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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, multipoint, I/O bus applications.A compact 20-pin surface mount
PLCC or SOIC package provides high transceiver integration and a very small PC board footprint.
Propagation delay skew between devices is specified to aid
in parallel interface designs— limits on maximum and minimum delay times are guaranteed.
Five devices can implement a complete SCSI initiator or target 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 Transceiver
© 1999 National Semiconductor Corporation DS011014 www.national.com
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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
@
+25˚C
V Package 1.73W
M Package 1.73W
Derate V Package 13.9 mW/˚C above +25˚C
Derate M Package 13.7 mW/˚C above +25˚C
Storage Temperature Range −65˚C to +150˚C
Lead Temperature
(Soldering 4 Sec.) 260˚C
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
=
100Ω (EIA-422) 2.0 2.25 V
Voltage (Termination Load) R
L
=
54Ω (EIA-485) 1.5 2.0 V
∆IVODI Change in Magnitude of Driver R
L
=
54 or 100Ω
Differential Output Voltage for (Note 4)
(Figure 1 )
0.2 V
Complementary Output States (EIA-422/485)
V
OC
Driver Common Mode R
L
=
54Ω
(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 µA
I
IL
Input Low Current V
IN
=
0.4V (Note 3) −20 µA
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 µA
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,IO
=
−0.4 mA 0.03 0.2 V
Threshold Voltage (EIA-422/485)
V
TL
Differential Input Low V
O
=
V
OL,IO
=
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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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
=
+25˚C
I
IH
Enable Input V
IN
=
2.4V V
CC
=
3.0V 1 40 µA
Current High DE/RE
V
CC
=
4.75V 1 µA
V
CC
=
5.25V 1 40 µA
V
IN
=
2.4V V
CC
=
3.0V 1 20 µA
DE4 or RE4
V
CC
=
5.25V 1 20 µA
I
IL
Enable Input V
IN
=
0.8V V
CC
=
3.0V −6 −40 µA
Current Low DE/RE
V
CC
=
4.75V −12 µA
V
CC
=
5.25V −14 −40 µA
V
IN
=
0.8V V
CC
=
3.0V −3 −20 µA
DE4 or RE4
V
CC
=
5.25V −7 −20 µA
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
=
110Ω (
Figure 5
)3540ns
t
PZL
Output Enable Time to Low Level (
Figure 6
)2540ns
t
PHZ
Output Disable Time to High Level (
Figure 5
)1525ns
t
PLZ
Output Disable Time to Low Level (
Figure 6
)3540ns
DRIVER DIFFERENTIAL CHARACTERISTICS
t
r,tf
Rise and Fall Time R
L
=
54Ω 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−tPHLD
| Diff. Skew (
Figures 3, 4, 9
)36ns
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−tPHLD
| Diff. Receiver Skew (
Figure 7
)13ns
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
)2030ns
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 isdefinedaspositive.Currentoutof device pins is defined as negative.Allvoltagesarereferencedto ground unless otherwise specified.
Note 3: I
IH
and IILinclude driver input current and receiver TRI-STATE leakage current on DR(1–3).
Note 4: ∆ IVODI and ∆ IVOCI are changes in magnitude of V
OD
and VOC, respectively, that occur when the input changes state.
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Switching Characteristics (Continued)
Note 5: In EIA Standards EIA-422 and EIA-485, VOC, which is the average of the two output voltages with respect to ground, is called output offset voltage, VOS.
Note 6: Threshold parameter limits specified as an algebraic value rather than by magnitude.
Note 7: Hysteresis defined as V
HST
=
V
TH−VTL
.
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
=
+25˚C.
Parameter Measurement Information
DS011014-3
FIGURE 1. Driver VODand VOC(Note 13)
DS011014-4
FIGURE 2. Receiver VOHand 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,tPHZ
)
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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,tPLZ
)
DS011014-11
DS011014-12
FIGURE 7. Receiver Differential Propagation Delay Timing
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Parameter Measurement Information (Continued)
Note 12: The input pulse is supplied by a generator having the following characteristics: f=1.0 MHz, 50%duty cycle, trand t
f
<
6.0 ns, Z
O
=
50Ω.
Note 13: C
L
includes probe and stray capacitance.
Note 14: Diodes are 1N916 or equivalent.
Note 15: Differential propagation delays are calculated from single-ended propagation delays measured from driver input to the 20%and 80%levels on the driver
outputs (
Figure 9
).
DS011014-13
DS011014-14
S1 1.5V
S2 Open
S3 Closed
DS011014-15
S1 −1.5V
S2 Closed
C3 Open
DS011014-16
S1 1.5V
S2 Closed
C3 Closed
DS011014-17
S1 −1.5V
S2 Closed
C3 Closed
FIGURE 8. Receiver Enable and Disable Timing
DS011014-18
Tra,Trb,Tfaand Tfbare propagation delay measurements to the 20%and 80%levels.
T
CP
=
Crossing Point
FIGURE 9. Propagation Delay Timing for Calculations of Driver Differential Propagation Delays
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Parameter Measurement Information (Continued)
Note 16: On transceivers 1–3 the driver is loaded with receiver input conditions when DE/RE is high. Do not exceed the package power dissipation limit when
testing.
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8
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Physical Dimensions inches (millimeters) unless otherwise noted
Order Number DS36954M
NS Package Number M20B
Order Number DS36954V
NS Package Number V20A
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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 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.
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Tel: 1-800-272-9959
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Email: support@nsc.com
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Tel: 81-3-5639-7560
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DS36954 Quad Differential Bus Transceiver
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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