SLUS495J August   2001  – December 2023 UCC29002 , UCC39002

PRODUCTION DATA  

  1.   1
  2. 1Features
  3. 2Applications
  4. 3Description
  5. 4Pin Configuration and Functions
    1.     Pin Functions
  6. 5Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Differential Current-Sense Amplifier (CS+, CS−, CSO)
      2. 6.3.2 Load-Share Bus Driver Amplifier (CSO, LS)
      3. 6.3.3 Load-Share Bus Receiver Amplifier (LS)
      4. 6.3.4 Error Amplifier (EAO)
      5. 6.3.5 Adjust Amplifier Output (ADJ)
      6. 6.3.6 Enable Function (CS+, CS−)
      7. 6.3.7 Fault Protection on LS Bus
      8. 6.3.8 Start-Up and Adjust Logic
      9. 6.3.9 Bias Input and Bias_OK Circuit (VDD)
    4. 6.4 Device Functional Modes
      1. 6.4.1 Start-Up Mode
      2. 6.4.2 Normal Running Mode
      3. 6.4.3 Fault Mode
      4. 6.4.4 Disabled Mode
  8. 7Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Paralleling the Power Modules
    3. 7.3 Typical Application
      1. 7.3.1 Measuring the Voltage Loop of a Power Module
      2. 7.3.2 Detailed Design Procedure
        1. 7.3.2.1 The Shunt Resistor
        2. 7.3.2.2 The CSA Gain
        3. 7.3.2.3 Determining RADJ
        4. 7.3.2.4 Error Amplifier Compensation
      3. 7.3.3 Application Curve
    4. 7.4 Power Supply Recommendations
    5. 7.5 Layout
      1. 7.5.1 Layout Guidelines
      2. 7.5.2 Layout Example
  9. 8Device and Documentation Support
    1. 8.1 Receiving Notification of Documentation Updates
      1. 8.1.1 Documentation Support
    2. 8.2 Related Links
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. 9Revision History
  11.   Mechanical, Packaging, and Orderable Information

6.3.1 Differential Current-Sense Amplifier (CS+, CS−, CSO)

The UCC29002 device features a high-gain and high-precision amplifier to measure and amplify the voltage across a low-value current-sense resistor. Because the amplifier is fully uncommitted, the current-sense gain is user-programmable. The current-sense amplifier is not unity-gain stable and must have a minimum gain of 3.

The extremely-low input offset voltage of the UCC29002 current-sense amplifier makes it suitable to measure current information across a low-value resistance to reduce power loss. Furthermore, the amplifier's input common-mode range includes the ground and positive supply rails (GND and VDD) of the UCC29002. Accordingly, the current-sense resistor can be placed either in the ground return path or in the positive output rail of the power supply VOUT as long as VOUT ≤ VVDD.