SBOS777D November   2016  – July 2020 OPA2388 , OPA388 , OPA4388

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information: OPA388
    5. 6.5 Thermal Information: OPA2388
    6. 6.6 Thermal Information: OPA4388
    7. 6.7 Electrical Characteristics: VS = ±1.25 V to ±2.75 V (VS = 2.5 to 5.5 V)
    8. 6.8 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Operating Voltage
      2. 7.3.2 Input Voltage and Zero-Crossover Functionality
      3. 7.3.3 Input Differential Voltage
      4. 7.3.4 Internal Offset Correction
      5. 7.3.5 EMI Susceptibility and Input Filtering
    4. 7.4 Device Functional Modes
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Bidirectional Current-Sensing
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curve
      2. 8.2.2 Single Operational Amplifier Bridge Amplifier
      3. 8.2.3 Precision, Low-Noise, DAC Buffer
      4. 8.2.4 Load Cell Measurement
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Development Support
        1. 11.1.1.1 TINA-TI™ Simulation Software (Free Download)
        2. 11.1.1.2 TI Precision Designs
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Related Links
    4. 11.4 Receiving Notification of Documentation Updates
    5. 11.5 Support Resources
    6. 11.6 Trademarks
    7. 11.7 Electrostatic Discharge Caution
    8. 11.8 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.2 Input Voltage and Zero-Crossover Functionality

The OPAx388 input common-mode voltage range extends 0.1 V beyond the supply rails. This amplifier family is designed to cover the full range without the troublesome transition region found in some other rail-to-rail amplifiers. Operating a complementary rail-to-rail input amplifier with signals traversing the transition region results in unwanted non-linear behavior and polluted spectral content. Figure 7-1 and Figure 7-2 contrast the performance of a traditional complementary rail-to-rail input stage amplifier with the performance of the zero-crossover OPA388. Significant harmonic content and distortion is generated during the differential pair transition (such a transition does not exist in the OPA388). Crossover distortion is eliminated through the use of a single differential pair coupled with an internal low-noise charge pump. The OPAx388 maintains noise, bandwidth, and offset performance throughout the input common-mode range, thus reducing printed circuit board (PCB) and bill of materials (BOM) complexity through the reduction of power-supply rails.

GUID-1ACDB3FC-F382-49E9-B058-4E28EC7AFB50-low.pngFigure 7-1 Input Crossover Distortion Nonlinearity
GUID-639720DC-15E6-40FB-AD3B-10FFB0F94B04-low.pngFigure 7-2 Input Crossover Distortion Spectral Content

Typically, input bias current is approximately ±30 pA. Input voltages exceeding the power supplies, however, can cause excessive current to flow into or out of the input pins. Momentary voltages greater than the power supply can be tolerated if the input current is limited to 10 mA. This limitation is easily accomplished with an input resistor, as shown in Figure 7-3.

GUID-6F5FAAF0-F4B3-47AD-84AE-6269C70F267F-low.gif Figure 7-3 Input Current Protection