SLUSAD7B April   2011  – July 2016 UCC25710

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Multi-transformer Architecture
      2. 8.3.2 Start-Up and Non-Dimming Operation
      3. 8.3.3 Dimming Operation
      4. 8.3.4 Fault Condition Operation
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1  Determining Transformer and Resonant Circuit Parameters
        2. 9.2.2.2  CS (Output Current Sense)
        3. 9.2.2.3  ICOMP (Current Amplifier Compensation)
        4. 9.2.2.4  SS (Soft Start)
        5. 9.2.2.5  FMAX (Maximum VCO Frequency)
        6. 9.2.2.6  FMIN (Minimum VCO Frequency)
        7. 9.2.2.7  GD1 and GD2 (Gate Drive 1 and 2)
        8. 9.2.2.8  LEDSW (LED Switch Drive)
        9. 9.2.2.9  DSR (Dimming Slew Rate)
        10. 9.2.2.10 DTY (Dimming Duty-Cycle Average)
        11. 9.2.2.11 DADJ (Dimming Duty-Cycle Adjust)
        12. 9.2.2.12 OV (Output Overvoltage)
        13. 9.2.2.13 UV (Output Undervoltage)
        14. 9.2.2.14 CL (Current Limit)
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Receiving Notification of Documentation Updates
    2. 12.2 Community Resource
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

1 Features

  • Closed-Loop LED String Current Control
  • PWM Dimming Input
  • Adjustable FMIN (3% accuracy), and FMAX (7.5% Accuracy)
  • LLC and Series LED Switch Control for Dimming
  • Programmable Dimming LLC ON/OFF Ramp for Elimination of Audible Noise
  • Closed-Loop Current Control at Low Dimming Duty Cycles
  • Programmable Soft Start
  • Accurate VREF for Tight Output Regulation
  • Overvoltage, Undervoltage and Input Overcurrent Protection With Auto-Restart Response
  • Second Overcurrent Threshold With Latch-Off Response
  • 400-mA/-800-mA Gate Drive Current
  • Low Start-Up and Operating Currents
  • Lead (Pb)-Free, 20-Pin, SOIC Package

2 Applications

  • LED Backlight for LCD TV and Monitors
  • LED General Lighting

    • SPACE

3 Description

The UCC25710 device is an LLC half-bridge controller for accurate control of multi-string LED backlight applications. It is optimized for multi-transformer, multi-string LED architectures. Superior LED current matching in multiple strings can be achieved with this controller and architecture. Compared to existing LED backlight solutions, the multi-transformer architecture provides the highest overall efficiency from AC input to LED load.

The LLC controller function includes a Voltage Controlled Oscillator (VCO) with programmable FMIN and FMAX, half-bridge gate drivers with a fixed dead time of 500 ns and a GM current amplifier. The LLC power delivery is modulated by the controller’s VCO frequency. The VCO has an accurate and programmable frequency range. At very low power levels the VCO frequency goes from FMAX to zero to maximize efficiency at low LED currents.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
UCC25710 SOIC (20) 12.80 mm × 7.50 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Simplified Application Diagram

UCC25710 fp_schematic.gif

Efficiency and Linearity Results (Dual 45-W Strings)

UCC25710 fp_graph.gif