DS36954
Quad Differential Bus Transceiver
General Description
The DS36954 is a low power, quad EIA-485 differential bus
transceiver especially suited for high speed, parallel, multi-
point, I/O bus applications. A compact 20-pin surface mount
PLCC or SOIC package provides high transceiver integra-
tion and a very small PC board footprint.
Propagation delay skew between devices is specified to aid
in parallel interface designs -- limits on maximum and mini-
mum delay times are guaranteed.
Five devices can implement a complete SCSI initiator or tar-
get interface. Three transceivers in a package are pinned out
for data bus connections. The fourth transceiver, with the
flexibility provided by its individual enables, can serve as a
control bus transceiver.
Features
n
Pinout for SCSI interface
n
Compact 20-pin PLCC or SOIC package
n
Meets EIA-485 standard for multipoint bus transmission
n
Greater than 60 mA source/sink currents
n
Thermal shutdown protection
n
Glitch-free driver outputs on power up and down
Connection Diagrams
Logic Diagrams
TRI-STATE
is a registered trademark of National Semiconductor Corporation.
DS011014-1
Order Number DS36954V
See NS Package Number V20A
DS011014-19
Order Number DS36954M
See NS Package Number M20B
DS011014-2
July 1998
DS36954
Quad
Differential
Bus
T
ransceiver
1999 National Semiconductor Corporation
DS011014
www.national.com
Absolute Maximum Ratings
(Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage
7V
Control Input Voltage
V
CC
+ 0.5V
Driver Input Voltage
V
CC
+ 0.5V
Driver Output Voltage/
Receiver Input Voltage
-10V to +15V
Receiver Output Voltage
5.5V
Continuous Power Dissipation
@
+25C
V Package
1.73W
M Package
1.73W
Derate V Package
13.9 mW/C above +25C
Derate M Package
13.7 mW/C above +25C
Storage Temperature Range
-65C to +150C
Lead Temperature
(Soldering 4 Sec.)
260C
Recommended
Operating Conditions
Min
Max
Units
Supply Voltage, V
CC
4.75
5.25
V
Bus Voltage
-7
+12
V
Operating Free Air
Temperature (T
A
)
0
+70
C
Electrical Characteristics
(Note 2)
Over Supply Voltage and Operating Temperature ranges, unless otherwise specified
Symbol
Parameter
Conditions
Min
Typ
Max
Units
DRIVER CHARACTERISTICS
V
ODL
Differential Driver Output
I
L
= 60 mA
1.5
1.9
V
Voltage (Full Load)
V
CM
= 0V
V
OD
Differential Driver Output
R
L
= 100
(EIA-422)
2.0
2.25
V
Voltage (Termination Load)
R
L
= 54
(EIA-485)
1.5
2.0
V
IVODI
Change in Magnitude of Driver
R
L
= 54 or 100
Differential Output Voltage for
(Note 4)
(Figure 1 )
0.2
V
Complementary Output States
(EIA-422/485)
V
OC
Driver Common Mode
R
L
= 54
(Figure 1 ) (EIA-485)
3.0
V
Output Voltage (Note 5)
IVOCI
Change in Magnitude of
(Note 4)
(Figure 1 )
0.2
V
Common Mode Output Voltage
(EIA-422/485)
V
OH
Output Voltage High
I
OH
= -55 mA
2.7
3.2
V
V
OL
Output Voltage Low
I
OL
= 55 mA
1.4
1.7
V
V
IH
Input Voltage High
2.0
V
V
IL
Input Voltage Low
0.8
V
V
CL
Input Clamp Voltage
I
CL
= -18 mA
-1.5
V
I
IH
Input High Current
V
IN
= 2.4V (Note 3)
20
A
I
IL
Input Low Current
V
IN
= 0.4V (Note 3)
-20
A
I
OSC
Driver Short-Circuit
V
O
= -7V (EIA-485)
-130
-250
mA
Output Current
V
O
= 0V (EIA-422)
-90
-150
mA
(Note 9)
V
O
= +12V (EIA-485)
130
250
mA
RECEIVER CHARACTERISTICS
I
OSR
Short Circuit Output Current
V
O
= 0V (Note 9)
-15
-28
-75
mA
I
OZ
TRI-STATE
Output Current
V
O
= 0.4V to 2.4V
20
A
V
OH
Output Voltage High
V
ID
= 0.2V, I
OH
= 0.4 mA
2.4
3.0
V
V
OL
Output Voltage Low
V
ID
= -0.2V, I
OL
= 4 mA
0.35
0.5
V
V
TH
Differential Input High
V
O
= V
OH
, I
O
= -0.4 mA
0.03
0.2
V
Threshold Voltage
(EIA-422/485)
V
TL
Differential Input Low
V
O
= V
OL
, I
O
= 4.0 mA
-0.20
-0.03
V
Threshold Voltage (Note 6)
(EIA-422/485)
V
HST
Hysteresis (Note 7)
V
CM
= 0V
35
60
mV
DRIVER AND RECEIVER CHARACTERISTICS
V
IH
Enable Input Voltage High
2.0
V
V
IL
Enable Input Voltage Low
0.8
V
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2
Electrical Characteristics
(Note 2) (Continued)
Over Supply Voltage and Operating Temperature ranges, unless otherwise specified
