Low-Cost, 230MHz, Single/Quad Op Amps with

Rail-to-Rail Outputs and ±15kV ESD Protection

10

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ESD Protection

As with all Maxim devices, ESD protection structures

are incorporated on all pins to protect against ESD

encountered during handling and assembly. Input and

output pins of the MAX4385E/MAX4386E have extra

protection against static electricity. Maxim’s engineers

have developed state-of-the-art structures enabling

these pins to withstand ESD up to ±15kV without dam-

age when placed in the test circuit (Figure 6). The

MAX4385E/MAX4386E are characterized for protection

to the following limits:

• ±15kV using the Human Body Model

• ±8kV using the Contact Discharge method specified

in IEC 1000-4-2

• ±15kV using the Air-Gap Discharge method speci-

fied in IEC 1000-4-2

Human Body Model

Figure 7 shows the Human Body Model, and Figure 8

shows the current waveform it generates when dis-

charged into a low impedance. This model consists of a

150pF capacitor charged to the ESD voltage of interest,

and then discharged into the test device through a

1.5k

Ω resistor.

IEC 1000-4-2

The IEC 1000-4-2 standard covers ESD testing and

performance of finished equipment; it does not specifi-

cally refer to ICs. The MAX4385E/MAX4386E enable the

design of equipment that meets the highest level (Level

4) of IEC 1000-4-2 without the need for additional ESD

protection components. The major difference between

tests done using the Human Body Model and IEC 1000-

4-2 is higher peak current in IEC 1000-4-2. Because

series resistance is lower in the IEC 1000-4-2 model,

the ESD-withstand voltage measured to this standard is

generally lower than that measured using the Human

Body. Figure 10 shows the IEC 1000-4-2 model and

Figure 9 shows the current waveform for the ±8kV IEC

1000-4-2 Level 4 ESD Contact Discharge test. The Air-

Gap test involves approaching the device with a

charged probe. The Contact Discharge method con-

nects the probe to the device before the probe is ener-

gized.

HIGH-

VOLTAGE

DC

SOURCE

CHARGE CURRENT

LIMIT RESISTOR

DISCHARGE

RESISTANCE

STORAGE

CAPACITOR

Ω

Ω

DEVICE

UNDER

TEST

Figure 7. Human Body ESD Model

90%

36.8%

TIME

CURRENT WAVEFORM

PEAK-TO-PEAK RINGING

(NOT DRAWN TO SCALE)

Ir

10%

0

0

AMPERES

Figure 8. Human Body Current Waveform

220

Ω

220

Ω

75

Ω

MAX438_E

5V

2.2

µF

75

Ω

TEST

POINT B

TEST

POINT A

Figure 6. ESD Test Circuit