M
±15kV ESD-Protected, 1μA, 16Mbps, Dual/Quad
Low-Voltage Level Translators in UCSP
______________________________________________________________________________________
13
±15kV ESD Protection
As with all Maxim devices, ESD-protection structures are
incorporated on all pins to protect against electrostatic
discharges encountered during handling and assembly.
The I/O V
CC
lines have extra protection against static
electricity. Maxim
’
s engineers have developed state-of-
the-art structures to protect these pins against ESD of
±15kV without damage. The ESD structures withstand
high ESD in all states: normal operation, three-state out-
put mode, and powered down. After an ESD event,
Maxim
’
s E versions keep working without latchup,
whereas competing products can latch and must be
powered down to remove latchup.
ESD protection can be tested in various ways. The I/O
V
CC
lines of this product family are characterized for
protection to the following limits:
1) ±15kV using the Human Body Model
2) ±8kV using the Contact Discharge method specified
in IEC 1000-4-2
3) ±10kV using IEC 1000-4-2
’
s Air-Gap Discharge
method
ESD Test Conditions
ESD performance depends on a variety of conditions.
Contact Maxim for a reliability report that documents
test setup, test methodology, and test results.
Human Body Model
Figure 3a shows the Human Body Model and Figure 3b
shows the current waveform it generates when dis-
charged into a low impedance. This model consists of
a 100pF capacitor charged to the ESD voltage of inter-
est, which is then discharged into the test device
through a 1.5k
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 integrated circuits. The MAX3372E
–
MAX3379E and MAX3390E
–
MAX3393E help to design
equipment that meets Level 3 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 cur-
rent in IEC 1000-4-2, because series resistance is lower
in the IEC 1000-4-2 model. Hence, the ESD withstand
voltage measured to IEC 1000-4-2 is generally lower than
that measured using the Human Body Model. Figure 4a
shows the IEC 1000-4-2 model, and Figure 4b 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 connects
the probe to the device before the probe is energized.
Machine Model
The Machine Model for ESD tests all pins using a
200pF storage capacitor and zero discharge resis-
tance. Its objective is to emulate the stress caused by
contact that occurs with handling and assembly during
manufacturing. Of course, all pins require this protec-
tion during manufacturing, not just inputs and outputs.
Therefore, after PC board assembly, the Machine
Model is less relevant to I/O ports.
CHARGE-CURRENT-
LIMIT RESISTOR
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
Cs
100pF
R
C
1M
R
D
1500
HIGH-
VOLTAGE
DC
SOURCE
DEVICE
UNDER
TEST
Figure 3a. Human Body ESD Test Model
I
P
100%
90%
36.8%
t
RL
TIME
t
DL
CURRENT WAVEFORM
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
Ir
10%
0
0
AMPERES
Figure 3b. Human Body Current Waveform