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

7.3.4 Power On/Off Glitch

When power is turned on or off, most analog amplifiers generate some glitching of the output because of internal circuit thresholds and capacitive charges. Characteristics of the supply voltage, as well as its rise and fall time, directly influence output glitches. Load resistance and capacitive load also affect the amplitude.

The output disable control (OD) cannot fully suppress glitches during power-on and power-off, but reduces the energy significantly. The glitch consists of a small amount of current and capacitive charge (voltage) that reacts with the resistive and capacitive load. The bias current of the IA inputs that are normally connected to the output also generate a voltage across the load.

Figure 38 indicates no glitches when transitioning between disable and enable. This measurement is made with a load resistance of 1 kΩ and tested in the circuit configuration of Figure 40.

XTR305 ai_tc_od_toggle_bos336.gifFigure 38. Output Signal During Toggle of OD

When the power is off or with low supply, the output is diode clamped to the momentary supply voltage, but can float while output disabled within those limits unless terminated. Only an external switch (relays or opto-relays) can isolate the output under such conditions. Refer to Figure 39 for an illustration of this configuration. The same consideration applies if low impedance zero output is required, even during power off.

XTR305 ai_output_opto-relay_bos336.gifFigure 39. Example for Opto-Relay Output Isolation