SGLS318A November   2005  – November 2015 UC2854B-EP

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  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 Multiply/Square and Divide
      2. 8.3.2 Voltage Amplifier
      3. 8.3.3 Current Amplifier
      4. 8.3.4 Miscellaneous
    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  Switching Frequency
        2. 9.2.2.2  Inductor Selection
        3. 9.2.2.3  Output Capacitor
        4. 9.2.2.4  Switch and Diode
        5. 9.2.2.5  Current Sensing
        6. 9.2.2.6  Peak Current Limit
        7. 9.2.2.7  Multiplier Set-up
        8. 9.2.2.8  Feedforward Voltage
        9. 9.2.2.9  Multiplier Input Current
        10. 9.2.2.10 Oscillator Frequency
        11. 9.2.2.11 Current Error Amplifier Compensation
        12. 9.2.2.12 Voltage Error Amplifier Compensation
        13. 9.2.2.13 Feedforward Voltage Divider Filter Capacitors
        14. 9.2.2.14 Design Procedure Summary
      3. 9.2.3 Application Curve
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Community Resources
    2. 12.2 Trademarks
    3. 12.3 Electrostatic Discharge Caution
    4. 12.4 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

1 Features

  • Controlled Baseline
    • One Assembly/Test Site, One Fabrication Site
  • Extended Temperature Performance of −55°C to 125°C
  • Enhanced Diminishing Manufacturing Sources (DMS) Support
  • Enhanced Product-Change Notification
  • Qualification Pedigree (1)
  • Controls Boost PWM to Near-Unity Power Factor
  • Limits Line Current Distortion to <3%
  • World-Wide Operation Without Switches
  • Accurate Power Limiting
  • Fixed-Frequency Average Current-Mode Control
  • High Bandwidth (5 MHz), Low-Offset Current Amplifier
  • Integrated Current- and Voltage Amplifier Output Clamps
  • Multiplier Improvements: Linearity, 500 mV VAC Offset (Eliminates External Resistor), 0 V to 5 V Multout Common-Mode Range
  • VREF GOOD Comparator
  • Faster and Improved Accuracy ENABLE Comparator
  • UVLO Options (16 V/10 V or 10.5 V/10 V)
  • 300-μA Start-Up Supply Current
(1) Component qualification in accordance with JEDEC and industry standards to ensure reliable operation over an extended temperature range. This includes, but is not limited to, Highly Accelerated Stress Test (HAST) or biased 85/85, temperature cycle, autoclave or unbiased HAST, electromigration, bond intermetallic life, and mold compound life. Such qualification testing should not be viewed as justifying use of this component beyond specified performance and environmental limits.

2 Applications

    Industrial Lighting

3 Description

The UC2854B products are pin compatible enhanced versions of the UC2854. Like the UC2854, these products provide all of the functions necessary for active power factor corrected preregulators. The controller achieves near unity power factor by shaping the ac-input line current waveform to correspond to the ac-input line voltage. To do this the UC2854B uses average current mode control. Average current mode control maintains stable, low distortion sinusoidal line current without the need for slope compensation, unlike peak current mode control.

A 1% 7.5-V reference, fixed frequency oscillator, PWM, voltage amplifier with soft-start, line voltage feedforward (VRMS squarer), input supply voltage clamp, and over current comparator round out the list of features.

The UC2854B is available in a DW (SOIC-wide) package.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
UC2854B-EP SOIC (16) 10.30 mm × 7.50 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Block Diagram

UC2854B-EP fbd_sgls318.gif