SBOS807E December   2016  – May 2020 OPA187 , OPA2187 , OPA4187

UNLESS OTHERWISE NOTED, this document contains PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      OPAx187 Offers Precision Low-Side Current Measurement Capability
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions: OPA187
    2.     Pin Functions: OPA2187
    3.     Pin Functions: OPA4187
  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: OPA187
    5. 6.5 Thermal Information: OPA2187
    6. 6.6 Thermal Information: OPA4187
    7. 6.7 Electrical Characteristics: High-Voltage Operation
    8. 6.8 Electrical Characteristics: Low-Voltage Operation
    9. 6.9 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 Characteristics
      2. 7.3.2 Phase-Reversal Protection
      3. 7.3.3 Input Bias Current Clock Feedthrough
      4. 7.3.4 Internal Offset Correction
      5. 7.3.5 EMI Rejection
      6. 7.3.6 Capacitive Load and Stability
      7. 7.3.7 Electrical Overstress
    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 High-Side Voltage-to-Current (V-I) Converter
        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 Discrete INA + Attenuation for ADC With 3.3-V Supply
      3. 8.2.3 Bridge Amplifier
      4. 8.2.4 Low-Side Current Monitor
      5. 8.2.5 Programmable Power Supply
      6. 8.2.6 RTD Amplifier With Linearization
  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™ (Free Software Download)
        2. 11.1.1.2 TI Precision Designs
        3. 11.1.1.3 WEBENCH® Filter Designer
    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

8.2.2 Discrete INA + Attenuation for ADC With 3.3-V Supply

NOTE

The TINA-TI files shown in the following sections require that either the TINA software (from DesignSoft™) or TINA-TI software be installed. Download the free TINA-TI software from the TINA-TI web folder.

Figure 42 shows an example of how the OPA187 is used as a high-voltage, high-impedance front-end for a precision, discreet instrumentation amplifier with attenuation. The INA159 provides the attenuation that allows this circuit to easily interface with 3.3-V or 5-V analog-to-digital converters (ADCs). Click the following link to download the TINA-TI file: Discrete INA.

OPA187 OPA2187 OPA4187 ai_ina_attn_33v_OPAx187.gif
1. VOUT = VDIFF × (41 / 5) + (Ref 1) / 2.
Figure 42. Discrete INA + Attenuation for ADC With a 3.3-V Supply