±15kV ESD-Protected, Low-Voltage, Dual, SPST,

CMOS Analog Switches

turns off when the ESD event is finished and normal

operation may be resumed. Also, keep in mind that the

holding current varies significantly with temperature.

The worst case is at +85°C when the holding currents

drop to 70mA. Since this is a typical number to guaran-

tee turn-off of the SCRs under all conditions, the sources

connected to these terminals should be current limited

to not more than half this value. When the SCR is

latched, the voltage across it is about 3V, depending on

the polarity of the pin current. The supply voltages do

not affect the holding current appreciably. The sources

connected to the COM side of the switches do not need

to be current limited since the switches turn off internally

when the corresponding SCR(s) latches.

Even though most of the ESD current flows to GND

through the SCRs, a small portion of it goes into V+.

Therefore, it is a good idea to bypass the V+ with 0.1µF

capacitors directly to the ground plane.

ESD protection can be tested in various ways. Trans-

mitter outputs and receiver inputs are characterized for

protection to the following:

•

±15kV using the Human Body Model

•

±8kV using the Contact Discharge method speci-

fied in IEC 1000-4-2 (formerly IEC 801-2)

•

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

fied in IEC 1000-4-2 (formerly IEC 801-2).

ESD Test Conditions

Contact Maxim Integrated Products for a reliability

report that documents test setup, methodology, and

results.

Human Body Model

Figure 6 shows the Human Body Model and Figure 7

shows the waveform it generates when discharged into

a low impedance. This model consists of a 100pF

capacitor charged to the ESD voltage of interest, which

can be 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 per-

formance of finished equipment; it does not specifically

refer to integrated circuits. The MAX4575/MAX4576/

MAX4577 enable the design of equipment that meets

Level 4 (the highest level) of IEC 1000-4-2, without addi-

tional 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 ESD test model (Figure 8),

the ESD withstand voltage measured to this standard is

generally lower than that measured using the Human

Body Model. 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.

Chip Information

TRANSISTOR COUNT: 78

PROCESS: CMOS

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