.2.2.9  Hiccup Mode Current Limit Restart
        10. 8.2.2.10 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 Turn-on into Prebiased Loads
  • Synchronous Rectifiers Disabled in UVLO Mode and Hiccup Mode
  • Two Independent, Programmable Dead-Time Adjustments to Enable Zero-Volt Switching
  • Four High-Current 2-A Bridge Gate Drivers
  • Wide-Bandwidth Opto-Coupler 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/Electronic Warfare
  • Power: Telecom DC/DC Module: Analog
  • Private Branch Exchange (PBX)
  • Solar Power Inverters
  • Vector Signal Generator
  • Microwave Oven
  • Point-to-Point Microwave Backhaul
  • Power: Telecom/Server AC/DC Supply: Dual Controller: Analog
  • Solar Micro-Inverter
  • TETRA Base Station
  • Washing Machine: Low-End

3 Description

The LM5046 PWM controller contains all of the features necessary to implement a phase-shifted full-bridge topology power converter 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- 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 dead-time to enable zero-volt switching of the primary FETs. Intelligent startup 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)
LM5046 HTSSOP (28) 9.70 mm x 4.40 mm
WSON (28) 5.00 mm x 5.00 mm
  1. For all available packages, see the orderable addendum at the end of the datasheet.

Simplified Phase-Shifted Full-Bridge Power Converter

Simp Phase Shifted FB Pwr Conv.gif