DataSheet26.com

74LS848 PDF даташит

Спецификация 74LS848 изготовлена ​​​​«Motorola Semiconductors» и имеет функцию, называемую «8-INPUT PRIORITY ENCODERS WITH 3-STATE OUTPUTS».

Детали детали

Номер произв 74LS848
Описание 8-INPUT PRIORITY ENCODERS WITH 3-STATE OUTPUTS
Производители Motorola Semiconductors
логотип Motorola Semiconductors логотип 

6 Pages
scroll

No Preview Available !

74LS848 Даташит, Описание, Даташиты
8-INPUT PRIORITY ENCODERS
WITH 3-STATE OUTPUTS
The SN54 / 74LS348 and the SN54 / 74LS848 are eight input priority encod-
ers which provide the 8-line to 3-line function.
The outputs (A0 – A2) and inputs (0 – 7) are active low. The active low input
which has the highest priority (input 7 has the highest) is represented on the
outputs (output A0 is the lowest bit). An example would be if inputs 1, 2 and 4
were low, then a binary 4 would be represented on the outputs.
The GS (Group Signal) output is active low when any of the inputs are low. It
serves to indicate when any of the inputs are active.
A0, A1 and A2 are three-state outputs. This allows for up to 64 line expan-
sion without the need for special external circuitry.
A logical one on the Enable Input (EI) forces A0, A1 ared A2 to the disabled
state and outputs GS and EO to the high state. A high on all data inputs (0 – 7)
together with a low on the EI input disables outputs A0, A1, and A2 and forces
output GS to the high state and output EO to the low state.
Use of the EI input in conjunction with the EO output provides for the capa-
bility of having priority encoding of n input signals.
The LS848 has special internal circuitry providing for a greatly reduced neg-
ative going glitch on the GS (Group Signal) output and on a reduced tendency
for the A0, A1 and A2 outputs to become momentarily enabled. Both of these
occurrences happen when the EI input goes from a logical one to a logical zero
and all data inputs (0 – 7) are held at logical ones. The internal glitch reduction
circuitry does add an additional fan-in of one on all data inputs (compared to
that of the LS348).
OUTPUTS
VCC EO
16 15
GS
14
INPUTS
321
13 12 11
OUTPUT
0 A0
10 9
EO GS
4
56
3
7
21 0
A0
EI A2 A1
1 2 3 4 56 78
4 5 6 7 EI A2 A1 GND
INPUTS
OUTPUTS
SN54/74LS348
SN54/74LS848
8-INPUT PRIORITY ENCODERS
WITH 3-STATE OUTPUTS
LOW POWER SCHOTTKY
16
1
16
1
16
1
J SUFFIX
CERAMIC
CASE 620-09
N SUFFIX
PLASTIC
CASE 648-08
D SUFFIX
SOIC
CASE 751B-03
ORDERING INFORMATION
SN54LSXXXJ
SN74LSXXXN
SN74LSXXXD
Ceramic
Plastic
SOIC
FUNCTION TABLE
INPUTS
OUTPUTS
EI 0 1 2 3 4 5 6 7 A2 A1 A0 GS EO
H XXXXXXXX Z Z Z H H
L HHHHHHHH Z Z Z H L
L XXXXXXXL L L L L H
L XXXXXXLH L L H L H
L XXXXX LHH L H L L H
L XXXX LHHH L H H L H
L XXX LHHHH H L L L H
L XX LHHHHH H L H L H
L X LHHHHHH H H L L H
L LHHHHHHH H H H L H
FAST AND LS TTL DATA
5-499
H = HIGH Logic Level
L = LOW Logic Level
X = Irrelevant
Z = High Impedance State









No Preview Available !

