4.0 Discharge Generator and Test Waveform Specifications
The characteristics of the discharge generator and its output waveform are meticulously defined to guarantee that the ESD pulse applied during the test is a consistent and accurate representation of a real-world electrostatic event. This standardization of the test apparatus is essential for achieving repeatable and comparable results across different tests and laboratories.
The mandated discharge generator must conform to the following essential electrical characteristics:
- Energy storage capacitance (Cs + Cd): 150 pF ± 10%
- Discharge resistance (Rd): 330 Ω ± 10%
- Charging resistance (Rc): 50 MΩ to 100 MΩ
- Output voltage tolerance: ±5 %
- Polarity of the output voltage: Positive and negative
- Holding time: At least 5 s
The generator must produce a current waveform that meets the precise parameters detailed in the table below.
Table 3 – Waveshape of the discharge current
| Class | Indicated voltage (kV) | First peak current of discharge (A) (±10%) | Rise time with discharge switch (ns) | Current at 30 ns (A) (±30%) | Current at 60 ns (A) (±30%) |
| 1 | 2 | 7.5 | 0.7 to 1 | 4 | 2 |
| 2 | 4 | 15.0 | 0.7 to 1 | 8 | 4 |
| 3 | 6 | 22.5 | 0.7 to 1 | 12 | 6 |
| 4 | 8 | 30.0 | 0.7 to 1 | 16 | 8 |
The proper use of this specified generator requires a carefully controlled physical environment and test set-up.