54ACT251.pdf 데이터시트 (총 10 페이지) - 파일 다운로드 54ACT251 데이타시트 다운로드

No Preview Available !

www.DataSheet4U.com
August 1998
54AC251 54ACT251
8-Input Multiplexer with TRI-STATE® Output
General Description
The ’AC/’ACT251 is a high-speed 8-input digital multiplexer.
It provides, in one package, the ability to select one bit of
data from up to eight sources. It can be used as universal
function generator to generate any logic function of four vari-
ables. Both true and complementary outputs are provided.
Features
n ICC reduced by 50%
n Multifunctional capability
n On-chip select logic decoding
n Inverting and noninverting TRI-STATE outputs
n Outputs source/sink 24 mA
n ’ACT251 has TTL-compatible inputs
n Standard Military Drawing (SMD)
— ’AC251: 5962-87692
— ’ACT251: 5962-89599
Logic Symbols
IEEE/IEC
DS100284-1
Pin Names
S0– S2
OE
I0– I7
Z
Z
Description
Select Inputs
TRI-STATE Output Enable Input
Multiplexer Inputs
TRI-STATE Multiplexer Output
Complementary TRI-STATE Multiplexer
Output
DS100284-2
TRI-STATE® is a registered trademark of National Semiconductor Corporation.
FACT® is a registered trademark of Fairchild Semiconductor Corporation.
© 1998 National Semiconductor Corporation DS100284
www.national.com

No Preview Available !

Connection Diagrams
Pin Assignment
for DIP and Flatpak
DS100284-3
Pin Assignment
for LCC
DS100284-4
Functional Description
This device is a logical implementation of a single-pole,
8-position switch with the switch position controlled by the
state of three Select inputs, S0, S1, S2. Both true and
complementary outputs are provided. The Output Enable in-
put ( OE) is active LOW. When it is activated, the logic func-
tion provided at the output is:
Z = OE (I0 S0 S1 S2 + I1S0 S1 S 2 +
I2 S0 S 1 S2 + I3 S 0 S1 S2 +
I4 S0 S1 S2 + I5 S 0 S1 S2 +
I6 S0 S 1 S2 + I7 S0 S1 S2)
When the Output Enable is HIGH, both outputs are in the
high impedance (High Z) state. This feature allows multi-
plexer expansion by tying the outputs of up to 128 devices
together. When the outputs of the TRI-STATE devices are
tied together, all but one device must be in the high imped-
ance state to avoid high currents that would exceed the
maximum ratings. The Output Enable signals should be de-
signed to ensure there is no overlap in the active-LOW por-
tion of the enable voltages.
Truth Table
Inputs
OE S2 S1
HXX
LLL
LLL
L LH
L LH
LHL
LHL
L HH
L HH
H = HIGH Voltage Level
L = LOW Voltage Level
X = Immaterial
Z = High Impedance
S0
X
L
H
L
H
L
H
L
H
Outputs
ZZ
ZZ
I0 I0
I1 I1
I2 I2
I3 I3
I4 I4
I5 I5
I6 I6
I7 I7
www.national.com
2

No Preview Available !

Logic Diagram
DS100284-5
Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays.
3 www.national.com

No Preview Available !