74LS848 Даташит, Описание, Даташиты
SN54/74LS348 SN54/74LS848
(5)
EI
(10)
0
(11)
1
(12)
2
(13)
3
(1)
4
(2)
5
(3)
6
(4)
7
SN54 / 74LS348
BLOCK DIAGRAMS
(15)
EO
(14)
GS
(9)
A0
(7)
A1
(6)
A2
(5)
EI
(10)
0
G1
(11)
1
(12)
2
(13)
3
(1)
4
(2)
5
(3)
6
(4)
7
G2
G31
G3
G9
G4
G5′ ′G10
G6′ ′G11
G7′ ′G12
G8
G13
G14
G15
G16
G17
G19
G20
G21
G22
G24
G25
G26
G27
SN54 / 74LS848
G29
G30
(15)
EO
(14)
GS
G18
(9)
A0
G23
(7)
A1
G28
(6)
A2
GUARANTEED OPERATING RANGES
Symbol
Parameter
VCC
Supply Voltage
TA Operating Ambient Temperature Range
IOH
Output Current — High
EO, GS
IOH
Output Current — High
A0, A1, A2
A0, A1, A2
IOL
Output Current — Low
EO, GS
IOL
Output Current — Low
A0, A1, A2
A0, A1, A2
Min Typ Max Unit
54 4.5 5.0 5.5
74 4.75 5.0 5.25
V
54 – 55 25 125 °C
74 0 25 70
54, 74
– 0.4
mA
54
– 1.0
mA
74 – 2.6
54 4.0 mA
74 8.0
54 12 mA
74 24
FAST AND LS TTL DATA
5-500









No Preview Available !

74LS848 Даташит, Описание, Даташиты
SN54/74LS348 SN54/74LS848
DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE (unless otherwise specified)
Limits
Symbol
Parameter
Min Typ Max Unit
Test Conditions
VIH Input HIGH Voltage
2.0
V
Guaranteed Input HIGH Voltage for
All Inputs
54
VIL Input LOW Voltage
74
0.7 Guaranteed Input LOW Voltage for
0.8 V All Inputs
VIK
VOH
Input Clamp Diode Voltage
– 0.65 – 1.5 V VCC = MIN, IIN = – 18 mA
Output HIGH Voltage
A0, A1, A2
EO, GS
54, 74
54
2.4
2.5
3.1
3.5
V
VCC = MIN, IOH = MAX, VIN = VIH
V or VIL per Truth Table
EO, GS
74 2.7 3.5
V
VOL
Output LOW Voltage
EO, GS
54, 74
74
0.25 0.4
0.35 0.5
V IOL = 4.0 mA VCC = VCC MIN,
VIN = VIL or VIH
V IOL = 8.0 mA per Truth Table
VOL
Output LOW Voltage
A0, A1, A2
54, 74
74
0.25 0.4
0.35 0.5
V IOL = 12 mA
V IOL = 24 mA
VCC = VCC MIN,
VIN = VIL or VIH
per Truth Table
IOZH
IOZL
Output Off Current HIGH
Output Off Current LOW
Input HIGH Current
Input 0, EI — LS348
20 µA VCC = MAX, VOUT = 2.7 V
–20 µA VCC = MAX, VOUT = 0.4 V
20 µA
Input 0 — LS848
Other — LS348
Other — LS848
IIH
Input HIGH Current
Input 0, EI — LS348
40 µA VCC = MAX, VIN = 2.7 V
40 µA
60 µA
0.1 mA
Input 0 — LS848
Other — LS348
Other — LS848
0.2 mA VCC = MAX, VIN = 7.0 V
0.2 mA
0.3 mA
Input LOW Current
Input 0, EI — LS348
– 0.4 mA
IIL Input 0 — LS848
Other — LS348
Other — LS848
– 0.8
– 0.8
– 1.2
mA VCC = MAX, VIN = 0.4 V
mA
mA
Short Circuit Current (Note 1)
IOS
EO, GS
– 20
A0, A1, A2
– 30
– 120 mA VCC = MAX
– 130 mA
Power Supply Current
Total, Output HIGH
ICC
Total, Output LOW
VCC = MAX
12 23
All Inputs and Outputs Open
mA
13 25
VCC = MAX, Inputs 7, EI = GND
All Others Open
Note 1: Not more than one output should be shorted at a time, nor for more than 1 second.
FAST AND LS TTL DATA
5-501










Скачать PDF:

[ 74LS848.PDF Даташит ]

Номер в каталогеОписаниеПроизводители
74LS8488-INPUT PRIORITY ENCODERS WITH 3-STATE OUTPUTSMotorola Semiconductors
Motorola Semiconductors

Номер в каталоге Описание Производители
TL431

100 мА, регулируемый прецизионный шунтирующий регулятор

Unisonic Technologies
Unisonic Technologies
IRF840

8 А, 500 В, N-канальный МОП-транзистор

Vishay
Vishay
LM317

Линейный стабилизатор напряжения, 1,5 А

STMicroelectronics
STMicroelectronics

DataSheet26.com    |    2020    |

  Контакты    |    Поиск