2-/4-/6-/8-Channel, ±30kV ESD Protectors in µDFN

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5

During an ESD event, the current pulse rises from zero

to peak value in nanoseconds (Figure 3). For example,

in a ±15kV IEC-61000-4-2 Air-Gap Discharge ESD

event, the pulse current rises to approximately 45A in

an additional 450V to the clamp voltage. An inductance

of 10nH represents approximately 0.5in of board trace.

Regardless of the device’s specified diode clamp volt-

age, a poor layout with parasitic inductance significantly

increases the effective clamp voltage at the protected

signal line.

and GND. This bypass capacitor absorbs the charge

transferred by a +14kV (MAX13204E/MAX13206E/

MAX13208E) and ±12kV (MAX13202E) IEC61000-4-2

Contact Discharge ESD event.

caused by a positive ESD strike without changing its

regulated value. In reality, all power supplies have an

effective output impedance on their positive rails. If a

power supply’s effective output impedance is 1

Ω, then

by using V = I

IEC 61000-4-2 ESD event generates a current spike of

×

1

bypassing increases the clamping voltage. A ceramic

chip capacitor mounted as close to the MAX13202E/

best choice for this application. A bypass capacitor

should also be placed as close to the protected device

as possible.

±30kV ESD Protection

ESD protection can be tested in various ways. The

MAX13202E/MAX13204E/MAX13206E/MAX13208E are

characterized for protection to the following limits:

•±15kV using the Human Body Model

•±14kV (MAX13204E/MAX13206E/MAX13208E) and

±12kV (MAX13202E) using the Contact Discharge

method specified in IEC 61000-4-2

•±30kV using the IEC 61000-4-2 Air-Gap Discharge

method

ESD Test Conditions

ESD performance depends on a number of conditions.

Contact Maxim for a reliability report that documents

test setup, methodology, and results.

CHARGE-CURRENT-

LIMIT RESISTOR

DISCHARGE

RESISTANCE

STORAGE

CAPACITOR

Cs

100pF

1M

Ω

1.5k

Ω

HIGH-

VOLTAGE

DC

SOURCE

DEVICE

UNDER

TEST

Figure 4. Human Body ESD Test Model

90%

36.8%

TIME

CURRENT WAVEFORM

PEAK-TO-PEAK RINGING

(NOT DRAWN TO SCALE)

Ir

10%

0

0

AMPERES

Figure 5. Human Body Model Current Waveform

30ns

60ns

t

100%

90%

10%

I

Figure 3. IEC 61000-4-2 ESD Generator Current Waveform