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

3.5.1 Measuring the Response of an ECR and CER ESD Cell

Figure 3-10 shows a circuit setup to measure the ESD behavior of LM2904B. Note that a 100Ω series limiting resistor is used to make sure that the device does not see an input current greater than 10mA. This device has a ECR ESD cell that is level triggered at approximately 65V.

LM2904B Diode Measurement CircuitFigure 3-10 LM2904B Diode Measurement Circuit

Figure 3-11 shows the raw measurement of the ESD cell in the time domain. The ESD cell drops the voltage down to approximately 30V after forcing a 75V input.

LM2904B Snapback Measurement Figure 3-11 LM2904B Snapback Measurement