SN54LS155J [ONSEMI]
DUAL 1-OF-4 DECODER/ DEMULTIPLEXER; 1 -OF- 4双解码器/解复用器
| 型号： | SN54LS155J |
| 厂家： | 
ONSEMI |
| 描述： | DUAL 1-OF-4 DECODER/ DEMULTIPLEXER |
| 文件： | 总4页 (文件大小：82K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
SN54/74LS155
SN54/74LS156
DUAL 1-OF-4 DECODER/
DEMULTIPLEXER
The SN54/74LS155 and SN54/74LS156 are high speed Dual 1-of-4
Decoder/Demultiplexers. These devices have two decoders with common
2-bit Address inputs and separate gated Enable inputs. Decoder “a” has an
Enable gate with one active HIGH and one active LOW input. Decoder “b” has
two active LOW Enable inputs. If the Enable functions are satisfied, one
output of each decoder will be LOW as selected by the address inputs. The
LS156 has open collector outputs for wired-OR (DOT-AND) decoding and
function generator applications.
DUAL 1-OF-4 DECODER/
DEMULTIPLEXER
LS156-OPEN-COLLECTOR
LOW POWER SCHOTTKY
The LS155 and LS156 are fabricated with the Schottky barrier diode
process for high speed and are completely compatible with all Motorola TTL
families.
• Schottky Process for High Speed
• Multifunction Capability
J SUFFIX
CERAMIC
CASE 620-09
• Common Address Inputs
16
• True or Complement Data Demultiplexing
• Input Clamp Diodes Limit High Speed Termination Effects
• ESD > 3500 Volts
1
N SUFFIX
PLASTIC
CASE 648-08
16
CONNECTION DIAGRAM DIP (TOP VIEW)
1
V
E
E
A
O
O
O
O
0b
CC
16
b
b
0
3b
12
2b
11
1b
10
15
14
13
9
D SUFFIX
SOIC
CASE 751B-03
NOTE:
The Flatpak version
has the same pinouts
(Connection Diagram) as
the Dual In-Line Package.
16
1
ORDERING INFORMATION
1
2
3
4
5
6
8
7
SN54LSXXXJ Ceramic
SN74LSXXXN Plastic
SN74LSXXXD SOIC
E
E
A
O
O
O
O
0a
GND
a
a
1
3a
2a
1a
LOGIC SYMBOL
PIN NAMES
LOADING (Note a)
1
2
13 3
14 15
HIGH
LOW
A , A
Address Inputs
Enable (Active LOW) Inputs
Enable (Active HIGH) Input
0.5 U.L.
0.5 U.L.
0.5 U.L.
10 U.L.
0.25 U.L.
0.25 U.L.
0.25 U.L.
0
1
b
E , E
a
a
E
E
E
O –O
Active LOW Outputs (Note b)
5 (2.5) U.L.
A
A
A
A
0
3
0
0
DECODER a
DECODER b
NOTES:
1
1
a) 1 TTL Unit Load (U.L.) = 40 µA HIGH/1.6 mA LOW.
0
1
2
3
0
1
2
3
b) The Output LOW drive factor is 2.5 U.L. for Military (54) and 5 U.L. for Commercial (74)
Temperature Ranges. The HIGH level drive for the LS156 must be established by an external
resistor.
7
6
5
4
9
10 11 12
V
= PIN 16
CC
GND = PIN 8
FAST AND LS TTL DATA
5-1
SN54/74LS155 • SN54/74LS156
LOGIC DIAGRAM
E
E
A
A
E E
b b
a
a
2
0
1
1
13
3
14
15
V
= PIN 16
CC
GND = PIN 8
7
6
5
4
9
10
11
12
= PIN NUMBERS
O
O
O
O
O
O
O
O
3b
0a
1a
2a
3a
0b
1b
2b
FUNCTIONAL DESCRIPTION
The LS155 and LS156 are Dual 1-of-4 Decoder/Demulti-
plexers with common Address inputs and separate gated
Enable inputs. When enabled, each decoder section accepts
AND the minterm functions by tying outputs together. Any
number of terms can be wired-AND as shown below.
