SLUSD60 October   2017 UCC256304

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 Switching Characteristics
    7. 6.7 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  Hybrid Hysteretic Control
      2. 7.3.2  Regulated 12-V Supply
      3. 7.3.3  Feedback Chain
      4. 7.3.4  Optocoupler Feedback Signal Input and Bias
      5. 7.3.5  System External Shut Down
      6. 7.3.6  Pick Lower Block and Soft Start Multiplexer
      7. 7.3.7  Pick Higher Block and Burst Mode Multiplexer
      8. 7.3.8  VCR Comparators
      9. 7.3.9  Resonant Capacitor Voltage Sensing
      10. 7.3.10 Resonant Current Sensing
      11. 7.3.11 Bulk Voltage Sensing
      12. 7.3.12 Output Voltage Sensing
      13. 7.3.13 High Voltage Gate Driver
      14. 7.3.14 Protections
        1. 7.3.14.1 ZCS Region Prevention
        2. 7.3.14.2 Over Current Protection (OCP)
        3. 7.3.14.3 Over Output Voltage Protection (VOUTOVP)
        4. 7.3.14.4 Over Input Voltage Protection (VINOVP)
        5. 7.3.14.5 Under Input Voltage Protection (VINUVP)
        6. 7.3.14.6 Boot UVLO
        7. 7.3.14.7 RVCC UVLO
        8. 7.3.14.8 Over Temperature Protection (OTP)
    4. 7.4 Device Functional Modes
      1. 7.4.1 Burst Mode Control
      2. 7.4.2 High Voltage Start-Up
      3. 7.4.3 X-Capacitor Discharge
      4. 7.4.4 Soft-Start and Burst-Mode Threshold
      5. 7.4.5 System States and Faults State Machine
      6. 7.4.6 Waveform Generator State Machine
  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  LLC Power Stage Requirements
        3. 8.2.2.3  LLC Gain Range
        4. 8.2.2.4  Select Ln and Qe
        5. 8.2.2.5  Determine Equivalent Load Resistance
        6. 8.2.2.6  Determine Component Parameters for LLC Resonant Circuit
        7. 8.2.2.7  LLC Primary-Side Currents
        8. 8.2.2.8  LLC Secondary-Side Currents
        9. 8.2.2.9  LLC Transformer
        10. 8.2.2.10 LLC Resonant Inductor
        11. 8.2.2.11 LLC Resonant Capacitor
        12. 8.2.2.12 LLC Primary-Side MOSFETs
        13. 8.2.2.13 Design Considerations for Adaptive Dead-Time
        14. 8.2.2.14 LLC Rectifier Diodes
        15. 8.2.2.15 LLC Output Capacitors
        16. 8.2.2.16 HV Pin Series Resistors
        17. 8.2.2.17 BLK Pin Voltage Divider
        18. 8.2.2.18 BW Pin Voltage Divider
        19. 8.2.2.19 ISNS Pin Differentiator
        20. 8.2.2.20 VCR Pin Capacitor Divider
        21. 8.2.2.21 Burst Mode Programming
        22. 8.2.2.22 Soft-Start Capacitor
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
    1. 9.1 VCC Pin Capacitor
    2. 9.2 Boot Capacitor
    3. 9.3 RVCC Pin Capacitor
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Development Support
        1. 11.1.1.1 Custom Design With WEBENCH® Tools
    2. 11.2 Documentation Support (if applicable)
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Community Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

1 Features

  • Hybrid Hysteretic Control (HHC)
    • Best-in-Class Transient Response
    • Easy Compensation Design
  • Optimized Low Power Features Enable 75 mW
    Standby Power Design with PFC on
    • Advanced Burst Mode
      Opto-Coupler Low Power Operation
    • Helps Enable Compliance to CoC Tier II Standard
  • Fast Exit from Burst Mode
  • Improved Capacitive Region Avoidance Scheme
  • Adaptive Dead-Time
  • Internal High-Side Gate Drivers
    (0.6-A and 1.2-A Capability)
  • Robust Soft Start with No Hard Switching
  • Over Temperature, Output Over Voltage, Input
    Over and Under Voltage Protection with
    Three Levels of Over Current Protections
  • Wide Operating Frequency Range
    (35 kHz to 1 MHz)
  • Nemko Certification for X Cap Discharge Function
  • Wide DC Input Range
  • Enables Wide AC Input Range
  • PFC Startup Not Required For LLC Startup
  • Create a Custom Design Using the UCC256304 With the WEBENCH® Power Designer

2 Applications

  • Digital TV SMPS
  • AC-DC Adapter
  • Multi-Functional Printers
  • Projectors
  • Merchant DC-to-DC
  • High Power Battery Charging
  • DIN Rail Power Supply
  • Multi-Axis Servo
  • ATX Power Supply
  • Appliances
  • LED Lighting Applications

3 Description

The UCC256304 is a fully featured LLC controller with integrated high-voltage gate driver. It has been designed to pair with a PFC stage to provide a complete power system using a minimum of external components. The resulting power system is designed to meet the most stringent requirements for standby power without the need for a separate standby power converter.UCC256304 uses hybrid hysteretic control to provide best in class line and load transient response. The control makes the open loop transfer function a first order system so that it’s very easy to compensate and is always stable with proper frequency compensation.

The UCC256304 is unique in that the controller is able to operate over a large DC input range. This is accomplished by making the input overvoltage sense threshold much larger than the input voltage start threshold. This allows the LLC to startup and enter a low power standby mode without the need to enable the PFC and enables the LLC to accommodate an extensive range of common AC inputs.

UCC256304 provides a highly efficient burst mode with consistent burst power level during each burst on cycle. The burst power level is programmable and adaptively changes with input voltage.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
UCC256304 SOIC (14) 9.9 mm x 3.9 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Simplified Schematic

UCC256304 UCC256304 Simplified Diagram.gif

4 Revision History

DATE REVISION NOTES
October 2017 * Initial release.