SNOSB14E August   2009  – July 2024 LPV521

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
    4. 6.4 Device Functional Modes
      1. 6.4.1 Input Stage
      2. 6.4.2 Output Stage
  8. 7 Applications and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Driving Capacitive Load
      2. 7.1.2 EMI Suppression
    2. 7.2 Typical Applications
      1. 7.2.1 60Hz Twin T-Notch Filter
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
        3. 7.2.1.3 Application Curve
      2. 7.2.2 Portable Gas Detection Sensor
        1. 7.2.2.1 Design Requirements
        2. 7.2.2.2 Detailed Design Procedure
        3. 7.2.2.3 Application Curve
      3. 7.2.3 High-Side Battery Current Sensing
        1. 7.2.3.1 Design Requirements
        2. 7.2.3.2 Detailed Design Procedure
        3. 7.2.3.3 Application Curve
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Development Support
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
    6. 8.6 Electrostatic Discharge Caution
    7. 8.7 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

7.4.1 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. Use bypass capacitors to reduce the coupled noise by providing low-impedance power sources local to the analog circuitry.
  • Connect low-ESR, 0.1μF 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. Physically separate digital and analog grounds paying attention to the flow of the ground current.
  • To reduce parasitic coupling, run the input traces as far away from the supply or output traces as possible. If not possible, cross the sensitive trace perpendicular as opposed to in parallel with the noisy trace.
  • Place the external components as close to the device as possible. Section 7.4.2 shows how 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.