f = (E + A + A ) (E + A + A ) (E + A + A )
0
1
0
1
0
1
the binary weighted Address inputs (A , A ) and provides four
0
1
(E + A + A )
0
1
mutuallyexclusiveactiveLOWoutputs(O –O ).IftheEnable
0
3
requirements of each decoder are not met, all outputs of that
decoder are HIGH.
where E = E + E ; E = E + E
a a b
b
E
E
Each decoder section has a 2-input enable gate. The
enable gate for Decoder “a” requires one active HIGH input
A
A
A
A
O
0
1
0
1
O
O
O
0
1
2
3
0
1
2
and one active LOW input (E •E ). In demultiplexing applica-
a
a
E
E
tions, Decoder “a” can accept either true or complemented
databyusingtheE orE inputsrespectively.Theenablegate
A
A
A
A
O
O
O
0
1
0
1
a
a
for Decoder “b” requires two active LOW inputs (E •E ). The
b
b
E
E
LS155 or LS156 can be used as a 1-of-8 Decoder/Demulti-
plexerbytyingE toE andrelabelingthecommonconnection
A
A
A
A
0
1
0
1
a
b
as (A ). The other E and E are connected together to form
2
b
a
E
E
the common enable.
A
A
O
0
1
0
1
3
The LS155 and LS156 can be used to generate all four
minterms of two variables. These four minterms are useful in
some applications replacing multiple gate functions as shown
in Fig. a. The LS156 has the further advantage of being able to
A
A
Figure a
TRUTH TABLE
ADDRESS
ENABLE “a”
OUTPUT “a”
ENABLE “b”
OUTPUT “b”
A
A
E
a
E
a
O
O
O
O
E
b
E
b
O
O
O
O
3
0
1
0
1
2
3
0
1
2
X
X
L
X
H
H
H
H
H
X
H
H
H
H
X
L
H
L
X
L
L
H
H
X
H
H
H
H
H
L
L
L
L
H
L
H
H
H
H
H
L
H
H
H
H
H
L
H
H
H
H
L
X
L
L
L
L
H
L
L
L
L
H
L
H
H
H
H
H
L
H
H
H
H
H
L
H
H
H
H
L
H
H
H
H = HIGH Voltage Level
L = LOW Voltage Level
X = Don’t Care
FAST AND LS TTL DATA
5-2
SN54/74LS155
GUARANTEED OPERATING RANGES
Symbol
Parameter
Min
Typ
Max
Unit
V
CC
Supply Voltage
54
74
4.5
4.75
5.0
5.0
5.5
5.25
V
T
A
Operating Ambient Temperature Range
54
74
–55
0
25
25
125
70
°C
I
I
Output Current — High
Output Current — Low
54, 74
–0.4
mA
mA
OH
54
74
4.0
8.0
OL
DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE (unless otherwise specified)
Limits
Symbol
Parameter
Input HIGH Voltage
Unit
Test Conditions
Min
Typ
Max
Guaranteed Input HIGH Voltage for
All Inputs
V
2.0
V
IH
54
74
0.7
0.8
Guaranteed Input LOW Voltage for
All Inputs
V
V
V
Input LOW Voltage
V
IL
Input Clamp Diode Voltage
Output HIGH Voltage
–0.65
3.5
–1.5
V
V
V
V
V
= MIN, I = –18 mA
IN
IK
CC
54
74
2.5
2.7
= MIN, I
= MAX, V = V
IN
CC
OH
IH
OH
or V per Truth Table
IL
3.5
V
V
= V
= V or V
IL
MIN,
CC
54, 74
74
0.25
0.35
0.4
0.5
V
V
I
I
= 4.0 mA
= 8.0 mA
CC
IN
OL
V
Output LOW Voltage
Input HIGH Current
IH
OL
per Truth Table
OL
20
0.1
µA
mA
mA
mA
mA
V
V
V
V
V
= MAX, V = 2.7 V
IN
CC
CC
CC
CC
CC
I
IH
= MAX, V = 7.0 V
IN
I
I
I
Input LOW Current
–0.4
–100
10
= MAX, V = 0.4 V
IN
IL
Short Circuit Current (Note 1)
Power Supply Current
–20
= MAX
= MAX
OS
CC
Note 1: Not more than one output should be shorted at a time, nor for more than 1 second.
