SBOS948F February   2019  – May 2021 BUF634A

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics: Wide-Bandwidth Mode
    6. 7.6 Electrical Characteristics: Low-Quiescent Current Mode
    7. 7.7 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Output Current
      2. 8.3.2 Thermal Shutdown
      3. 8.3.3 ESD Protection
    4. 8.4 Device Functional Modes
      1. 8.4.1 Adjustable Bandwidth
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 High-Frequency Applications
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
    1. 10.1 Power Dissipation and Thermal Considerations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 SOIC Layout Guidelines (D Package Without a Thermal Pad)
      2. 11.1.2 HSOIC Layout Guidelines (DDA Package With a Thermal Pad)
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
      2. 12.1.2 Development Support
        1. 12.1.2.1 TINA-TI (Free Software Download)
        2. 12.1.2.2 TI Precision Designs
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Support Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

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

8.1 Overview

The BUF634A device is a high-speed, unity-gain, open-loop buffer that can be used in a wide range of applications requiring large output current drive or large slew rates. The BUF634A can operate on power supplies ranging from 4.5 V to 36 V and includes an internal output current limiting feature and thermal shutdown, thereby making the device rugged and easy to use.

The bandwidth of the BUF634A can be adjusted by connecting a resistor between the V– and BW pins. Its power scaling with bandwidth makes the device suitable for use in portable battery-powered applications. See the Section 8.4.1 for a description of the relationship between bandwidth adjustment resistance and the device –3-dB bandwidth.

The BUF634A can be used in a composite loop (inside the feedback loop of op amps) to increase output current, eliminate thermal feedback, and improve capacitive load drive. See Figure 9-7 for this circuit. Decoupling the high-power output current stage from the precision amplifier gives high precision performance by eliminating thermal effects on input offset of the composite circuit. With a large slew rate of 3750 V/µs, the BUF634A can quickly reproduce its input signal at its output without adding considerable delay when used in a composite loop. When used in a composite loop, the outer amplifier controls the circuit precision and distortion performance and the buffer augments the circuit output current drive capability.

See the Section 8.2 for a simplified circuit diagram of the open-loop complementary follower design of the BUF634A.