SBOSA11A March   2020  – March 2021 OPA2206

PRODUCTION DATA  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Pin Configuration and Functions
  6. Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information: OPA2206
    5. 6.5 Electrical Characteristics: VS = ±5 V
    6. 6.6 Electrical Characteristics: VS = ±15 V
    7. 6.7 Typical Characteristics
  7. Parameter Measurement Information
    1. 7.1 Typical Specifications and Distributions
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Input Overvoltage Protection
      2. 8.3.2 Input Offset Trimming
      3. 8.3.3 Lower Input Bias With Super-Beta Inputs
      4. 8.3.4 Overload Power Limiter
      5. 8.3.5 EMI Rejection
    4. 8.4 Device Functional Modes
  9. Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Voltage Attenuator
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Discrete, Two-Op-Amp Instrumentation Amplifier
      3. 9.2.3 Input Buffer and Protection for ADC Driver
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Development Support
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support 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

Detailed Design Procedure

In this design, a ±10-V, 10-kHz bandwidth, bipolar signal is attenuated and converted to a single-ended signal and filtered by a 3rd-order Butterworth filter to drive a single-ended analog-to-digital converter (ADC). By using the OPA2206, the input of the signal chain is protected from overvoltages up to 40 V beyond either supply. This signal-chain design is common for programmable logic controllers (PLCs), low-power data acquisition systems (DAQs) and field instruments where high precision, low power and signal fault protection are needed.

The OPA2206 was selected for this application because of the high supply range, high dc precision (2-µV offset and 0.04-µV/°C offset drift), and low power consumption (220-µA quiescent current) that minimizes thermal dissipation requirements. Because of the internal OVP topology, the device provides better dc and ac accuracy under normal operating conditions compared to passive external protection and results in a smaller system solution. Be sure to connect a zener diode between each supply to ground to provide a return path for the current that is generated during a fault condition.

The first stage of the signal chain is an attenuator and level-shifter. The input signal to this stage is bipolar ±10 V that is attenuated to ±2.5 V, and then level-shifted so that the output is a single-ended, 0-V to 5-V signal. The feedback and gain resistors were selected as 20 kΩ and 80 kΩ, respectively. Thus, the combined impedance is 100 kΩ, which lowers the input current to the signal chain, and minimizes errors resulting from higher output impedance sensors.

The second stage of the signal chain uses the second channel of the OPA2206 to create a 3rd-order Butterworth filter with a –3-dB response of 20 kHz. For more information on filter design, refere to Texas Instrument's filter design tool.

The output of this signal chain is shown in Figure 9-2 and the filter response is shown in Figure 9-3.