SBOS789C August   2017  – February 2020 OPA2810

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Multichannel Sensor Interface
      2.      Harmonic Distortion vs Frequency
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  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
    5. 7.5  Electrical Characteristics: 10 V
    6. 7.6  Electrical Characteristics: 24 V
    7. 7.7  Electrical Characteristics: 5 V
    8. 7.8  Typical Characteristics: VS = 10 V
    9. 7.9  Typical Characteristics: VS = 24 V
    10. 7.10 Typical Characteristics: VS = 5 V
    11. 7.11 Typical Characteristics: ±2.375 V to ±12 V Split Supply
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 OPA2810 Architecture
      2. 8.3.2 ESD Protection
    4. 8.4 Device Functional Modes
      1. 8.4.1 Split-Supply Operation (±2.375 V to ±13.5 V)
      2. 8.4.2 Single-Supply Operation (4.75 V to 27 V)
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Selection of Feedback Resistors
      2. 9.1.2 Noise Analysis and the Effect of Resistor Elements on Total Noise
    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
      2. 9.2.2 Multichannel Sensor Interface
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Thermal Considerations
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    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

9.2.2 Multichannel Sensor Interface

High-Z input amplifiers are particularly useful when interfaced with sensors that have relatively high output impedance. Such multichannel systems usually interface these sensors with the signal chain through a multiplexer. Figure 76 shows one such implementation using an amplifier for interface with each sensor, and driving into an ADC through a multiplexer. An alternate circuit, shown in Figure 77, may use a single higher GBWP and fast-settling amplifier at the output of the multiplexer. This gives rise to large signal transients when switching between channels, where the settling performance of the amplifier and maximum allowed differential input voltage limits signal chain performance and amplifier reliability, respectively.

OPA2810 BD_MutipleAmps.gifFigure 76. Multichannel Sensor Interface Using Multiple Amplifiers
OPA2810 BD_Front-Page.gifFigure 77. Multichannel Sensor Interface Using a Single Higher GBWP Amplifier

Figure 78 shows the output voltage and input differential voltage when a 8-V step is applied at the noninverting terminal of the OPA2810 configured as a unity-gain buffer of Figure 77.

OPA2810 BD_Mux_Waveform.gifFigure 78. Large-Signal Transient Response Using OPA2810

Because of the fast input transient, the amplifier is slew-limited and the inputs cease to track each other (a maximum VIN,Diff of 7V is seen in Figure 78) until the output reaches its final value and the negative feedback loop is closed. For standard amplifiers with a 0.7-1.5V maximum VIN,Diff rating, it is required to use current-limiting resistors in series with the input pins to protect from irreversible damage, which also limits the device frequency response. The OPA2810 has built-in input clamps that allow the application of as much as 7V of VIN,Diff, with no external resistors required and no damage to the device or a shift in performance specifications. Such an input-stage architecture coupled, with its fast settling performance, makes the OPA2810 a good fit for multichannel sensor multiplexed systems.