SBOS724 September   2015 OPA1688

UNLESS OTHERWISE NOTED, this document contains PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Device Comparison Table
  6. Device Family Comparison Table
  7. Pin Configuration and Functions
  8. Specifications
    1. 8.1 Absolute Maximum Ratings
    2. 8.2 ESD Ratings
    3. 8.3 Recommended Operating Conditions
    4. 8.4 Thermal Information: OPA1688
    5. 8.5 Thermal Information: OPA1689
    6. 8.6 Electrical Characteristics
    7. 8.7 Typical Characteristics: Table of Graphs
    8. 8.8 Typical Characteristics
  9. Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 EMI Rejection
      2. 9.3.2 Phase-Reversal Protection
      3. 9.3.3 Capacitive Load and Stability
    4. 9.4 Device Functional Modes
      1. 9.4.1 Common-Mode Voltage Range
      2. 9.4.2 Electrical Overstress
      3. 9.4.3 Overload Recovery
  10. 10Applications and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
      3. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Development Support
        1. 13.1.1.1 TINA-TI (Free Software Download)
    2. 13.2 Documentation Support
      1. 13.2.1 Related Documentation
    3. 13.3 Related Links
    4. 13.4 Community Resources
    5. 13.5 Trademarks
    6. 13.6 Electrostatic Discharge Caution
    7. 13.7 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

12 Layout

12.1 Layout Guidelines

For best operational performance of the device, use good printed circuit board (PCB) layout practices, including:

  • Noise can propagate into analog circuitry through the power pins of the circuit as a whole and the op amp itself. Bypass capacitors are used to reduce the coupled noise by providing low-impedance power sources local to the analog circuitry.
    • Connect low-ESR, 0.1-µF ceramic bypass capacitors between each supply pin and ground, placed as close to the device as possible. A single bypass capacitor from V+ to ground is applicable for single-supply applications.
  • Separate grounding for analog and digital portions of circuitry is one of the simplest and most-effective methods of noise suppression. One or more layers on multilayer PCBs are usually devoted to ground planes. A ground plane helps distribute heat and reduces EMI noise pickup. Make sure to physically separate digital and analog grounds, paying attention to the flow of the ground current. For more detailed information, see SLOA089, Circuit Board Layout Techniques.
  • In order to reduce parasitic coupling, run the input traces as far away from the supply or output traces as possible. If these traces cannot be kept separate, crossing the sensitive trace perpendicularly is much better than in parallel with the noisy trace.
  • Place the external components as close to the device as possible. As illustrated in Figure 55, keeping RF and RG close to the inverting input minimizes parasitic capacitance.
  • Keep the length of input traces as short as possible. Always remember that the input traces are the most sensitive part of the circuit.
  • Consider a driven, low-impedance guard ring around the critical traces. A guard ring can significantly reduce leakage currents from nearby traces that are at different potentials.

12.2 Layout Example

OPA1688 OPA1689 layout_example_bos620.gif Figure 55. Operational Amplifier Board Layout for a Noninverting Configuration