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 (VCC)
DC Input Diode Current (IIK)
VI = −0.5V
VI = VCC + 0.5V
DC Input Voltage (VI)
DC Output Diode Current (IOK)
VO = −0.5V
VO = VCC + 0.5V
DC Output Voltage (VO)
DC Output Source
or Sink Current (IO)
DC VCC or Ground Current
per Output Pin (ICC or IGND)
Storage Temperature (TSTG)
Junction Temperature (TJ)
CDIP
−0.5V to +7.0V
−20 mA
+20 mA
−0.5V to VCC + 0.5V
−20 mA
+20 mA
−0.5V to VCC + 0.5V
±50 mA
±50 mA
−65˚C to +150˚C
175˚C
Recommended Operating
Conditions
Supply Voltage (VCC)
’AC
2.0V to 6.0V
’ACT
4.5V to 5.5V
Input Voltage (VI)
Output Voltage (VO)
Operating Temperature (TA)
54AC/ACT
0V to VCC
0V to VCC
−55˚C to +125˚C
Minimum Input Edge Rate (V/t)
’AC Devices
VIN from 30% to 70% of VCC
VCC @ 3.3V, 4.5V, 5.5V
Minimum Input Edge Rate (V/t)
125 mV/ns
’ACT Devices
VIN from 0.8V to 2.0V
VCC @ 4.5V, 5.5V
125 mV/ns
Note 1: Absolute maximum ratings are those values beyond which damage
to the device may occur. The databook specifications should be met, without
exception, to ensure that the system design is reliable over its power supply,
temperature, and output/input loading variables. National does not recom-
mend operation of FACT® circuits outside databook specifications.
Note 2: All outputs loaded; thresholds on input associated with output under
test.
DC Characteristics for ’AC Family Devices
Symbol
Parameter
VIH Minimum High Level
Input Voltage
VIL Maximum Low Level
Input Voltage
VOH Minimum High Level
Output Voltage
VOL Maximum Low Level
Output Voltage
IIN Maximum Input
Leakage Current
54AC
VCC
TA = −55˚C to +125˚C
Units
(V) Guaranteed Limits
Conditions
3.0 2.1
4.5 3.15
5.5 3.85
VOUT = 0.1V
V or VCC − 0.1V
3.0 0.9
4.5 1.35
5.5 1.65
VOUT = 0.1V
V or VCC − 0.1V
3.0 2.9
4.5 4.4
IOUT = −50 µA
V
5.5 5.4
(Note 2)
3.0 2.4
4.5 3.7
5.5 4.7
3.0 0.1
4.5 0.1
VIN = VIL or VIH
IOH = −12 mA
V IOH = −24 mA
IOH = −24 mA
IOUT = 50 µA
V
5.5 0.1
(Note 2)
VIN = VIL or VIH
3.0 0.50
IOL = 12 mA
4.5 0.50
V IOL = 24 mA
5.5 0.50
IOL = 24 mA
5.5 ±1.0 µA VI = VCC, GND
www.national.com
4

No Preview Available !

DC Characteristics for ’AC Family Devices (Continued)
Symbol
Parameter
IOZ Maximum TRI-STATE
Current
54AC
VCC TA = −55˚C to +125˚C
(V) Guaranteed Limits
5.5 ±5.0
IOLD
IOHD
ICC
Minimum Dynamic
Output Current (Note 3)
Maximum Quiescent
Supply Current
5.5
5.5
5.5
50
−50
80.0
Note 3: Maximum test duration 2.0 ms, one output loaded at a time.
Note 4: IIN and ICC @ 3.0V are guaranteed to be less than or equal to the respective limit @ 5.5V VCC.
ICC for 54AC @ 25˚C is identical to 74AC @ 25˚C.
DC Characteristics for ’ACT Family Devices
Symbol
Parameter
VIH Minimum High Level
Input Voltage
VIL Maximum Low Level
Input Voltage
VOH Minimum High Level
Output Voltage
54ACT
VCC TA = −55˚C to +125˚C
(V) Guaranteed Limits
4.5 2.0
5.5 2.0
4.5 0.8
5.5 0.8
4.5 4.4
5.5 5.4
VOL Maximum Low Level
Output Voltage
4.5
5.5
4.5
5.5
3.70
4.70
0.1
0.1
IIN
IOZ
ICCT
IOLD
IOHD
ICC
Maximum Input
Leakage Current
Maximum TRI-STATE
Current
Maximum ICC/Input
Minimum Dynamic
Output Current (Note 6)
Maximum Quiescent
Supply Current
4.5
5.5
5.5
5.5
5.5
5.5
5.5
5.5
Note 5: All outputs loaded; thresholds on input associated with output under test.
Note 6: Maximum test duration 2.0 ms, one output loaded at a time.
Note 7: ICC for 54ACT @ 25˚C is identical to 74ACT @ 25˚C.
0.50
0.50
±1.0
±5.0
1.6
50
−50
80.0
Units
Conditions
VI (OE) = VIL, VIH
µA VI = VCC, VGND
VO = VCC, GND
mA VOLD = 1.65V Max
mA VOHD = 3.85V Min
µA VIN = VCC or GND
Units
Conditions
V VOUT = 0.1V
or VCC − 0.1V
V VOUT = 0.1V
or VCC − 0.1V
V IOUT = −50 µA
(Note 5)
VIN = VIL or VIH
V IOH = −24 mA
IOH = −24 mA
V IOUT = 50 µA
(Note 5)
VIN = VIL or VIH
V IOL = 24 mA
IOL = 24 mA
µA VI = VCC, GND
µA VI = VIL, VIH
VO = VCC, GND
mA VI = VCC − 2.1V
mA VOLD = 1.65V Max
mA VOHD = 3.85V Min
µA VIN = VCC
or GND
5 www.national.com