SBOS998C June   2021  – March 2022 BUF802

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and 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: Wide Bandwidth Mode
    6. 6.6 Electrical Characteristics: Low Quiescent Current Mode
    7. 6.7 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Input and Output Over-Voltage Clamp
      2. 8.3.2 Adjustable Quiescent Current
      3. 8.3.3 ESD Structure
    4. 8.4 Device Functional Modes
      1. 8.4.1 Buffer Mode (BF Mode)
      2. 8.4.2 Composite Loop Mode (CL Mode)
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Oscilloscope Front-End Amplifier Design
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Transforming a Wide-Bandwidth, 50 Ω Input Signal Chain to High-Input Impedance
        1. 9.2.2.1 Detailed Design Results
        2. 9.2.2.2 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 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

8.4 Device Functional Modes

GUID-20210216-CA0I-VSPM-NLZ5-QT7GGP7C67HN-low.gifFigure 8-9 Main Path and Auxiliary Path

The BUF802 has been designed to operate in two modes, Buffer Mode (BF Mode) and Composite Loop Mode (CL Mode):

In BF Mode, the BUF802 uses the JFET, output driver and bipolar transistors in the Main Path to reproduce the signal, applied on IN, at the output of the BUF802. Figure 8-9 shows the Main Path and the Auxiliary Path of the BUF802. The BUF802 can operate from DC to high-frequency and can therefore be used as a standalone buffer. While being used in BF Mode, only the Main Path of the BUF802 is used.

In CL Mode, the BUF802 utilizes the Auxiliary signal path and the Main Path to control the output voltage. As the name suggests in the Composite Loop Mode, the BUF802 is used in a composite loop with a precision amplifier to achieve DC precision and a wide, large-signal bandwidth simultaneously. The composite loop splits the applied signal to low-frequency and high-frequency components and passes them over to different circuits with suitable transfer function. The low-frequency and high-frequency signal components then recombine inside the BUF802 and are repoduced at the OUT pin.