Symbol
Parameter
Conditions
Min
Typ
Max
Units
DRIVER AND RECEIVER CHARACTERISTICS
V
CL
Enable Input Clamp Voltage
I
CL
= -18 mA
-1.5
V
I
IN
Line Input Current
Other Input = 0V
V
I
= +12V
0.5
1.0
mA
(Note 8)
DE/RE = 0.8V
V
I
= -7V
-0.45
-0.8
mA
DE4 = 0.8V
I
ING
Line Input Current
Other Input = 0V
V
I
= +12V
1.0
mA
(Note 8)
DE/RE and DE4 = 2V
V
CC
= 3.0V
V
I
= -7V
-0.8
mA
T
A
= +25C
I
IH
Enable Input
V
IN
= 2.4V
V
CC
= 3.0V
1
40
A
Current High
DE/RE
V
CC
= 4.75V
1
A
V
CC
= 5.25V
1
40
A
V
IN
= 2.4V
V
CC
= 3.0V
1
20
A
DE4 or RE4
V
CC
= 5.25V
1
20
A
I
IL
Enable Input
V
IN
= 0.8V
V
CC
= 3.0V
-6
-40
A
Current Low
DE/RE
V
CC
= 4.75V
-12
A
V
CC
= 5.25V
-14
-40
A
V
IN
= 0.8V
V
CC
= 3.0V
-3
-20
A
DE4 or RE4
V
CC
= 5.25V
-7
-20
A
I
CCD
Supply Current (Note 10)
No Load, DE/RE and DE4 = 2.0V
75
90
mA
I
CCR
Supply Current (Note 10)
No Load, DE/RE and RE4 = 0.8V
50
70
mA
Switching Characteristics
Over Supply Voltage and Operating Temperature ranges, unless otherwise specified.
Symbol
Parameter
Conditions
Min
Typ
Max
Units
DRIVER SINGLE-ENDED CHARACTERISTICS
t
PZH
Output Enable Time to High Level
R
L
= 110
(
Figure 5 )
35
40
ns
t
PZL
Output Enable Time to Low Level
(
Figure 6 )
25
40
ns
t
PHZ
Output Disable Time to High Level
(
Figure 5 )
15
25
ns
t
PLZ
Output Disable Time to Low Level
(
Figure 6 )
35
40
ns
DRIVER DIFFERENTIAL CHARACTERISTICS
t
r
, t
f
Rise and Fall Time
R
L
= 54
13
16
ns
t
PLHD
Differential Propagation
C
L
= 50 pF
9
15
19
ns
t
PHLD
Delays (Note 15)
C
D
= 15 pF
9
12
19
ns
t
SKD
|t
PLHD
- t
PHLD
| Diff. Skew
(
Figures 3, 4, 9 )
3
6
ns
RECEIVER CHARACTERISTICS
t
PLHD
Differential Propagation Delays
C
L
= 15 pF
9
14
19
ns
t
PHLD
V
CM
= 2.0V
9
13
19
ns
t
SKD
|t
PLHD
- t
PHLD
| Diff. Receiver Skew
(
Figure 7 )
1
3
ns
t
PZH
Output Enable Time to High Level
C
L
= 15 pF
15
22
ns
t
PZL
Output Enable Time to Low Level
(
Figure 8 )
20
30
ns
t
PHZ
Output Disable Time from High Level
20
30
ns
t
PLZ
Output Disable Time from Low Level
17
25
ns
Note 1: "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 tables of "Electrical Characteristics" specify conditions for device operation.
Note 2: Current into device pins is defined as positive. Current out of device pins is defined as negative. All voltages are referenced to ground unless otherwise speci-
fied.
Note 3: I
IH
and I
IL
include driver input current and receiver TRI-STATE leakage current on DR(13).
Note 4:
IVODI and
IVOCI are changes in magnitude of V
OD
and V
OC
, respectively, that occur when the input changes state.
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3
Switching Characteristics
(Continued)
Note 5: In EIA Standards EIA-422 and EIA-485, V
OC
, which is the average of the two output voltages with respect to ground, is called output offset voltage, V
OS
.
Note 6: Threshold parameter limits specified as an algebraic value rather than by magnitude.
Note 7: Hysteresis defined as V
HST
= V
TH
- V
TL
.
Note 8: I
IN
includes the receiver input current and driver TRI-STATE leakage current.
Note 9: Short one output at a time.
Note 10: Total package supply current.
Note 11: All typicals are given for V
CC
= 5.0V and T
A
= +25C.
Parameter Measurement Information
DS011014-3
FIGURE 1. Driver V
OD
and V
OC
(Note 13)
DS011014-4
FIGURE 2. Receiver V
OH
and V
OL
DS011014-5
FIGURE 3. Driver Differential
Propagation Delay Load Circuit
DS011014-6
FIGURE 4. Driver Differential Propagation
Delays and Transition Times
DS011014-7
S1 to OA for DI = 3V
S1 to OB for DI = 0V
DS011014-8
FIGURE 5. Driver Enable and Disable Timing (t
PZH
, t
PHZ
)
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4
Parameter Measurement Information
(Continued)
DS011014-9
S1 to OA for DI = 0V
S1 to OB for DI = 3V
DS011014-10
FIGURE 6. Driver Enable and Disable Timing (t
PZL
, t
PLZ
)
DS011014-11
DS011014-12
FIGURE 7. Receiver Differential Propagation Delay Timing
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5
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