Datasheet

500 W
16 V
Input
D and RE Input
500 W
9 V
V
CC
Input
R Output
50 kW
50 kW
180 kW
36 kW
V
CC
DE Input
A and B Output
V
CC
V
CC
Input
Output
9 V
9 V
16 V
36 kW
16 V
5 W
16 V
36 kW
B InputA Input
V
CC
16 V
16 V
Input
V
CC
Output
180 kW
36 kW
SN65HVD3082E, SN75HVD3082E
SN65HVD3085E, SH65HVD3088E
SLLS562G –AUGUST 2009–REVISED MAY 2009 www.ti.com
Receiver failsafe is accomplished by offsetting the receiver thresholds so that the “input indeterminate” range
does not include zero volts differential. To comply with the RS-422 and RS-485 standards, the receiver output
must output a High when the differential input V
ID
is more positive than +200 mV, and must output a Low when
the V
ID
is more negative than -200 mV. The receiver parameters which determine the failsafe performance are
V
IT+
and V
IT-
and V
HYS
. As seen in the RECEIVER ELECTRICAL CHARACTERISTICS table, differential signals
more negative than -200 mV will always cause a Low receiver output. Similarly, differential signals more positive
than +200 mV will always cause a High receiver output.
When the differential input signal is close to zero, it will still be above the V
IT+
threshold, and the receiver output
is High. Only when the differential input is more negative than V
IT-
will the receiver output transition to a Low state.
So, the noise immunity of the receiver inputs during a bus fault condition includes the receiver hysteresis value
V
HYS
(the separation between V
IT+
and V
IT-
) as well as the value of V
IT+
.
EQUIVALENT INPUT AND OUTPUT SCHEMATIC DIAGRAMS
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Product Folder Link(s): SN65HVD3082E SN75HVD3082E SN65HVD3085E SH65HVD3088E