SLOS066AD September   1975  – October 2024 LM124 , LM124A , LM124M , LM224 , LM224A , LM224K , LM224KA , LM2902 , LM2902B , LM2902BA , LM2902K , LM2902KAV , LM2902KV , LM324 , LM324A , LM324B , LM324BA , LM324K , LM324KA

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 - LM324B and LM324BA
    6. 5.6  Electrical Characteristics - LM2902B and LM2902BA
    7. 5.7  Electrical Characteristics for LM324, LM324K, LM224, LM224K, and LM124
    8. 5.8  Electrical Characteristics for LM2902, LM2902K, LM2902KV and LM2902KAV
    9. 5.9  Electrical Characteristics for LM324A, LM324KA, LM224A, LM224KA, and LM124A
    10. 5.10 Operating Conditions
    11. 5.11 Typical Characteristics
    12. 5.12 Typical Characteristics: All Devices Except B and BA Versions
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Unity-Gain Bandwidth
      2. 7.3.2 Slew Rate
      3. 7.3.3 Input Common Mode Range
    4. 7.4 Device Functional Modes
  9. 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
      3. 8.2.3 Application Curve
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Examples
  10. 9 Device and Documentation Support
    1. 9.1 Receiving Notification of Documentation Updates
    2. 9.2 Support Resources
    3. 9.3 Trademarks
    4. 9.4 Electrostatic Discharge Caution
    5. 9.5 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information
    1. 11.1 Package Option Addendum
    2. 11.2 Tape and Reel Information

8.4.1 Layout Guidelines

For best operational performance of the device, use good PCB layout practices, including:

  • Noise can propagate into analog circuitry through the power pins of the circuit as a whole, as well as the operational amplifier. 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.
  • To reduce parasitic coupling, run the input traces as far away from the supply or output traces as possible. If it is not possible to keep them separate, it is much better to 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. Keeping RF and RG close to the inverting input minimizes parasitic capacitance, as shown in Section 8.4.2.
  • 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.