SLUSEW0 December   2023 UCC28750

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison
  6. 5 Pin Configuration and Functions
  7. 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 Timing Requirements
    8. 6.8 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Detailed Pin Descriptions
      1. 7.3.1 VDD - Input Bias
      2. 7.3.2 DRV - Gate Drive Out
      3. 7.3.3 CS - Current Sensing
      4. 7.3.4 FB - Feedback
      5. 7.3.5 FLT - Fault
      6. 7.3.6 GND - Ground Return
    4. 7.4 Feature Description
      1. 7.4.1 Soft Start
      2. 7.4.2 Control Law
      3. 7.4.3 Frequency Dithering
      4. 7.4.4 Fault Protections
        1. 7.4.4.1 VDD Overvoltage and Undervoltage Lockout
        2. 7.4.4.2 Internal Overtemperature Protection
        3. 7.4.4.3 Output Overpower Protection
        4. 7.4.4.4 Output Short-Circuit Protection
        5. 7.4.4.5 FLT Pin Protections
      5. 7.4.5 Slope Compensation
    5. 7.5 Device Functional Modes
      1. 7.5.1 Off
      2. 7.5.2 Startup
      3. 7.5.3 On
      4. 7.5.4 Fault
      5. 7.5.5 Disabled
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Application
      2. 8.2.2 Design Requirements
      3. 8.2.3 Detailed Design Procedure
        1. 8.2.3.1 Input Bulk Capacitance with Minimum Bulk Voltage
        2. 8.2.3.2 Transformer Turns Ratio and Inductance
        3. 8.2.3.3 Current Sense and Slope Compensation Network
        4. 8.2.3.4 Output Capacitors
        5. 8.2.3.5 VDD Capacitance, CVDD
      4. 8.2.4 Application Performance Plots
        1. 8.2.4.1 Startup
        2. 8.2.4.2 Load Transients
        3. 8.2.4.3 Q1 Drain Voltage Evaluation
      5. 8.2.5 What to Do and What Not to Do
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

6.6 Switching Characteristics

Unless otherwise specified, VDD = 20 V; VFB = 2.3 V; VFLT = 2 V; TA = 25 ℃; CDRV = 1000 pF
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
DRV PIN (1)
trise Drive voltage rise time VDD > 12 V, 10-90% Rise time CLOAD = 1000 pF 120 ns
tfall Drive voltage fall time 90-10% Fall time CLOAD = 1000 pF 20 ns
OSCILLATOR AND FREQUENCY FOLDBACK
fsw Switching frequency UCC287501/2/3/4 (65 kHz version) VFB = 3.5 V 130 kHz
UCC287505/6/7/8 (100 kHz version) VFB = 3.5 V 200 kHz
V1norm < VFB Frequency Increase kHz
UCC287501/2/3/4
-40℃ < TJ < 125℃
V2foldback < VFB < V1norm		 56 65 73 kHz
UCC287505/6/7/8
-40℃ < TJ < 125℃
V2foldback < VFB < V1norm		 87 100 113 kHz
V3burst < VFB < V2foldback Frequency Foldback kHz
V4stop < VFB < V3burst 25 kHz
VFB < Vburst Burst Mode Operation kHz
Dmax Max Duty Cycle 80 %
fdither(range) Frequency modulation (EMI dither) range ± 5 %
Tdither Frequency modulation period (EMI dither) From peak to peak fsw 4.4 ms
(1) Specified by design, not production tested.