SBOS998D June   2021  – July 2025 BUF802

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    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 Wide Bandwidth Mode
    6. 5.6 Electrical Characteristics Low Quiescent Current Mode
    7. 5.7 Typical Characteristics
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Input and Output Overvoltage Clamp
      2. 7.3.2 Adjustable Quiescent Current
      3. 7.3.3 ESD Structure
    4. 7.4 Device Functional Modes
      1. 7.4.1 Buffer Mode (BF Mode)
      2. 7.4.2 Composite Loop Mode (CL Mode)
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Oscilloscope Front-End Amplifier Design
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Transforming a Wide-Bandwidth, 50‑Ω Input Signal Chain to High-Input Impedance
        1. 8.2.2.1 Detailed Design Procedure
        2. 8.2.2.2 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)
  • RGT|16
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.2.2.1 Detailed Design Procedure

TIDA-01022 reference design primarily focuses on a multichannel high-speed analog front-end, which is typically used in end equipment, such as a digital storage oscilloscope (DSO), wireless communication test equipment (WCTE), and radars. A 50‑Ω input data-acquisition (DAQ) signal chain, such as the TIDA-01022, is convertible into a high-input impedance DAQ system by inserting the BUF802 at the front.

TIDA-01022 features the following:

  • The LMH5401 is a high-performance, differential amplifier with a usable bandwidth from dc to 2 GHz. The device is used as single-to-differential conversion amplifier in this signal chain. The device offers excellent linearity performance at a fixed 12-dB gain.
  • The LMH6401LMH6401 is a wideband digitally controlled variable-gain, differential in and differential out, amplifier. The noise and distortion performance are optimized to drive ultra-wideband analog-to-digital converters (ADCs). The device offers dc to 4.5-GHz bandwidth with a gain range from –6 dB to 26 dB in 1‑dB steps. The gain is controlled using a standard serial peripheral interface (SPI).
  • The ADC12DJ5200RF is a 12‑bit, gigasample ADC that directly samples input frequencies from dc to greater than 10 GHz. The ADC12DJ5200RF is configurable as a dual-channel, 5.2‑GSPS ADC or single-channel, 10.4‑GSPS ADC.

The BUF802 along with offering high-input impedance and low-noise for the front-end amplifier, holds capability of driving matched loads of 50 Ω, making this device easy to retrofit with predesigned analog front-end signal chains. Figure 8-7 to Figure 8-9 shows the comparison of native performance of the TI design TIDA-01022 and performance achieved post addition of the BUF802 at the front-end. Adding the BUF802 at the input of TIDA-01022 translates the original 50‑Ω input impedance TI design to a high-input impedance DAQ signal chain. Figure 8-6 shows a simplified schematic of the BUF802 + TIDA-01022.