SLUS872E January   2009  – February 2019 UC1842A-SP , UC1844A-SP

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin 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 Electrical Characteristics (Radiation-Improved Devices)
    7. 7.7 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 UVLO
      2. 8.3.2 Reference
      3. 8.3.3 Totem-Pole Output
    4. 8.4 Device Functional Modes
  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 Oscillator
        2. 9.2.2.2 Current Sensing and Limiting
        3. 9.2.2.3 Error Amplifier
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Feedback Traces
      2. 11.1.2 Input/Output Capacitors
      3. 11.1.3 Compensation Components
      4. 11.1.4 Traces and Ground Planes
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Related Links
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

1 Features

  • QML Class V (QMLV) Qualified, SMD 5962-86704
  • Rad-Tolerant: 30-krad(Si) TID (1)(2)
  • Optimized for Offline and DC-to-DC Converters
  • Low Start-Up Current (< 0.5 mA)
  • Trimmed Oscillator Discharge Current
  • Automatic Feed Forward Compensation
  • Pulse-by-Pulse Current Limiting
  • Enhanced Load Response Characteristics
  • Undervoltage Lockout (UVLO) With Hysteresis
  • Double-Pulse Suppression
  • High-Current Totem-Pole Output
  • Internally-Trimmed Bandgap Reference
  • 500-kHz Operation
  • Low RO Error Amplifier
    • 1. The LDR improved die is only available in the UC1843A-SP (orderable as 5962-8670409VPA). Contact factory to request an LDR-improved version of the UC1842A-SP or UC1844A-SP.
    2. Radiation tolerance is a typical value based upon initial device qualification with dose rate = 10 mrad(Si)/s. Radiation lot acceptance testing is available - contact factory for details.