SBOSA57B February   2021  – January 2023 OPA855-Q1

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 Thermal Information
    4. 7.4 Recommended Operating Conditions
    5. 7.5 Electrical Characteristics
    6. 7.6 Typical Characteristics
  8. 8 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
    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, Implementation, and Layout
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
      3. 10.2.3 Application Curves
    3. 10.3 Typical Application
      1. 10.3.1 Design Requirements
      2. 10.3.2 Detailed Design Procedure
      3. 10.3.3 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 Device Support
      1. 13.1.1 Development Support
    2. 13.2 Documentation Support
      1. 13.2.1 Related Documentation
    3. 13.3 Receiving Notification of Documentation Updates
    4. 13.4 Support Resources
    5. 13.5 Trademarks
    6. 13.6 Electrostatic Discharge Caution
    7. 13.7 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

9.2 Functional Block Diagram

The OPA855-Q1 is a classic voltage feedback operational amplifier (op amp) with two high-impedance inputs and a low-impedance output. Standard application circuits are supported, like the two basic options shown in Figure 9-1 and Figure 9-2. The resistor on the noninverting pin is used for bias current cancellation to minimize the output offset voltage. In a noninverting configuration the additional resistors on the noninverting pin add noise to the system so if SNR is critical, the resistor can be eliminated. In an inverting configuration the noninverting node is typically connected to a DC voltage, so the high-frequency noise contribution from the bias cancellation resistor can be bypassed by adding a large 1-µF capacitor in parallel to the resistor to shunt the noise. The DC operating point for each configuration is level-shifted by the reference voltage (VREF), which is typically set to midsupply in single-supply operation. VREF is typically connected to ground in split-supply applications.

GUID-58121792-32D0-492B-88A2-4246DA7E99D9-low.gif Figure 9-1 Noninverting Amplifier
GUID-94D8DE52-4636-46AB-AEEC-83BFB82E4C69-low.gif Figure 9-2 Inverting Amplifier