SBOS492G June   2009  – August 2026 OPA2354A-Q1 , OPA354A-Q1 , OPA4354-Q1

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
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Operating Voltage
      2. 6.3.2 Rail-to-Rail Input
      3. 6.3.3 Rail-to-Rail Output
      4. 6.3.4 Output Drive
      5. 6.3.5 Video
      6. 6.3.6 Driving Analog-to-Digital Converters
      7. 6.3.7 Capacitive Load and Stability
      8. 6.3.8 Wideband Transimpedance Amplifier
    4. 6.4 Device Functional Modes
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Applications
      1. 7.2.1 Transimpedance Amplifier
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
          1. 7.2.1.2.1 Optimizing The Transimpedance Circuit
        3. 7.2.1.3 Application Curve
      2. 7.2.2 High-Impedance Sensor Interface
      3. 7.2.3 Driving ADCs
      4. 7.2.4 Active Filter
    3. 7.3 Power Supply Recommendations
      1. 7.3.1 Power Dissipation
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Documentation Support
      1. 8.1.1 Related Documentation
    2. 8.2 Receiving Notification of Documentation Updates
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

7.2.1 Transimpedance Amplifier

Wide gain bandwidth, low input bias current, low input voltage, and current noise make the OPAx354-Q1 family of devices a preferred wideband photodiode transimpedance amplifier. Low-voltage noise is important because photodiode capacitance causes the effective noise gain of the circuit to increase at high frequency.

The key elements to a transimpedance design, as shown in Figure 7-1, are the expected diode capacitance (C(D)), which must include the parasitic input common-mode and differential-mode input capacitance (4pF + 5pF); the desired transimpedance gain (R(FB)); and the gain-bandwidth (GBW) for the OPAx354-Q1 family of devices (20MHz). With these three variables set, the feedback capacitor value (C(FB)) is set to control the frequency response. C(FB) includes the stray capacitance of R(FB), which is 0.2pF for a typical surface-mount resistor.

OPA354A-Q1 OPA2354A-Q1 OPA4354-Q1 Dual-Supply Transimpedance Amplifier
A. C(FB) is optional to prevent gain peaking. C(FB) includes the stray capacitance of R(FB).
Figure 7-1 Dual-Supply Transimpedance Amplifier