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

8.2.2.2 Current Output Mode

The XTR305 does not require a shunt resistor for current control because it uses a precise current mirror arrangement.

In current output mode (M1 connected low, or left unconnected and M2 connected high), a precise copy of 1/10th of the output is internally routed back to the summing junction of the OPA through a multiplexer, closing the control loop for the output current.

The OPA driver can deliver more than ±24 mA within a wide output voltage range. An open-output condition or high-impedance load that prevents the flow of the required current activates the EFLD flag and the IA can become overloaded and draw greater than 7-mA saturation current.

While in current output mode, a current (IIA) that is proportional to the voltage at the IA input is routed to IAOUT and can be used to monitor the load voltage. A resistor converts this current into voltage. This arrangement makes level shifting easy.

Alternatively, the IA can be used as an independent monitoring channel. If this output is not used, connect it to GND to maintain proper function of the monitor stage, as shown in Figure 42.

XTR305 ai_iout_mode_simple_bos336.gifFigure 42. Simplified Current Output Mode Configuration

The transconductance (gain) can be set by the resistor, RSET, according to Equation 3:

Equation 3. XTR305 q_iout_rset_bos336.gif

or when adding an offset VREF to get bidirectional output with a single-ended input shown in Equation 4:

Equation 4. XTR305 q_iout_rset02_bos336.gif