SPVA018 August   2025 LM2904B

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2ESD Overview
    1. 2.1 What is Electrostatic Discharge?
      1. 2.1.1 ESD Cell Robustness in Semiconductors
  6. 3Types of ESD Cells
    1. 3.1 Dual Diode Configuration
      1. 3.1.1 Why Not Always Use Dual Diode Configuration?
    2. 3.2 Bootstrapped Diodes
    3. 3.3 Absorption Devices
      1. 3.3.1 Active Clamps
      2. 3.3.2 GCNMOS Clamps
    4. 3.4 Silicon Controlled Rectifiers
    5. 3.5 CER and ECR NPN Diodes
      1. 3.5.1 Measuring the Response of an ECR and CER ESD Cell
    6. 3.6 Comparison of ESD Cells
  7. 4How to Determine the ESD Structure of the Device from the Data Sheet
  8. 5How to Protect The System from In Circuit ESD/EOS Events
    1. 5.1 Using TVS Diodes and Series Resistance for Circuit Protection
    2. 5.2 Using Schottky Diodes for Circuit Protection
  9. 6How to Test an Op Amp in a System Level Circuit
    1. 6.1 ESD Protection Cell Advancements Over the Years
  10. 7Summary
  11. 8References

2.1 What is Electrostatic Discharge?

Electrostatic discharge (ESD) occurs when two items with a charge imbalance are brought in close proximity. There is a sudden flow of electricity between the two objects, which is called ESD. Insulators in particular are prone to developing large static charges.

ESD is the most common way that semiconductors are damaged. Looking at the voltage that ESD can generate, we see that there is a large gap between ESD discharge and human awareness. Some ICs can be damaged at 10V, but humans cannot even feel a discharge until 3500V. CMOSs and op amps are susceptible to damage at a lower voltage threshold than what humans can feel. Therefore, it is possible to damage a semiconductor without even knowing the ESD event has occurred. Static discharge arises from human handling, or contact with machines. Therefore, protecting against ESD events so that devices are not damaged is important before the application use.