Waveform Verification for IEC 61000-4-2 Waveshape

Notice: This information is a brief overview. For daily ESD simulator gun verifications and in-depth test information you will need to attain a copy of IEC 61000-4-2:2009.

Materials & Test Equipment

  • Oscilloscope (at least 2 GHz Analog Bandwidth)
  • Coaxial Current Target Chain
  • 20 dB attenuator (for 16kV ESD Simulators)
  • 30 dB attenuator (for 30kV ESD Simulators)
  • 4' x 4' Vertical Calibration Plane for ESD Target
  • Tripod for ESD Simulator Gun
  • Optional Faraday Cage for discharge isolation

ESD Waveshape Requirements

Waveshape in accordance to IEC 61000-4-2

Following parameters to be considered when verifying the pulse shape from the ESD generator with an oscilloscope:

  • First Peak Current
  • Rise Time (0.6 to 1.0 ns)
  • Current at 30 ns
  • Current at 60 ns

Associated Products

CST2 ESD Current Target

ESDGuns Current Target for Simulator Waveform Verification

Features:

  • Meets IEC 61000-4-2
  • DC - 4 GHz Frequency Range
  • Gold Plating Surface
  • 0.5A/V transfer impedance, ±1% (with a 20dB attenuator, 5A/V)

Keytek MZ-15/EC Minizap ESD Gun

Features:

  • Intuitive operation
  • Portable & self-contained
  • Contact mode & air discharge
  • Meets IEC 61000-4-2
  • Rechargeable battery or AC powered

Procedure

An oscilloscope must use 0% and Max thresholds in order to perform the EMC-specific measurement.

Capturing the correct waveform with the scope can only be achieved with the proper settings of the DSO. The settings need to be made to measure pulses with +/-2kV, +/-4kV, +/-6kV and +/-8kV. Four parameters need to be measured at each voltage level:
- Initial peak current
- Rise time between 10% and 90% of the initial peak
- Current value at 30ns
- Current value at 60ns

The time domain for the initial peak and rise time measurement is recommended to be set to 1ns/Div. For the current measurement at 30nS and 60ns a setting of 10ns/Div is recommended as being appropriate.

  1. Capture a Single Pulse
  2. Measure one pulse, verify rise time for positive pulses, verify fall time for negative pulses 
  3. 1 GHz, 2 GHz, or 3GHz+ scope depending on standard specification

Calculating Ratio

Calculated from the impedance and attenuation values the following equation gives the proper ratio:

Ip = 5 x Vm

where
Vm is the voltage signal measured by the DSO in Volt
V1 is the voltage measured accros the CTR 2 target
Ip is the discharge current

Therefore
V1 = 20dB x Vm = 2ohm x Ip
Ip = 20dB x Vm/2ohm

For example:
A discharge current of 7.5A will give a voltage reading of 1.5V on the DSO.

Related Information

  • ESD Simulator Gun Calibration Services
  • IEC 61000-4-2: Test Standard for Electrostatic Discharge Immunity

Calibration Diagram

Using an oscilloscope and attenuators - verify the waveform coming off your ESD gun:

Setup Oscilloscope for Waveform Verification

Note: Attenuator A should be 20 dB, Attenuator B (typically 10 dB) may not be required.