SLUS224H September   1994  – October 2024 UC1842A , UC1843A , UC1844A , UC1845A , UC2842A , UC2843A , UC2844A , UC2845A , UC3842A , UC3843A , UC3844A , UC3845A

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Pulse-by-Pulse Current Limiting
      2. 6.3.2 Current Sense Circuit
      3. 6.3.3 Error Amplifier Configuration
      4. 6.3.4 Undervoltage Lockout
      5. 6.3.5 Oscillator
    4. 6.4 Device Functional Modes
      1. 6.4.1 Normal Operation
      2. 6.4.2 Undervoltage Lockout (UVLO) Start-Up
      3. 6.4.3 UVLO Turnoff Mode
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Custom Design With WEBENCH® Tools
        2. 7.2.2.2 UC2842A Design Procedure
      3. 7.2.3 Application Curves
  9. 8 Power Supply Recommendations
  10. 9 Layout
    1. 9.1 Layout Guidelines
    2. 9.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Development Support
        1. 10.1.1.1 Custom Design With WEBENCH® Tools
      2. 10.1.2 Device Nomenclature
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
    3. 10.3 Related Links
    4. 10.4 Receiving Notification of Documentation Updates
    5. 10.5 Support Resources
    6. 10.6 Trademarks
    7. 10.7 Electrostatic Discharge Caution
    8. 10.8 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

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

11 Revision History

Changes from Revision G (July 2022) to Revision H (October 2024)

  • Updated the numbering format for tables, figures, and cross-references throughout the documentGo
  • Changed thermal information for D-8, D-14, and P-8 packagesGo
  • Changed the OUTPUT SECTION: Rise and fall time, typical value from 50ns to 25ns in the Electrical Characteristics sectionGo
  • Changed the OUTPUT SECTION: Output low level, typical value from 15V to 1.5V in the Electrical Characteristics sectionGo
  • Changed the PWM: maximum duty cycle of UCx842/3A, minimum value from 94% to 92% in the Electrical Characteristics sectionGo
  • Changed the PWM SECTION: maximum duty cycle of UCx844/5A, minimum value from 47% to 46% in the Electrical Characteristics sectionGo
  • Changed the TOTAL STANDBY CURRENT, VCC Zener voltage, typical value from 34V to 39V in the Electrical Characteristics sectionGo
  • Updated the Frequency vs Rt and Maximum Duty Cycle vs Rt figures in the Typical CharacteristicsGo

Changes from Revision F (October 2017) to Revision G (July 2022)

  • Updated the numbering format for tables, figures, and cross-references throughout the documentGo

Changes from Revision E (October 2017) to Revision F (October 2017)

  • Added WEBENCH links in three places, Features, Application and Implementation and Device and Documentation Support.Go
  • Added copyright information to the Simplified Application Diagram Go
  • Changed operating free-air temperature of the UC284xA changed from 125°C to 85°C. Go
  • Changed operating free-air temperature of the UC384xA changed from -40°C to 0°C. Go
  • Changed operating free-air temperature of the UC384xA changed from 85°C to 70°C. Go
  • Changed the frequency (f) calculation to the correct equation.Go
  • Changed the COUT equation to the corrected equation. Go
  • Changed the LPM equation to the corrected equation.Go
  • Added GCO(f) definition and equation.Go
  • Changed the fRHPz equation to the corrected equation.Go

Changes from Revision D (July 2011) to Revision E (July 2016)

  • Added Applications section, Device Information table, Pin Configuration and Functions section, Specifications section, Detailed Description section, Application and Implementation section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and Mechanical, Packaging, and Orderable Information section Go
  • Deleted Ordering Information Table; see POA at the end of the data sheetGo

Changes from Revision C (August 2010) to Revision D (July 2011)

  • Changed Absolute Maximum ratings table with maximum negative voltage and GND pin notes.Go

Changes from Revision B (September 2009) to Revision C (August 2010)

  • Corrected ISINK voltage.Go