Page 1
MM54HC251/MM74HC251
8-Channel TRI-STATE
General Description
This 8-channel digital multiplexer with TRI-STATE outputs
utilizes advanced silicon-gate CMOS technology. Along with
the high noise immunity and low power consumption of
standard CMOS integrated circuits, it possesses the ability
to drive 10 LS-TTL loads. The large output drive capability
and TRI-STATE feature make this part ideally suited for interfacing with bus lines in a bus oriented system.
This multiplexer features both true (Y) and complement (W)
outputs as well as a STROBE input. The STROBE must be
at a low logic level to enable this device. When the STROBE
input is high, both outputs are in the high impedance state.
When enabled, address information on the data select inputs determines which data input is routed to the Y and W
Multiplexer
É
January 1988
outputs. The 54HC/74HC logic family is speed, function, as
well as pinout compatible with the standard 54LS/74LS logic family. All inputs are protected from damage due to static
discharge by internal diode clamps to V
and ground.
CC
Features
Y
Typical propagation delay
Data select to Y: 26 ns
Y
Wide supply range: 2 –6V
Y
Low power supply quiescent current: 80 mA maximum
(74HC)
Y
TRI-STATE outputs for interface to bus oriented
systems
MM54HC251/MM74HC251 8-Channel TRI-STATE Multiplexer
Connection and Logic Diagrams
Dual-in-Line Package
TL/F/5328– 1
Top View
Order Number MM54HC251 or MM74HC251
Truth Table
Inputs Outputs
Select
CBA S
XXX H Z Z
L L L L D0 D0
L L H L D1 D1
L H L L D2 D2
L H H L D3 D3
H L L L D4 D4
H L H L D5 D5
H H L L D6 D6
H H H L D7 D7
Hehigh logic level, Lelogic level
e
X
irrelevant, Zehigh impedance (off)
D0, D1 . . . D7
Strobe Y W
e
the level of the respective D input
TL/F/5328– 2
TRI-STATEÉis a registered trademark of National Semiconductor Corp.
C
1995 National Semiconductor Corporation RRD-B30M105/Printed in U. S. A.
TL/F/5328
Page 2
Absolute Maximum Ratings (Notes1&2)
Operating Conditions
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales
Office/Distributors for availability and specifications.
Supply Voltage (V
CC
)
DC Input Voltage (VIN)
DC Output Voltage (V
OUT
)
Clamp Diode Current (IIK,IOK)
DC Output Current, per pin (I
OUT
)
DC VCCor GND Current, per pin (ICC)
Storage Temperature Range (T
STG
b
b
)
b
0.5 toa7.0V
1.5 to V
CC
0.5 to V
CC
g
g
b
g
65§Ctoa150§C
a
1.5V
a
0.5V
20 mA
25 mA
50 mA
Supply Voltage (V
)26V
CC
DC Input or Output Voltage 0 V
(V
IN,VOUT
)
Operating Temp. Range (TA)
MM74HC
MM54HC
Input Rise or Fall Times
e
V
2.0V(tr,tf) 1000 ns
CC
e
V
4.5V 500 ns
CC
e
V
6.0V 400 ns
CC
Power Dissipation (PD)
(Note 3) 600 mW
S.O. Package only 500 mW
Lead Temp. (T
) (Soldering 10 seconds) 260§C
L
DC Electrical Characteristics (Note 4)
Symbol Parameter Conditions V
CC
A
e
T
25§C
Typ Guaranteed Limits
V
Minimum High Level 2.0V 1.5 1.5 1.5 V
IH
Input Voltage 4.5V 3.15 3.15 3.15 V
6.0V 4.2 4.2 4.2 V
V
Maximum Low Level 2.0V 0.5 0.5 0.5 V
IL
Input Voltage** 4.5V 1.35 1.35 1.35 V
6.0V 1.8 1.8 1.8 V
V
Minimum High Level V
OH
Output Voltage
e
VIHor V
l
IN
I
OUT
IL
s
20 mA 2.0V 2.0 1.9 1.9 1.9 V
l
4.5V 4.5 4.4 4.4 4.4 V
6.0V 6.0 5.9 5.9 5.9 V
e
V
VIHor V
IN
I
l
OUT
I
l
OUT
l
IN
I
OUT
e
V
Maximum Low Level V
OL
Output Voltage
IL
s
4.0 mA 4.5V 4.2 3.98 3.84 3.7 V
l
s
5.2 mA 6.0V 5.7 5.48 5.34 5.2 V
l
VIHor V
IL
s
20 mA 2.0V 0 0.1 0.1 0.1 V
l
4.5V 0 0.1 0.1 0.1 V
6.0V 0 0.1 0.1 0.1 V
e
V
VIHor V
IN
I
l
OUT
I
l
OUT
I
IN
I
OZ
Maximum Input V
Current
Maximum TRI- StrobeeV
STATE Leakage V
Current
I
CC
Note 1: Absolute Maximum Ratings are those values beyond which damage to the device may occur.
Note 2: Unless otherwise specified all voltages are referenced to ground.
Note 3: Power Dissipation temperature derating Ð plastic ‘‘N’’ package:
Note 4: For a power supply of 5V
this supply. Worst case V
CMOS at the higher voltage and so the 6.0V values should be used.
**V
Maximum Quiescent V
Supply Current I
g
10% the worst case output voltages (VOH, and VOL) occur for HC at 4.5V. Thus the 4.5V values should be used when designing with
and VILoccur at V
IH
limits are currently tested at 20% of VCC. The above VILspecification (30% of VCC) will be implemented no later than Q1, CY’89.
