NSC DM74LS395 4-bit shift register with tri-state output Datasheet

DM74LS395
4-Bit Shift Register with TRI-STATEÉ Outputs
General Description
Features
The LS395 is a 4-bit shift register with TRI-STATE outputs
and can operate in either a synchronous parallel load or a
serial shift-right mode, as determined by the Select input. An
asynchronous active LOW Master Reset (MR) input overrides the synchronous operations and clears the register.
An active LOW Output Enable (OE) input controls the TRISTATE output buffers, but does not interfere with the other
operations. The fourth stage also has a conventional output
for linking purposes in multi-stage serial operations.
Y
Connection Diagram
Logic Symbol
Shift right or parallel 4-bit register
TRI-STATE outputs
Input clamp diodes limit high speed termination effects
Fully CMOS and TTL compatible
Y
Y
Y
Dual-In-Line Package
TL/F/9833 – 2
VCC e Pin 16
GND e Pin 8
TL/F/9833 – 1
Order Number DM74LS395WM or DM74LS395N
See NS Package Number M16B or N16E
Mode Select Table
Inputs
Operating Mode
MR CP
@
tn
Outputs
S DS Pn O0
L
H
O1
@
tn a 1
O2
O3
Asynchronous Reset
Shift, SET First Stage
L
H
X X
K L
X
H
X
X
L
L
L
O0n O1n 02n
Shift, RESET First Stage
Parallel Load
H
H
K L
K H
L
X
X L O0n O1n 02n
Pn P0 P1 P2 P3
tn, tn a 1 e Time before and after CP HIGH-to-LOW transition
H e HIGH Voltage Level
L e LOW Voltage Level
X e Immaterial
TRI-STATEÉ is a registered trademark of National Semiconductor Corporation.
C1995 National Semiconductor Corporation
TL/F/9833
RRD-B30M115/Printed in U. S. A.
DM74LS395 4-Bit Shift Register with TRI-STATE Outputs
February 1992
Absolute Maximum Ratings (Note)
Supply Voltage
Note: The ‘‘Absolute Maximum Ratings’’ are those values
beyond which the safety of the device cannot be guaranteed. The device should not be operated at these limits. The
parametric values defined in the ‘‘Electrical Characteristics’’
table are not guaranteed at the absolute maximum ratings.
The ‘‘Recommended Operating Conditions’’ table will define
the conditions for actual device operation.
7V
Input Voltage
Operating Free Air Temperature Range
Storage Temperature Range
7V
0§ C to a 70§ C
b 65§ C to a 150§ C
Recommended Operating Conditions
Symbol
Parameter
Min
Nom
Max
4.75
5
5.25
Units
VCC
Supply Voltage
VIH
High Level Input Voltage
V
VIL
Low Level Input Voltage
IOH
High Level Output Current
IOL
Low Level Output Current
TA
Free Air Operating Temperature
0
ts (H)
ts (L)
Setup Time HIGH or LOW
S, DS or Pn to CP
20
20
ns
th (H)
th (L)
Hold Time HIGH or LOW
S, DS or Pn to CP
5
5
ns
tw (L)
CP Pulse Width LOW
18
ns
tw (L)
MR Pulse Width LOW
20
ns
2
V
0.8
V
b 0.4
mA
8
mA
70
§C
Electrical Characteristics Over recommended operating free air temperature range (unless otherwise noted)
Symbol
Parameter
Conditions
VI
Input Clamp Voltage
VOH
High Level Output
Voltage
VCC e Min, II e b18 mA
VCC e Min, IOH e Max
VIL e Max
VOL
Low Level Output
Voltage
VCC e Min, IOL e Max
VIH e Min
Min
Typ
(Note 1)
Max
Units
b 1.5
V
2.7
IOL e 4 mA, VCC e Min
VCC e Max, VI e 7V
V
0.35
0.5
0.25
0.4
V
II
Input Current @ Max
Input Voltage
IIH
High Level Input Current
VCC e Max, VI e 2.7V
20
mA
IIL
Low Level Input Current
VCC e Max, VI e 0.4V
b 0.4
mA
IOS
Short Circuit Output Current
VCC e Max (Note 2)
b 100
mA
Supply Current with
Outputs OFF
VCC e Max, OE, DS, S e 4.5V
CP e K, Pn e GND
29
mA
Supply Current with
Outputs ON
VCC e Max, DS, S e 4.5V
OE, CP, Pn e GND
25
mA
IOZH
TRI-STATE Output Off
Current HIGH
VCC e VCCH
VOZH e 2.7V
20
mA
IOZL
TRI-STATE Output Off
Current LOW
VCC e VCCH
VOZL e 0.4V
b 20
mA
ICC
0.1
b 20
Note 1: All typicals are at VCC e 5V, TA e 25§ C.
Note 2: Not more than one output should be shorted at a time, and the duration should not exceed one second.
2
mA
Switching Characteristics
VCC e a 5.0V, TA e a 25§ C
Symbol
RL e 2 kX, CL e 15 pF
Parameter
Min
Units
Max
fmax
Maximum Shift Frequency
tPLH
tPHL
Propagation Delay
CP to On
30
35
25
MHz
ns
tPHL
Propagation Delay
MR to On
35
ns
tPZH
tPZL
Output Enable Time
20
20
ns
tPHZ
tPLZ
Output Disable Time
17
23
ns
Functional Description
served. When the S input is LOW, a CP HIGH-LOW transition transfers data in O0 to O1, O1 to O2, and O2 to O3. A
left-shift is accomplished by connecting the outputs back to
the Pn inputs, but offset one place to the left, i.e., O3 to P2,
O2 to P1, and O1 to P0, with P3 acting as the linking input
from another package.
When the OE input is HIGH, the output buffers are disabled
and the O0 – O3 outputs are in a high impedance condition.
The shifting, parallel loading or resetting operations can still
be accomplished, however.
The ‘LS395 contains four D-type edge-triggered flip-flops
and auxiliary gating to select a D input either from a Parallel
(Pn) input or from the preceding stage. When the Select
input is HIGH, the Pn inputs are enabled. A LOW signal in
the S input enables the serial inputs for shift-right operations, as indicated in the Truth Table.
State changes are initiated by HIGH-to-LOW transitions on
the Clock Pulse (CP) input. Signals on the Pn, DS and S
inputs can change when the Clock is in either state, provided that the recommended setup and hold times are ob-
Logic Diagram
TL/F/9833 – 3
3
4
Physical Dimensions inches (millimeters)
16-Lead Wide Small Outline Molded Package (M)
Order Number DM74LS395WM
NS Package Number M16B
5
DM74LS395 4-Bit Shift Register with TRI-STATE Outputs
Physical Dimensions inches (millimeters) (Continued)
16-Lead Molded Dual-In-Line Package (N)
Order Number DM74LS395N
NS Package Number N16E
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