SLUSER8C June   2022  – March 2023 UCC28C50 , UCC28C51 , UCC28C52 , UCC28C53 , UCC28C54 , UCC28C55 , UCC28C56H , UCC28C56L , UCC28C57H , UCC28C57L , UCC28C58 , UCC28C59 , UCC38C50 , UCC38C51 , UCC38C52 , UCC38C53 , UCC38C54 , UCC38C55

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  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  Detailed Pin Description
        1. 8.3.1.1 COMP
        2. 8.3.1.2 FB
        3. 8.3.1.3 CS
        4. 8.3.1.4 RT/CT
        5. 8.3.1.5 GND
        6. 8.3.1.6 OUT
        7. 8.3.1.7 VDD
        8. 8.3.1.8 VREF
      2. 8.3.2  Undervoltage Lockout
      3. 8.3.3  ±1% Internal Reference Voltage
      4. 8.3.4  Current Sense and Overcurrent Limit
      5. 8.3.5  Reduced-Discharge Current Variation
      6. 8.3.6  Oscillator Synchronization
      7. 8.3.7  Soft-Start Timing
      8. 8.3.8  Enable and Disable
      9. 8.3.9  Slope Compensation
      10. 8.3.10 Voltage Mode
    4. 8.4 Device Functional Modes
      1. 8.4.1 Normal Operation
      2. 8.4.2 UVLO Mode
  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  Input Bulk Capacitor and Minimum Bulk Voltage
        2. 9.2.2.2  Transformer Turns Ratio and Maximum Duty Cycle
        3. 9.2.2.3  Transformer Inductance and Peak Currents
        4. 9.2.2.4  Output Capacitor
        5. 9.2.2.5  Current Sensing Network
        6. 9.2.2.6  Gate Drive Resistor
        7. 9.2.2.7  VREF Capacitor
        8. 9.2.2.8  RT/CT
        9. 9.2.2.9  Start-Up Circuit
        10. 9.2.2.10 Voltage Feedback Compensation
          1. 9.2.2.10.1 Power Stage Poles and Zeroes
          2. 9.2.2.10.2 Slope Compensation
          3. 9.2.2.10.3 Open-Loop Gain
          4. 9.2.2.10.4 Compensation Loop
      3. 9.2.3 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
        1. 9.4.1.1 Precautions
        2. 9.4.1.2 Feedback Traces
        3. 9.4.1.3 Bypass Capacitors
        4. 9.4.1.4 Compensation Components
        5. 9.4.1.5 Traces and Ground Planes
      2. 9.4.2 Layout Example
  10. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Third-Party Products Disclaimer
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
    3. 10.3 Receiving Notification of Documentation Updates
    4. 10.4 Support Resources
    5. 10.5 Trademarks
    6. 10.6 Electrostatic Discharge Caution
    7. 10.7 Glossary
  11. 11Mechanical, Packaging, and Orderable Information

Package Options

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

7.6 Typical Characteristics

GUID-AFB31408-E964-4116-8840-2B8AB24DFA9B-low.gifFigure 7-1 Oscillator Frequency vs Timing Resistance and Capacitance
GUID-A2CE145F-A109-482F-9B90-81146F3EBFC6-low.gifFigure 7-3 Error Amplifier Frequency Response
GUID-20221028-SS0I-5VGZ-MTKN-DT82STCTHGZC-low.svg
Group 1: UCCx8C50 to UCCx8C55Group 2: UCC28C56H/L, UCC28C57H/L, and UCC28C58/9
Figure 7-5 Reference Voltage vs Temperature
GUID-20220513-SS0I-ZK9S-VLPW-VPVWM4BCFXZQ-low.svg

