SLUS336A June   1998  – December 2016 UC1854 , UC2854 , UC3854


  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Device Comparison Table
  6. Pin Configuration and Functions
  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. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
    4. 8.4 Device Functional Modes
  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. Protection Inputs
        2. Control Inputs
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Related Links
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Community Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • DW|16
  • N|16
Thermal pad, mechanical data (Package|Pins)
Orderable Information


  • Control Boost PWM to 0.99 Power Factor
  • Limit Line-Current Distortion to < 5%
  • World-Wide Operation Without Switches
  • Feedforward Line Regulation
  • Average Current-Mode Control
  • Low Noise Sensitivity
  • Low Startup Supply Current
  • Fixed-Frequency PWM Drive
  • Low-Offset Analog Multiplier and Divider
  • 1-A Totem-Pole Gate Driver
  • Precision Voltage Reference


  • Offline AC-to-DC Converters
  • Medical, Industrial, Telecom, and IT Power Supplies
  • Uninterruptible Power Supplies (UPS)
  • Appliances and White Goods


The UC1854 provides active-power factor correction for power systems that otherwise would draw non-sinusoidal current from sinusoidal power lines. This device implements all the control functions necessary to build a power supply capable of optimally using available power-line current while minimizing line-current distortion. To do this, the UC1854 contains a voltage amplifier, an analog multiplier and divider, a current amplifier, and a fixed-frequency PWM.

In addition, the UC1854 contains a power MOSFET-compatible gate driver, 7.5-V reference, line anticipator, load-enable comparator, low-supply detector, and overcurrent comparator.

The UC1854 uses average current-mode control to accomplish fixed-frequency current control with stability and low distortion. Unlike peak current-mode, average current control accurately maintains sinusoidal line current without slope compensation and with minimal response to noise transients.

The high reference voltage and high oscillator amplitude of the UC1854 minimize noise sensitivity while fast PWM elements permit chopping frequencies above 200 kHz. The UC1854 is used in single-phase and three-phase systems with line voltages that vary from 75 V to 275 V and line frequencies across the 50-Hz to 400-Hz range. To reduce the burden on the circuitry that supplies power to this device, the UC1854 features low starting supply current.

These devices are available packaged in 16-pin plastic and ceramic dual in-line packages, and a variety of surface-mount packages.

Device Information(1)

UC1854, UC2854, UC3854 SOIC (16) 7.50 mm × 10.30 mm
PLCC (20) 8.96 mm × 8.96 mm
CDIP (16) 6.92 mm × 19.56 mm
PDIP (16) 6.35 mm × 19.30 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Block Diagram

UC1854 UC2854 UC3854 page1_diagram.gif