SGLS187C September   2003  – August 2025 UCC2808A-1EP , UCC2808A-2EP

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration 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 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
  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 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

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

7.3.1.6 RC

The oscillator programming pin. The oscillator of the UCC2808A-xEP tracks VDD and GND internally, so that variations in power supply rails minimally affect frequency stability. Section 7.2 shows the oscillator block diagram.

Only two components are required to program the oscillator: a resistor (tied to the VDD and RC), and a capacitor (tied to the RC and GND). Equation 1 determines the approximate oscillator frequency.

Equation 1. f O S C I L L A T O R = 1.41 R C

where

  • frequency is in Hz
  • resistance in Ω
  • capacitance in Farads

The recommended range of the timing resistors is from 10kΩ to 200kΩ, and range of the timing capacitors is from 100pF to 1000pF. Avoid timing resistors smaller than 10kΩ.

For best performance, keep the timing capacitor lead to GND as short as possible, the timing resistor lead from VDD as short as possible, and the leads between timing components and RC as short as possible. Separate ground and VDD traces to the external timing network are encouraged.