MACHINE MODEL

The Machine Model is the standard ESD test method in

Japan and the automotive industry. It simulates a charge on

large object discharging through the IC device. This takes

place in automated test and handling systems. The equip-

ment can accumulate static charge due to improper ground-

ing, which is transmitted through the IC when it is picked and

placed.

The waveform is obtained by discharging 400V volts capaci-

tor to the device. Resistor, R2 = 0

Ω.

The parasitic inductance, L, from the PCB affects the peak

current and period of the waveform. For L = 0.5µF, the peak

current is approximately 7A with a period of 60 ns. For L =

2.5µH, the peak current is reduced to 4A with a period of 140

ns.

IEC 1000-4-2 (EN61000-4-2)

The European Union requires ESD immunity testing for all

electronic products as a condition for EMC Mark before

shipping to any member countries. This is not a IC require-

ment but an overall system requirement. IEC 1000-4-2

specifies ESD testing both by contact and air-gap discharge.

ESD testing by contact are generally more repeatable than

air-gap but is less realistic to actual ESD event. However,

air-gap discharge is more realistic but ESD results may vary

widely dependent on environmental conditions (temperature,

humidity,....) The waveform is obtained by discharging

150pF capacitor through a resistor, R2 = 330

Ω. A typical

peak current may be high as 37A with 10kV.

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FIGURE 3. MM ESD Model

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FIGURE 4. MM Waveform

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FIGURE 5. IEC ESD Model

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FIGURE 6. IEC Waveform

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