AC CHARACTERISTICS (T = 25°C)
A
Limits
Typ
Symbol
Parameter
Propagation Delay
Unit
Test Conditions
Min
Max
t
t
10
19
15
30
PLH
PHL
ns
Figure 1
Figure 2
Figure 1
Address, E or E to Output
a
b
t
t
Propagation Delay
Address to Output
17
19
26
30
V
= 5.0 V
PLH
PHL
CC
= 15 pF
ns
ns
C
L
t
t
Propagation Delay
18
18
27
27
PLH
PHL
E
a
to Output
AC WAVEFORMS
1.3 V
1.3 V
V
1.3 V
t
1.3 V
V
IN
IN
t
t
t
PHL
PLH
PHL
PLH
1.3 V
1.3 V
V
1.3 V
1.3 V
V
OUT
OUT
Figure 1
Figure 2
FAST AND LS TTL DATA
5-3
SN54/74LS156
GUARANTEED OPERATING RANGES
Symbol
Parameter
Min
Typ
Max
Unit
V
CC
Supply Voltage
54
74
4.5
4.75
5.0
5.0
5.5
5.25
V
T
A
Operating Ambient Temperature Range
54
74
–55
0
25
25
125
70
°C
V
Output Voltage — High
Output Current — Low
54, 74
5.5
V
OH
I
54
74
4.0
8.0
mA
OL
DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE (unless otherwise specified)
Limits
Symbol
Parameter
Input HIGH Voltage
Unit
Test Conditions
Min
Typ
Max
Guaranteed Input HIGH Voltage for
All Inputs
V
2.0
V
IH
54
74
0.7
0.8
Guaranteed Input LOW Voltage for
All Inputs
V
V
Input LOW Voltage
V
IL
Input Clamp Diode Voltage
Output HIGH Current
–0.65
–1.5
100
V
V
V
= MIN, I = –18 mA
IN
IK
CC
I
54, 74
54, 74
µA
= MIN, V
= MAX
OH
OH
CC
V
V
= V
= V or V
MIN,
0.25
0.35
0.4
0.5
V
V
I
= 4.0 mA
= 8.0 mA
CC
IN
CC
IL
OL
V
OL
Output LOW Voltage
Input HIGH Current
IH
74
I
OL
per Truth Table
20
0.1
µA
mA
mA
mA
V
CC
V
CC
V
CC
V
CC
= MAX, V = 2.7 V
IN
I
IH
= MAX, V = 7.0 V
IN
I
I
Input LOW Current
–0.4
10
= MAX, V = 0.4 V
IN
IL
Power Supply Current
= MAX
CC
AC CHARACTERISTICS (T = 25°C)
A
Limits
Typ
Symbol
Parameter
Propagation Delay
Unit
Test Conditions
Min
Max
t
t
25
34
40
51
PLH
PHL
ns
Figure 1
Figure 2
Figure 1
Address, E or E to Output
a
b
V
C
R
= 5.0 V
CC
t
t
Propagation Delay
Address to Output
31
34
46
51
PLH
PHL
ns
ns
= 15 pF
L
= 2.0 kΩ
L
t
t
Propagation Delay
32
32
48
48
PLH
PHL
E
a
to Output
AC WAVEFORMS
1.3 V
1.3 V
V
1.3 V
t
1.3 V
V
IN
IN
t
t
t
PHL
PLH
PHL
PLH
1.3 V
1.3 V
V
1.3 V
1.3 V
V
OUT
OUT
Figure 1
Figure 2
FAST AND LS TTL DATA
5-4
相关型号：
©2020 ICPDF网 联系我们和版权申明