MAX481E/MAX483E/MAX485E/
MAX487E–MAX491E/MAX1487E
±±15kV ESD-Potected,VElewDRateDLimited,
LowD-oweP,VRED481/RED422VTPansceivePs
__________FunctionVTablesV(MAX4±ꢅE1MAX4±3E1MAX4±5E1MAX4±7E1MAXꢅ4±7E)
Table ꢅ. Transmitting
Table 2. Receiving
INꢁUTꢃ
OUTꢁUTꢃ
INꢁUTꢃ
OUTꢁUT
RE
DE
A-B
RO
RE
DE
DI
Z
Y
0
0
> +0.2k
1
X
1
1
0
1
0
0
0
0
0
< -0.2k
Inputs open
X
0
1
X
0
1
0
0
0
X
X
1
0
High-Z
High-Z
1
High-Z
1
High-Z
High-Z
*
*
*
X = ꢂon't care
X = ꢂon't care
High-Z = High impedance
Shutdown mode for MAX481E/MAX483E/MAX487E
High-Z = High impedance
Shutdown mode for MAX481E/MAX483E/MAX487E
*
*
neers developed state-of-the-art structures to protect
these pins against ESꢂ of 15ꢀk without damage. The
ESꢂ structures withstand high ESꢂ in all states: normal
operation, shutdown, and powered down. After an ESꢂ
event, Maxim’s MAX481E, MAX483E, MAX485E,
MAX487E–MAX491E, and MAX1487E ꢀeep worꢀing
without latchup.
__________ApplicationsVInfoPmation
The MAX481E/MAX483E/MAX485E/MAX487E–MAX491E
and MAX1487E are low-power transceivers for RS-485
and RS-422 communications. These “E” versions of the
MAX481, MAX483, MAX485, MAX487–MAX491, and
MAX1487 provide extra protection against ESꢂ. The
rugged MAX481E, MAX483E, MAX485E, MAX497E–
MAX491E, and MAX1487E are intended for harsh envi-
ronments where high-speed communication is important.
These devices eliminate the need for transient suppres-
sor diodes and the associated high capacitance loading.
The standard ꢁnon-“E”D MAX481, MAX483, MAX485,
MAX487–MAX491, and MAX1487 are recommended for
applications where cost is critical.
ESꢂ protection can be tested in various ways; the
transmitter outputs and receiver inputs of this product
family are characterized for protection to 15ꢀk using
the Human Body Model.
Other ESꢂ test methodologies include IEC10004-2 con-
tact discharge and IEC1000-4-2 air-gap discharge ꢁfor-
merly IEC801-2D.
The MAX481E, MAX485E, MAX490E, MAX491E, and
MAX1487E can transmit and receive at data rates up to
2.5Mbps, while the MAX483E, MAX487E, MAX488E,
and MAX489E are specified for data rates up to
250ꢀbps. The MAX488E–MAX491E are full-duplex
transceivers, while the MAX481E, MAX483E, MAX487E,
and MAX1487E are half-duplex. In addition, driver-
enable ꢁꢂED and receiver-enable ꢁRED pins are included
on the MAX481E, MAX483E, MAX485E, MAX487E,
MAX489E, MAX491E, and MAX1487E. When disabled,
the driver and receiver outputs are high impedance.
EꢃS Test Conꢂitions
ESꢂ performance depends on a variety of conditions.
Contact Maxim for a reliability report that documents
test set-up, test methodology, and test results.
Human Boꢂy Moꢂel
Figure 4 shows the Human Body Model, and Figure 5
shows the current waveform it generates when dis-
charged into a low impedance. This model consists of
a 100pF capacitor charged to the ESꢂ voltage of inter-
est, which is then discharged into the test device
through a 1.5ꢀΩ resistor.
IECꢅ000-4-2
The IEC1000-4-2 standard covers ESꢂ testing and per-
formance of finished equipment; it does not specifically
refer to integrated circuits ꢁFigure 6D.
±±15kV ESV-Potection
As with all Maxim devices, ESꢂ-protection structures
are incorporated on all pins to protect against electro-
static discharges encountered during handling and
assembly. The driver outputs and receiver inputs have
extra protection against static electricity. Maxim’s engi-
Maxim Integrated
9
ROCHESTER [ Rochester Electronics ]
