DS8641
Quad Unified Bus Transceiver
General Description
The DS8641 is a quad high speed drivers/receivers de-
signed for use in bus organized data transmission systems
interconnected by terminated 120
impedance lines. The
external termination is intended to be a 180
resistor from
the bus to the +5V logic supply together with a 390
resistor
from the bus to ground. The bus can be terminated at one or
both ends. Low bus pin current allows up to 27 driver/
receiver pairs to utilize a common bus. The bus loading is
unchanged when V
CC
= 0V. The receivers incorporate tight
thresholds for better bus noise immunity. One two-input NOR
gate is included to disable all drivers in a package simulta-
neously.
Features
n
4 separate driver/receiver pairs per package
n
Guaranteed minimum bus noise immunity of 0.6V, 1.1V
typ
n
Temperature insensitive receiver thresholds track bus
logic levels
n
30 A typical bus terminal current with normal V
CC
or
with V
CC
= 0V
n
Open collector driver output allows wire-OR connection
n
High speed
n
Series 74 TTL compatible driver and disable inputs and
receiver outputs
Connection Diagram
Dual-In-Line Package
DS005806-1
Top View
Order Number DS8641N
See NS Package Number N16A
January 1996
DS8641
Quad
Unified
Bus
T
ransceiver
1999 National Semiconductor Corporation
DS005806
www.national.com
Typical Application
DS005806-2
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2
Absolute Maximum Ratings
(Note 2)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage
7V
Input and Output Voltage
5.5V
Storage Temperature Range
-65C to +150C
Maximum Power Dissipation (Note 1) at 25C
Cavity Package
1433 mW
Molded Package
1362 mW
Lead Temperature (Soldering, 4 seconds)
260C
Operating Conditions
Min
Max
Units
Supply Voltage, (V
CC
)
DS8641
4.75
5.25
V
Temperature Range, (T
A
)
DS8641
0
+70
C
Note 1: Derate molded package 10.9 mW/C above 25C.
Electrical Characteristics
The following apply for V
MIN
V
CC
V
MAX
, T
MIN
T
A
T
MAX
unless otherwise specified (Note 3) and (Note 4)
Symbol
Parameter
Conditions
Min
Typ
Max
Units
DRIVER AND DISABLE INPUTS
V
IH
Logical "1" Input Voltage
2.0
V
V
IL
Logical "0" Input Voltage
0.8
V
I
I
Logical "1" Input Current
V
IN
= 5.5V
1
mA
I
IH
Logical "1" Input Current
V
IN
= 2.4V
40
A
I
IL
Logical "0" Input Current
V
IN
= 0.4V
-1.6
mA
V
CL
Input Diode Clamp Voltage
I
DIS
= -12 mA, I
IN
= -12 mA, I
BUS
= -12 mA,
-1
-1.5
V
T
A
= 25C
DRIVER OUTPUT/RECEIVER INPUT
V
OLB
Low Level Bus Voltage
V
DIS
= 0.8V, V
IN
= 2V, I
BUS
= 50 mA
0.4
0.7
V
I
IHB
Maximum Bus Current
V
IN
= 0.8V, V
BUS
= 4V, V
CC
= V
MAX
30
100
A
I
ILB
Maximum Bus Current
V
IN
= 0.8V, V
BUS
= 4V, V
CC
= 0V
2
100
A
V
IH
High Level Receiver Threshold
V
IND
= 0.8V, V
OL
= 16 mA
1.70
1.50
V
V
IL
Low Level Receiver Threshold
V
IND
= 0.8V, V
OH
= -400 A
1.50
1.30
V
RECEIVER OUTPUT
V
OH
Logical "1" Output Voltage
V
IN
= 0.8V, V
BUS
= 0.5V, I
OH
= -400 A
2.4
V
V
OL
Logical "0" Output Voltage
V
IN
= 0.8V, V
BUS
= 4V, I
OL
= 16 mA
0.25
0.4
V
I
OS
Output Short Circuit Current
V
DIS
= 0.8V, V
IN
= 0.8V, V
BUS
= 0.5V, V
OS
= 0V,
-18
-55
mA
V
CC
= V
MAX
, (Note 5)
I
CC
Supply Current
V
DIS
= 0V, V
IN
= 2V, (per Package)
50
70
mA
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3
Switching Characteristics
T
A
= 25C, V
CC
= 5V, unless otherwise indicated
Symbol
Parameter
Conditions
Min
Typ
Max
Units
t
PD
Propagation Delays (Note 8)
(Note 6)
Disable to Bus "1"
19
30
ns
Disable to Bus "0"
15
30
ns
Driver Input to Bus "1"
17
25
ns
Driver Input to Bus "0"
17
25
ns
Bus to Logical "1" Receiver Output
(Note 7)
20
30
ns
Bus to Logical "0" Receiver Output
18
30
ns
Note 2: "Absolute Maximum Ratings" are those values beyond which the safety of the device cannot be guaranteed. They are not meant to imply that the devices
should be operated at these limits. The table of "Electrical Characteristics" provides conditions for actual device operation.
Note 3: Unless otherwise specified min/max limits apply across the 0C to +70C range for the DS8641. All typical values are for T
A
= 25C and V
CC
= 5V.
Note 4: All currents into device pins shown as positive, out of device pins as negative, all voltages referenced to ground unless otherwise noted. All values shown
as max or min on absolute value basis.
Note 5: Only one output at a time should be shorted.
Note 6: 91
from bus pin to V
CC
and 200
from bus pin to ground. C
LOAD
= 15 pF total. Measured from V
IN
= 1.5V to V
BUS
= 1.5V, V
IN
= 0V to 3V pulse.
Note 7: Fan-out of 10 load, C
LOAD
= 15 pF total. Measured from V
IN
= 1.5V to V
OUT
= 1.5V, V
IN
= 0V to 3V pulse.
Note 8: The following apply for V
CC
= 5V, T
A
= 25C unless otherwise specified.
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4
Physical Dimensions
inches (millimeters) unless otherwise noted
LIFE SUPPORT POLICY
NATIONAL'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL
COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein:
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systems which, (a) are intended for surgical implant
into the body, or (b) support or sustain life, and
whose failure to perform when properly used in
accordance with instructions for use provided in the
labeling, can be reasonably expected to result in a
significant injury to the user.
2. A critical component is any component of a life
support device or system whose failure to perform
can be reasonably expected to cause the failure of
the life support device or system, or to affect its
safety or effectiveness.
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www.national.com
Molded Dual-In-Line Package (N)
Order Number DS8641N
NS Package Number N16A
DS8641
Quad
Unified
Bus
T
ransceiver
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.
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