SBOS913 February   2018 XTR305

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin 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
    5. 6.5  Electrical Characteristics: Voltage Output Mode
    6. 6.6  Electrical Characteristics: Current Output Mode
    7. 6.7  Electrical Characteristics: Operational Amplifier (OPA)
    8. 6.8  Electrical Characteristics: Instrumentation Amplifier (IA)
    9. 6.9  Electrical Characteristics: Current Monitor
    10. 6.10 Electrical Characteristics: Power and Digital
    11. 6.11 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagrams
    3. 7.3 Feature Description
      1. 7.3.1 Functional Features
      2. 7.3.2 Current Monitor
      3. 7.3.3 Error Flags
      4. 7.3.4 Power On/Off Glitch
    4. 7.4 Device Functional Modes
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1  Voltage Output Mode
        2. 8.2.2.2  Current Output Mode
        3. 8.2.2.3  Input Signal Connection
        4. 8.2.2.4  Externally-Configured Mode: OPA and IA
        5. 8.2.2.5  Driver Output Disable
        6. 8.2.2.6  Driving Capacitive Loads and Loop Compensation
        7. 8.2.2.7  Internal Current Sources, Switching Noise, and Settling Time
        8. 8.2.2.8  IA Structure, Voltage Monitor
        9. 8.2.2.9  Digital I/O and Ground Considerations
        10. 8.2.2.10 Output Protection
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 VQFN Package and Heat Sinking
    4. 10.4 Power Dissipation
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

8.2.2.3 Input Signal Connection

It is possible to drive the XTR305 with a unidirectional input signal and still get a bidirectional output by adding an additional resistor, ROS, and an offset voltage signal, VREF. It can be a mid-point voltage or a signal to shift the output voltage to a desired value.

This design is illustrated in Figure 43a, Figure 43b, and Figure 43c. As with a normal operational amplifier, there are several options for offset-shift circuits. The input can be connected for inverting or noninverting gain. Unlike many op amp input circuits, however, this configuration uses current feedback, which removes the voltage relationship between the noninverting input and output potential because there is no feedback resistor.

XTR305 ai_typ_cir_op_amp_out_bos336.gifFigure 43. Circuit Options for Op Amp Output Level Shifting

The input bias current effect on the offset voltage can be reduced by connecting a resistor in series with the positive input that matches the approximate resistance at the negative input. This resistor placed close to the input pin acts as a damping element and makes the design less sensitive to RF noise. See R3 in Figure 40.