DS8838
Quad Unified Bus Transceiver
General Description
The DS8838 is a quad high speed driver/receiver designed
for use in bus organized data transmission systems intercon-
nected by terminated 120
impedance lines. The external
termination is intended to be 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 hysteresis to
greatly enhance bus noise immunity. One two-input NOR
gate is included to disable all drivers in a package simulta-
neously. Receiver performance is optimized for systems with
bus rise and fall times
1.0 s/V.
Features
n
4 totally separate driver/receiver pairs per package
n
1V typical receiver input hysteresis
n
Receiver hysteresis independent of receiver output load
n
Guaranteed minimum bus noise immunity of 1.3V, 2V
typ.
n
Temperature-insensitive receiver thresholds track bus
logic levels
n
20 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
Typical Application
DS005812-1
May 1999
DS8838
Quad
Unified
Bus
Receiver
1999 National Semiconductor Corporation
DS005812
www.national.com
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
Lead Temperature, (Soldering, 4 sec.)
260C
Maximum Power Dissipation (Note 1) at 25C
Cavity Package:
1433 mW
Molded DIP Package:
1362 mW
SO Package:
1002 mW
Operating Conditions
Operating Temperature Range
0C to +70C
Supply Voltage (V
CC
)
4.75V
V
CC
5.25V
Note 1: Derate cavity package 9.6 mW/C above 25C; derate molded DIP
package 10.9 mW/C above 25C; derate SO package 8.01 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 (Notes 3, 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,
T
A
= 25C
-1
-1.5
V
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
20
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, I
OL
= 16 mA, V
CC
=
Max
1.80
2.25
2.50
V
V
IL
Low Level Receiver Threshold
V
IND
= 0.8V, V
OH
= -400 A, V
CC
= Min
1.05
1.30
1.55
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, V
CC
= V
MAX
, (Note 5)
-18
-55
mA
I
CC
Supply Current
V
DIS
= 0V, V
IN
= 2V, (Per Package)
50
70
mA
t
pd
Propagation Delays (Note 9)
Disable to Bus "1"
(Note 6)
19
30
ns
Disable to Bus "0"
(Note 6)
15
23
ns
Driver Input to Bus "1"
(Note 6)
17
25
ns
Driver Input to Bus "0"
(Note 6)
9
15
ns
Bus to Logical "1" Receiver
Output
(Note 7)
20
30
ns
Bus to Logical "0" Receiver
Output
(Note 8)
18
30
ns
Note 2: "Absolute Maximum Ratings" are those values beyond which the safety of the device cannot be guaranteed. Except for "Operating Temperature Range" 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 -55C to +125C temperature range for the DS7838 and across the 0C to +70C range for the
DS8838. 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 3.0V pulse.
Note 7: Fan-out of 10 load, C
LOAD
= 15 pF total. Measured from V
IN
= 1.3V to V
OUT
= 1.5V, V
IN
= 0V to 3.0V pulse.
Note 8: Fan-out of 10 load, C
LOAD
= 15 pF total. Measured from V
IN
= 2.3V to V
OUT
= 1.5V, V
IN
= 0V to 3.0V pulse.
Note 9: These apply for V
CC
= 5V, T
A
= 25C unless otherwise speicified.
www.national.com
3
Notes
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:
1. Life support devices or systems are devices or
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.
National Semiconductor
Corporation
Americas
Tel: 1-800-272-9959
Fax: 1-800-737-7018
Email: support@nsc.com
National Semiconductor
Europe
Fax: +49 (0) 1 80-530 85 86
Email: europe.support@nsc.com
Deutsch Tel: +49 (0) 1 80-530 85 85
English
Tel: +49 (0) 1 80-532 78 32
Franais Tel: +49 (0) 1 80-532 93 58
Italiano
Tel: +49 (0) 1 80-534 16 80
National Semiconductor
Asia Pacific Customer
Response Group
Tel: 65-2544466
Fax: 65-2504466
Email: sea.support@nsc.com
National Semiconductor
Japan Ltd.
Tel: 81-3-5639-7560
Fax: 81-3-5639-7507
www.national.com
DS8838
Quad
Unified
Bus
Receiver
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.
PDF 
ZIP
