SLUSBW3D March   2014  – December 2017 UCC28630 , UCC28631 , UCC28632 , UCC28633 , UCC28634

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
    1.     Device Images
      1.      Simplified Schematic
      2.      Typical Application Measured Regulation
  4. Revision History
  5. Device Comparison Table
  6. Pin Configuration and Functions
    1.     PIN Functions
  7. Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information (UCC28630, UCC28631)
    5. 7.5 Thermal Information (UCC28632, UCC28633, (UCC28630, UCC28634)
    6. 7.6 Electrical Characteristics
    7. 7.7 Typical Characteristics
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  High-Voltage Current Source Start-Up Operation
      2. 8.3.2  AC Input UVLO / Brownout Protection
      3. 8.3.3  Active X-Capacitor Discharge (UCC28630 and UCC28633 only)
        1. 8.3.3.1 Improved Performance with UCC28630 and UCC28633
      4. 8.3.4  Magnetic Input and Output Voltage Sensing
      5. 8.3.5  Fixed-Point Magnetic Sense Sampling Error Sources
      6. 8.3.6  Magnetic Sense Resistor Network Calculations
        1. 8.3.6.1 Step 1
        2. 8.3.6.2 Step 2
        3. 8.3.6.3 Step 3
        4. 8.3.6.4 Step 4
      7. 8.3.7  Magnetic Sensing: Power Stage Design Constraints
      8. 8.3.8  Magnetic Sense Voltage Control Loop
      9. 8.3.9  Peak Current Mode Control
      10. 8.3.10 IPEAK Adjust vs. Line
      11. 8.3.11 Primary-Side Constant-Current Limit (CC Mode)
      12. 8.3.12 Primary-Side Overload Timer (UCC28630 only)
      13. 8.3.13 Overload Timer Adjustment (UCC28630 only)
      14. 8.3.14 CC-Mode IOUT(lim) Adjustment
      15. 8.3.15 Fault Protections
      16. 8.3.16 Pin-Fault Detection and Protection
      17. 8.3.17 Over-Temperature Protection
      18. 8.3.18 External Fault Input
      19. 8.3.19 External SD Pin Wake Input (except UCC28633)
      20. 8.3.20 External Wake Input at VSENSE Pin (UCC28633 Only)
      21. 8.3.21 Mode Control and Switching Frequency Modulation
      22. 8.3.22 Frequency Dither For EMI (except UCC28632)
    4. 8.4 Device Functional Modes
      1. 8.4.1 Device Internal Key Parameters
  9. Applications and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Notebook Adapter, 19.5 V, 65 W
      2. 9.2.2 UCC28630 Application Schematic
      3. 9.2.3 Design Requirements
      4. 9.2.4 Detailed Design Procedure
        1. 9.2.4.1  Custom Design With WEBENCH® Tools
        2. 9.2.4.2  Input Bulk Capacitance and Minimum Bulk Voltage
        3. 9.2.4.3  Transformer Turn Ratio
        4. 9.2.4.4  Transformer Magnetizing Inductance
        5. 9.2.4.5  Current Sense Resistor RCS
        6. 9.2.4.6  Transformer Constraint Verification
        7. 9.2.4.7  Transformer Selection and Design
        8. 9.2.4.8  Slope Compensation Verification
        9. 9.2.4.9  Power MOSFET and Output Rectifier Selection
        10. 9.2.4.10 Output Capacitor Selection
        11. 9.2.4.11 Calculation of CC Mode Limit Point
        12. 9.2.4.12 VDD Capacitor Selection
        13. 9.2.4.13 Magnetic Sense Resistor Network Selection
        14. 9.2.4.14 Output LED Pre-Load Resistor Calculation
      5. 9.2.5 External Wake Pulse Calculation at VSENSE Pin (UCC28633 Only)
      6. 9.2.6 Energy Star Average Efficiency and Standby Power
      7. 9.2.7 Application Performance Plots
    3. 9.3 Dos and Don'ts
      1. 9.3.1 Test and Debug Recommendations
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 HV Pin
      2. 11.1.2 VDD Pin
      3. 11.1.3 VSENSE Pin
      4. 11.1.4 CS Pin
      5. 11.1.5 SD Pin
      6. 11.1.6 DRV Pin
      7. 11.1.7 GND Pin
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Development Support
        1. 12.1.1.1 Custom Design With WEBENCH® Tools
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
        1. 12.2.1.1 Related Links
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Community Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

VSENSE Pin

  • The tracking and layout of the VSENSE pin and connecting components is critical to minimizing noise pick-up and interference in the magnetic sensing block. (See Figure 63 for suggested component placement and tracking). Reduce the total surface area of traces on the VSENSE net to a minimum.
  • Because the resistance values of RA and RB are relatively high to minimize power dissipation, the high impedance makes the VSENSE pin potentially noise-sensitive. To minimize noise pick-up, locate resistors RA and RB as close as possible to the VSENSE pin, with RB in particular placed as directly as possible between VSENSE and GND pins;
  • Depending on layout, a small noise filter capacitor may be useful on the VSENSE pin, such as C15 shown in Figure 44. Connect this capacitor as directly as possible between the VSENSE and GND pins. Choose the value of this capacitor as small as possible, and no greater than 10 pF. A larger value significantly delays the voltage rise-time at the pin, and affects the regulation set-point;
  • In case of possible board faults that can pull the VSENSE pin below GND (such as R7 shorted), in order to protect the pin and limit possible negative current out of the pin, a series resistor R4 (as shown in Figure 44) and clamping diode from GND are recommended. Maintain the value of R4 between 100 Ω and 500 Ω. A larger value may affect regulation and line sense accuracy.
  • For correct line sense operation, the switched pull-up R10 and D4 must be added. The value of R10 must be 3.9 kΩ to match the internal device gain. The switched pull-up diode and the GND clamping diode can be combined into a dual-diode common-cathode package, such as D4 as shown in Figure 44.