Datasheet

7–180
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER TEST CONDITIONS MIN MAX UNIT
ABT, AHCT V
CC
= 5.5 V, One input at 3.4 V, Other inputs at V
CC
or GND 1.5
I
CC
CBT
Control inputs
V
CC
= 5.5 V, One input at 3.4 V, Other inputs at V
CC
or GND 2.5
mA
I
CBTLV
V
CC
=36V
One in
p
ut at 3 V
Other in
p
uts at V
CC
or GND
750
µA
I
CC
Control inputs
V
CC
=
3
.
6
V
,
One
inp
u
t
at
3
V
,
Other
inp
u
ts
at
V
CC
or
GND
750
µ
A
I
CC
LVT
V
CC
=3Vto36V
One in
p
ut at V
CC
06V
Other in
p
uts at V
CC
or GND
0.2
mA
I
CC
LVC, ALVC, LV
V
CC
=
3
V
to
3
.
6
V
,
One
inp
u
t
at
V
CC
0
.
6
V
,
Other
inp
u
ts
at
V
CC
or
GND
0.5
mA
Refer to the latest TI data sheets for device specifications.
This is the increase in supply current for each input that is at the specified TTL voltage level rather than V
CC
or GND.
Figure 5. Examples of Supply-Current Change of the Input at TTL Level as Specified in Data Sheets
– Supply Current – mA
CC
I
V
I
– Input Voltage – V
80
60
20
0
0 0.5 1 1.5 2 2.5 3
100
140
160
3.5 4 4.5 5
40
120
5.5 6
V
CC
= 5 V
T
A
= 25°C
All 36 Bits Are Driven
From 0 V to 6 V
Figure 6. Supply Current Versus Input Voltage (36 Inputs)
As long as the driver is active in a transmission path or bus, the receivers input is always in a valid state. No input specification
is violated as long as the rise and fall times are within the data-sheet limits. However, when the driver is in a high-impedance
state, the receiver input is no longer at a defined level and tends to float. This situation can worsen when several transceivers
share the same bus. Figure 7 is an example of a typical bus system. When all transceivers are inactive, the bus-line levels are
undefined. When a voltage that is determined by the leakage currents of each component on the bus is reached, the condition
is known as a floating state. The result is a considerable increase in power consumption and a risk of damaging all components
on the bus. Holding the inputs or I/O pins at a valid logic level when they are not being used or when the part driving them
is in the high-impedance state is recommended.
Figure 7. Typical Bidirectional Bus