SBOS629A April   2018  – July 2018 OPA858

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      High-Speed Time-of-Flight Receiver
      2.      Photodiode Capacitance vs. Bandwidth and Noise
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin 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
    6. 7.6 Typical Characteristics
  8. 8 Parameter Measurement Information
    1. 8.1 Parameter Measurement Information
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Input and ESD Protection
      2. 9.3.2 Feedback Pin
      3. 9.3.3 Wide Gain-Bandwidth Product
      4. 9.3.4 Slew Rate and Output Stage
      5. 9.3.5 Current Noise
    4. 9.4 Device Functional Modes
      1. 9.4.1 Split-Supply and Single-Supply Operation
      2. 9.4.2 Power-Down Mode
  10. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 Using the OPA858 as a Transimpedance Amplifier
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
      3. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Receiving Notification of Documentation Updates
    2. 13.2 Community Resources
    3. 13.3 Trademarks
    4. 13.4 Electrostatic Discharge Caution
    5. 13.5 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

9.3.4 Slew Rate and Output Stage

In addition to wide bandwidth, the OPA858 features a high slew rate of 2000 V/µs . The slew rate is a critical parameter in high-speed pulse applications with narrow sub 10-ns pulses such as Optical Time-Domain Reflectometry (OTDR) and LIDAR. The high slew rate of the OPA858 implies that the device accurately reproduces a 2-V, sub-ns pulse edge as seen in Figure 20. The wide bandwidth and slew rate of the OPA858 make it an ideal amplifier for high-speed, signal-chain front ends.

Figure 52 shows the open-loop output impedance of the OPA858 as a function of frequency. To achieve high slew rates and low output impedance across frequency, the output swing of the OPA858 is limited to approximately 3 V. The OPA858 is typically used in conjunction with high-speed pipeline ADCs and flash ADCs that have limited input ranges. Therefore, the OPA858 output swing range coupled with the class-leading voltage noise specification maximizes the overall dynamic range of the signal chain.

OPA858 D601_SBOS852.gifFigure 52. Open-Loop Output Impedance (ZOL) vs Frequency