SBOS982J june   2020  – june 2023 OPA2863 , OPA4863 , OPA863

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Device Comparison Table
  7. 6 Pin Configuration and Functions
  8. 7 Specifications
    1. 7.1  Absolute Maximum Ratings
    2. 7.2  ESD Ratings
    3. 7.3  Recommended Operating Conditions
    4. 7.4  Thermal Information: OPA863
    5. 7.5  Thermal Information: OPA2863
    6. 7.6  Thermal Information: OPA4863
    7. 7.7  Electrical Characteristics: VS = 10 V
    8. 7.8  Electrical Characteristics: VS = 3 V
    9. 7.9  Typical Characteristics: VS = 10 V
    10. 7.10 Typical Characteristics: VS = 3 V
    11. 7.11 Typical Characteristics: VS = 3 V to 10 V
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Input Stage
      2. 8.3.2 Output Stage
        1. 8.3.2.1 Overload Power Limit
      3. 8.3.3 ESD Protection
    4. 8.4 Device Functional Modes
      1. 8.4.1 Power-Down Mode
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Low-Side Current Sensing
        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 Front-End Gain and Filtering
      3. 9.2.3 Low-Power SAR ADC Driver and Reference Buffer
      4. 9.2.4 Variable Reference Generator Using MDAC
      5. 9.2.5 Clamp-On Ultrasonic Flow Meter
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
        1. 9.4.1.1 Thermal Considerations
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

9.2.5 Clamp-On Ultrasonic Flow Meter

Figure 9-6 shows how ultrasonic flow meters measure the rate of flow of a liquid using transit-time difference (t12–t21), which depends on the flow rate. Figure 9-6 shows a representative schematic for a non-intrusive ultrasonic flow meter using the OPAx863 and 12-V transducer excitation. The OPAx863 are used for the forward path as a unity-gain buffer for 12-V pulsed transducer excitation at NODE 1. At the same time, the receiver circuit at NODE 2 (which also uses the OPAx863) first provides an ac-gain followed by a dc-level shift to lead to the PGA, ADC, and processor within the MSP430™ microcontroller.

NODE 2 and NODE 1 use similar transmit and receive circuits (discussed previously) for the reverse path. The OPAx863 wide GBW of 50 MHz introduces minimal phase-delay and low-noise for excellent flow rate measurement. The amplifier stays in power-down mode for a majority of the time in battery-powered systems. This configuration results in very small average system-level power consumption and prolonged battery lifetime with the 1.5‑µA (maximum) power-down mode quiescent current with a 3-V supply. The transmit and receive signal chains are connected to the same point at the respective node transducers. Therefore, the OPAx863 12.6-V supply voltage capability enables 12-V transducer excitation without any damage to the front-end, or a need for external switches, thus enabling a more compact solution. These specifications make the OPAx863 an excellent choice for flow measurements in large diameter pipes and non-intrusive flow meters. The TIDM-02003 reference design discusses an ultrasonic gas flow sensing subsystem which uses high-speed amplifiers for front-end amplification.

GUID-76FEEB03-A2DE-455F-A925-B66249FDBF0B-low.gif Figure 9-6 Non-Intrusive Ultrasonic Flow Meter