SBOS973A June   2019  – September 2019 OPA2834

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      1-kHz FFT Plot (VOUT = 1 VRMS, RL = 100 kΩ, G = 1)
      2.      Low-Side, Current-Shunt Monitoring
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics: 3V to 5V
    6. 7.6 Typical Characteristics: Vs = 5 V
    7. 7.7 Typical Characteristics: VS = 3.0 V
    8. 7.8 Typical Characteristics: ±2.5-V to ±1.5-V Split Supply
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagrams
    3. 8.3 Feature Description
      1. 8.3.1 Input Common-Mode Voltage Range
      2. 8.3.2 Output Voltage Range
      3. 8.3.3 Low-Power Applications and the Effects of Resistor Values on Bandwidth
      4. 8.3.4 Driving Capacitive Loads
    4. 8.4 Device Functional Modes
      1. 8.4.1 Split-Supply Operation (±1.35 V to ±2.7 V)
      2. 8.4.2 Single-Supply Operation (2.7 V to 5.4 V)
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Noninverting Amplifier
      2. 9.1.2 Inverting Amplifier
    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
      2. 9.2.2 Field Transmitter Sensor Interface
      3. 9.2.3 Ultrasonic Flow Meters
      4. 9.2.4 Microphone Pre-Amplifier
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Examples
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

8.3.4 Driving Capacitive Loads

The OPA2834 drives up to a nominal capacitive load of 10 pF on the output with no special consideration and without the need of RO. When driving capacitive loads greater than 10 pF, TI recommends using a small resistor (RO) in series with the output as close to the device as possible. Without RO, output capacitance interacts with the output impedance (ZO) of the amplifier causing phase shift in the feedback loop of the amplifier reducing the phase margin. This reduction in the phase margin causes peaking in the frequency response and overshoot and ringing in the pulse response. Interaction with other parasitic elements can lead to further instability or ringing. Inserting RO isolates the phase shift from the loop gain path and restores the phase margin; however RO can limit the bandwidth slightly. Figure 49 shows a diagram of driving capacitive loads.

Figure 39 shows the test circuit and shows the recommended values of RO versus capacitive loads, CL. See Figure 40 for the frequency responses with various optimized values of RO with CL.

OPA2834 Capacitor_Drive_Section.gifFigure 49. Driving Capacitive Loads With the OPA2834