SBOS233G March   2002  – April 2018 OPA2354 , OPA354 , OPA4354

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: OPA354
    2.     Pin Functions: OPA2354
    3.     Pin Functions: OPA4354
  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: OPA354
    5. 7.5 Thermal Information: OPA2354
    6. 7.6 Thermal Information: OPA4354
    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 Rail-to-Rail Input
      3. 8.3.3 Rail-to-Rail Output
      4. 8.3.4 Output Drive
      5. 8.3.5 Video
      6. 8.3.6 Driving Analog-to-Digital converters
      7. 8.3.7 Capacitive Load and Stability
      8. 8.3.8 Wideband Transimpedance Amplifier
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Optimizing the Transimpedance Circuit
      3. 9.2.3 Application Curve
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
    3. 11.3 Power Dissipation
    4. 11.4 PowerPAD Thermally-Enhanced Package
    5. 11.5 PowerPAD Assembly Process
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
    2. 12.2 Related Links
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Community Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

8.3.8 Wideband Transimpedance Amplifier

Wide bandwidth, low input bias current, low input voltage, and current noise make the OPAx354 a preferred wideband photodiode transimpedance amplifier for low-voltage single-supply applications. 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 36) are the expected diode capacitance [including the parasitic input common-mode and differential-mode input capacitance (2 + 2) pF for the OPAx354], the desired transimpedance gain (RF), and the gain-bandwidth product (GBW) for the OPAx354 (100 MHz, typical). With these three variables set, the feedback capacitor value (CF) may be set to control the frequency response.

OPA354 OPA2354 OPA4354 ai_transimpedance_amp_bos233.gifFigure 36. Transimpedance Amplifier

To achieve a maximally flat, second-order, Butterworth frequency response, the feedback pole must be set as shown in Equation 1:

Equation 1. OPA354 OPA2354 OPA4354 q01_feedback_pole_bos233.gif

Typical surface-mount resistors have a parasitic capacitance of approximately 0.2 pF that must be deducted from the calculated feedback capacitance value. Bandwidth is calculated by Equation 2:

Equation 2. OPA354 OPA2354 OPA4354 q02_bandwidth_bos233.gif

For even higher transimpedance bandwidth, the high-speed CMOS OPA355 (200-MHz GBW) or the OPA655 (400-MHz GBW) may be used.