lms202eimx National Semiconductor Corporation, lms202eimx Datasheet - Page 6

• Manufacturer Part Number: lms202eimx
• Description: 15kv Esd Rated, 5v Single Supply Tia/eia-232 Dual Transceivers
• Manufacturer: National Semiconductor Corporation

www.national.com
Application Information
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 = 0Ω.
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.
FIGURE 3. MM ESD Model
FIGURE 4. MM Waveform
(Continued)
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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 = 330Ω. A typical
peak current may be high as 37A with 10kV.
FIGURE 5. IEC ESD Model
FIGURE 6. IEC Waveform
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