Group 1: UCCx8C50 to UCCx8C55Group 2: UCC28C56H/L, UCC28C57H/L, and UCC28C58/9

Figure 7-7 Reference Short-Circuit Current vs Temperature
GUID-4B6E3F22-D4F9-4015-A3FA-1C4321E47796-low.gif
UCCx8C52 and UCCx8C54
Figure 7-9 Undervoltage Lockout vs Temperature
GUID-4314F1CB-FDC7-4C58-AC0F-EB95ABEF45CE-low.gif
UCCx8C50 and UCCx8C51
Figure 7-11 Undervoltage Lockout vs Temperature
GUID-20220401-SS0I-ZWVH-2FQR-HBQJ5QTQSK2X-low.svg
UCC28C56L and UCC28C57L
Figure 7-13 Undervoltage Lockout vs Temperature
GUID-20221101-SS0I-WKFT-RVPZ-DCV6PNCZX4VC-low.svgFigure 7-15 Supply Current vs Oscillator Frequency
GUID-9DE6F354-07A5-434A-9D30-61A6ACAD8EF8-low.gifFigure 7-17 Output Rise Time and Fall Time vs Temperature
GUID-C6FF4B06-3FA6-427C-873F-43C057A572DB-low.gifFigure 7-19 Maximum Duty Cycle vs Temperature
GUID-20220513-SS0I-2DVP-ZJV7-1NXSQ0TDRHXZ-low.svg
Group 1: UCCx8C50 to UCCx8C55Group 2: UCC28C56H/L, UCC28C57H/L, and UCC28C58/9
Figure 7-21 Current Sense Threshold Voltage vs Temperature
GUID-20221028-SS0I-MHMC-RGHN-BVST27PH9VSP-low.svg
Group 1: UCCx8C50 to UCCx8C55Group 2: UCC28C56H/L, UCC28C57H/L, and UCC28C58/9
Figure 7-2 Oscillator Discharge Current vs Temperature
GUID-20220513-SS0I-XNDM-1TF5-6HZ0BTWN2N9R-low.svg

VCS = 0 V
Group 1: UCCx8C50 to UCCx8C55Group 2: UCC28C56H/L, UCC28C57H/L, and UCC28C58/9

Figure 7-4 COMP to CS Offset Voltage vs Temperature
GUID-20221028-SS0I-J6FC-QF7T-L8SXQM0JHWWV-low.svg
Group 1: UCCx8C50 to UCCx8C55Group 2: UCC28C56H/L, UCC28C57H/L, and UCC28C58/9
Figure 7-6 Error Amplifier Reference Voltage vs Temperature
GUID-6E1AE9A9-3E2F-4B73-89B4-E7010867675C-low.gifFigure 7-8 Error Amplifier Input Bias Current vs Temperature
GUID-5B652379-CBA4-47B1-93FD-E7484A35BF9A-low.gif
UCCx8C53 and UCCx8C55
Figure 7-10 Undervoltage Lockout vs Temperature
GUID-20220401-SS0I-S64C-KKCQ-PBX18PHV7F3W-low.svg
UCC28C56H and UCC28C57H
Figure 7-12 Undervoltage Lockout vs Temperature
GUID-20220401-SS0I-P6DM-63QN-TR9BTQV3JDRK-low.svg
UCC28C58 and UCC28C59
Figure 7-14 Undervoltage Lockout vs Temperature
GUID-9B997949-B19E-4D4E-8DB4-AA81F05E8A56-low.svg
Group 1: UCCx8C50 to UCCx8C55Group 2: UCC28C56H/L, UCC28C57H/L, and UCC28C58/9
Figure 7-16 Supply Current vs Temperature
GUID-06B9D1A7-2754-453F-B726-CA2E582CA081-low.gifFigure 7-18 Maximum Duty Cycle vs Oscillator Frequency
GUID-3B9401BD-2480-477D-B19C-D1EA0F5A2447-low.gifFigure 7-20 Maximum Duty Cycle vs Temperature
GUID-F5468E97-3074-49FF-AB75-99232AE57617-low.gifFigure 7-22 Current Sense to Output Delay Time vs Temperature