SLOSEE7 May   2025 OPA810-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics: 24V
    6. 6.6 Electrical Characteristics: 5V
    7. 6.7 Typical Characteristics: VS = 24V
    8. 6.8 Typical Characteristics: VS = 5V
    9. 6.9 Typical Characteristics: ±2.375V to ±12V Split Supply
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Architecture
      2. 7.3.2 ESD Protection
    4. 7.4 Device Functional Modes
      1. 7.4.1 Split-Supply Operation (±2.375V to ±13.5V)
      2. 7.4.2 Single-Supply Operation (4.75V to 27V)
  9. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Amplifier Gain Configurations
      2. 8.1.2 Selection of Feedback Resistors
      3. 8.1.3 Noise Analysis and the Effect of Resistor Elements on Total Noise
    2. 8.2 Typical Applications
      1. 8.2.1 Transimpedance Amplifier
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Multichannel Sensor Interface
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
        1. 8.4.1.1 Thermal Considerations
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • DBV|5
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.2.1.2 Detailed Design Procedure

Designs that require high bandwidth from a large area detector with relatively high transimpedance gain benefit from the low input voltage noise of the OPA810-Q1. This input voltage noise is peaked up over frequency by the diode source capacitance, and can (in many cases) become the limiting factor to input sensitivity. The key elements to the design are the expected diode capacitance (CD) with the reverse bias voltage (VBIAS) applied, the desired transimpedance gain, RF, and the GBWP for the OPA810-Q1 (70MHz). Figure 8-12 shows a transimpedance circuit with the parameters as described in Table 8-2. With these three variables set (and including the parasitic input capacitance for the OPA810-Q1 and the printed circuit board (PCB) added to CD), the feedback capacitor value (CF) can be set to control the frequency response. The Transimpedance Considerations for High-Speed Amplifiers application report discusses using high-speed amplifiers for transimpedance applications. Set the feedback pole according to Equation 9 to achieve a maximally-flat second-order Butterworth frequency response:

Equation 9. 12πRFCIN = GBWP4πRFCD

The input capacitance of the amplifier is the sum of the common-mode and differential capacitance (2.0 + 0.5)pF. The parasitic capacitance from the photodiode package and the PCB is approximately 0.3pF. Using Equation 5 gives a total input capacitance of CD = 22.8pF. From Equation 9, set the feedback pole at 1.55MHz. Setting the pole at 1.55MHz requires a total feedback capacitance of 1.03pF.

Equation 10 shows the approximate –3dB bandwidth of the transimpedance amplifier circuit:

Equation 10. f-3dB = GBWP2πRFCDHz

Equation 10 estimates a closed-loop bandwidth of 2.19MHz. Figure 8-13 and Figure 8-14 show the loop-gain magnitude and phase plots from the TINA-TI simulations of the transimpedance amplifier circuit of Figure 8-12. The 1/β gain curve has a zero from RF and CIN at 70kHz and a pole from RF and CF canceling the 1/β zero at 1.5MHz, resulting in a 20dB per decade rate-of-closure at the loop-gain crossover frequency (the frequency where AOL equals 1/β), providing a stable circuit. A phase margin of 62° is obtained with a closed-loop bandwidth of 3MHz and a 100kΩ transimpedance gain.