SGLS183C August   2003  – July 2025 UCC2808A-1Q1 , UCC2808A-2Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configurations and Functions
  7. 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
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Pin Descriptions
        1. 7.3.1.1 COMP Pin
        2. 7.3.1.2 OUTA and OUTB Pins
        3. 7.3.1.3 RC Pin
        4. 7.3.1.4 VDD Pin
    4. 7.4 Device Functional Modes
      1. 7.4.1 VCC
      2. 7.4.2 Push-Pull or Half-Bridge Function
  9. 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
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Support Resources
    3. 9.3 Trademarks
    4. 9.4 Electrostatic Discharge Caution
    5. 9.5 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

3 Description

The UCC2808A-xQ1 is a family of BiCMOS push-pull pulse-width modulators that are high-speed and low-power. The UCC2808A-xQ1 contains all of the control and drive circuitry required for off-line or DC-to-DC fixed frequency current-mode switching power supplies with a minimal external part count.

The UCC2808A-xQ1 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 60ns to 200ns, depending on the values of the timing capacitor and resistors, thus limiting each output stage duty cycle to less than 50%.

The UCC2808A-xQ1 family offers a variety of package options and choice of undervoltage lockout levels. The family has UVLO thresholds and hysteresis options for off-line and battery powered systems. Thresholds are shown in the orderable information table.

The UCC2808A-xQ1 is an enhanced version of the UCC2808 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.

Table 3-1 Package Information
DEVICE PACKAGE(1) PACKAGE SIZE(2)
UCC2808AQDR-1Q1 D (SOIC, 8) 4.90mm × 6.00mm
UCC2808AQDR-2Q1
(1) For more information, see Section 11.
(2) The package size (length × width) is a nominal value and includes pins, where applicable.
UCC2808A-1Q1 UCC2808A-2Q1