SBOS195E March   2001  – April 2018 OPA2355 , OPA3355 , OPA355

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin Functions: OPA355
    2.     Pin Functions: OPA2355
    3.     Pin Functions: OPA3355
  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: OPA355
    5. 7.5 Thermal Information: OPA2355
    6. 7.6 Thermal Information: OPA3355
    7. 7.7 Electrical Characteristics: VS = 2.7 V to 5.5 V (Single-Supply)
    8. 7.8 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 Operating Voltage
      2. 8.3.2 Enable Function
      3. 8.3.3 Output Drive
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Transimpedance Amplifier
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Optimizing The Transimpedance Circuit
        3. 9.2.1.3 Application Curve
      2. 9.2.2 High-Impedance Sensor Interface
      3. 9.2.3 Driving ADCs
      4. 9.2.4 Active Filter
    3. 9.3 Video
    4. 9.4 Wideband Video Multiplexing
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Related Links
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Community 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

9.2.1.2.1 Optimizing The Transimpedance Circuit

To achieve the best performance, select components according to the following guidelines:

  1. For lowest noise, select R(FB) to create the total required gain. Using a lower value for R(FB) and adding gain after the transimpedance amplifier generally results in poorer noise performance. R(FB) produces noise that increases with the square root of R(FB), whereas the signal increases linearly. Therefore, signal-to-noise ratio improves when all the required gain is placed in the transimpedance stage.
  2. Minimize photodiode capacitance and stray capacitance at the summing junction (inverting input). This capacitance causes the voltage noise of the op amp to amplify (increasing amplification at high frequencies). Using a low-noise voltage source to reverse-bias a photodiode can significantly reduce the capacitance. Smaller photodiodes have lower capacitance. Use optics to concentrate light on a small photodiode.
  3. Noise increases with increased bandwidth. Only use the required circuit bandwidth. Use a capacitor across the R(FB) to limit bandwidth, even if a capacitor is not required for stability.
  4. Circuit board leakage can degrade the performance of an otherwise well-designed amplifier. Clean the circuit board carefully. Control leakage by using a circuit board guard trace that encircles the summing junction and drives at the same voltage.

For additional information, see Noise Analysis of FET Transimpedance Amplifiers and Noise Analysis for High-Speed Op Amps).