SLUS456F April   1999  – July 2018 UCC2808A-1 , UCC2808A-2 , UCC3808A-1 , UCC3808A-2

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Application
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 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 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagrams
    3. 7.3 Feature Description
      1. 7.3.1 Pin Descriptions
        1. 7.3.1.1 COMP
        2. 7.3.1.2 CS
        3. 7.3.1.3 FB
        4. 7.3.1.4 GND
        5. 7.3.1.5 OUTA and OUTB
        6. 7.3.1.6 RC
        7. 7.3.1.7 VDD
    4. 7.4 Device Functional Modes
      1. 7.4.1 VCC
      2. 7.4.2 Push-Pull or Half-Bridge Function
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Related Links
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Community Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • D|8
  • PW|8
Thermal pad, mechanical data (Package|Pins)
Orderable Information

3 Description

The UCCx808A devices are a family of BiCMOS push-pull, high-speed, low-power, pulse-width modulators. The UCCx808A contains all of the control and drive circuitry required for off-line or DC-to-DC fixed frequency current-mode switching power supplies with minimal external parts count.

The UCCx808A dual-output drive stages are arranged in a push-pull configuration. Both outputs switch at half the oscillator frequency using a toggle flip-flop. The dead time between the two outputs is typically 60 ns to 200 ns depending on the values of the timing capacitor and resistors, thus limiting each output stage duty cycle to less than 50%.

The UCCx808A family offers a variety of package options, temperature range options, and choice of undervoltage lockout levels. The family has UVLO thresholds and hysteresis options for off-line and battery-powered systems.

The UCCx808A is an enhanced version of the UCC3808 family. The significant difference is that the A versions feature an internal discharge transistor from the CS pin to ground, which is activated each clock cycle during the oscillator dead time. The feature discharges any filter capacitance on the CS pin during each cycle and helps minimize filter capacitor values and current sense delay.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
UCC2808A-1, UCC2808A-2, UCC3808A-2 SOIC (8) 4.90 mm × 3.91 mm
PDIP (8) 9.81 mm × 6.35 mm
TSSOP (8) 3.00 mm × 4.40 mm
UCC3808A-1 SOIC (8) 4.90 mm × 3.91 mm
PDIP (8) 9.81 mm × 6.35 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.