IL
e
IN
OUT
e
IN
OUT
e
5.5V and 4.5V respectively. (The VIHvalue at 5.5V is 3.85V.) The worst case leakage current (IIN,ICC, and IOZ) occur for
CC
IL
s
4.0 mA 4.5V 0.2 0.26 0.33 0.4 V
l
s
5.2 mA 6.0V 0.2 0.26 0.33 0.4 V
l
VCCor GND 6.0V
CC
e
VCCor GND
6.0V
g
0.1
g
0.5
VCCor GND 6.0V 8.0 80 160 mA
e
0 mA
b
12 mW/§C from 65§Cto85§C; ceramic ‘‘J’’ package:b12 mW/§C from 100§Cto125§C.
74HC 54HC
eb
T
40 to 85§CT
A
g
1.0
g
5
Min Max Units
V
§
§
Units
b
b
40
55
A
eb
55 to 125§C
g
g
CC
a
85
a
125
1.0 mA
10 mA
C
C
2
Page 3
AC Electrical Characteristics V
CC
e
5V, T
Symbol Parameter Conditions Typ
t
PHL,tPLH
t
PHL,tPLH
t
PHL,tPLH
t
PHL,tPLH
t
PZH,tPZL
t
PZH,tPZL
t
PHZ,tPLZ
t
PHZ,tPLZ
Maximum Propagation Delay 26 35 ns
A,BorCtoY
Maximum Propagation 27 35 ns
Delay, A, B or C to W
Maximum Propagation 22 29 ns
Delay, Any D to Y
Maximum Propagation 24 32 ns
Delay, Any D to W
Maximum Output Enable R
Time, W Output C
Maximum Output Enable R
Time, Y Output C
Maximum Output Disable Time R
W Output C
Maximum Output Disable Time R
Y Output C
e
1kX 19 27 ns
L
e
50 pF
L
e
1kX 19 26 ns
L
e
50 pF
L
e
1kX 26 40 ns
L
e
5pF
L
e
1kX 27 35 ns
L
e
5pF
L
e
A
25§C, C
e
15 pF, t
L
Guaranteed
Limit
r
e
e
t
f
Units
6ns
AC Electrical Characteristics C
e
L
50 pF, t
Symbol Parameter Conditions V
t
PHL,tPLH
t
PHL,tPLH
t
PHL,tPLH
t
PHL,tPLH
t
PZH,tPZL
t
PZH,tPZL
t
PHZ,tPLZ
t
PHZ,tPLZ
t
THL,tTLH
C
PD
C
IN
Note 5: CPDdetermines the no load dynamic power consumption, P
Maximum Propagation Delay 2.0V 90 205 256 300 ns
A, B or C to Y 4.5V 31 41 51 60 ns
Maximum Propagation 2.0V 95 205 256 300 ns
Delay, A, B or C to W 4.5V 32 41 51 60 ns
Maximum Propagation 2.0V 70 195 244 283 ns
Delay, any D to Y 4.5V 27 39 49 57 ns
Maximum Propagation 2.0V 75 185 231 268 ns
Delay, any D to W 4.5V 29 37 46 54 ns
Maximum Output Enable Time R
W Output 4.5V 21 30 38 44 ns
Maximum Output Enable Time R
Y Output 4.5V 21 29 36 42 ns
Maximum Output Disable Time R
W Output 4.5V 29 44 55 64 ns
Maximum Output Disable Time R
Y Output 4.5V 30 39 49 57 ns
Maximum Output Rise 2.0V 30 75 95 110 ns
and Fall Time 4.5V 8 15 19 22 ns
Power Dissipation (per package) 110 pF
Capacitance (Note 5)
Maximum Input 5 10 10 10 pF
Capacitance
e
1kX 2.0V 45 150 188 218 ns
L
e
1kX 2.0V 45 145 181 210 ns
L
e
1kX 2.0V 60 220 275 319 ns
L
e
1kX 2.0V 60 195 244 283 ns
L
e
CPDV
D
e
e
t
6 ns (unless otherwise specified)
r
CC
f
e
T
25§C
A
74HC 54HC
eb
T
40 to 85§CT
A
A
eb
55 to 125§C
Typ Guaranteed Limits
6.0V 26 35 44 51 ns
6.0V 27 35 44 51 ns
6.0V 23 33 41 48 ns
6.0V 25 32 40 46 ns
6.0V 18 26 33 38 ns
6.0V 18 25 31 36 ns
6.0V 25 37 46 54 ns
6.0V 26 33 41 48 ns
6.0V 7 13 16 19 ns
2
faICCVCC, and the no load dynamic current consumption, I
CC
e
CPDVCCfaICC.
S
Units
3
Page 4
Physical Dimensions inches (millimeters)
Order Number MM54HC1234J or
MM74HC1234J
NS Package J16A
MM54HC251/MM74HC251 8-Channel TRI-STATE Multiplexer
Order Number MM74HC1234N
NS Package N16E
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 2. A critical component is any component of a life
systems which, (a) are intended for surgical implant support device or system whose failure to perform can
into the body, or (b) support or sustain life, and whose be reasonably expected to cause the failure of the life
failure to perform, when properly used in accordance support device or system, or to affect its safety or
with instructions for use provided in the labeling, can effectiveness.
be reasonably expected to result in a significant injury
to the user.
National Semiconductor National Semiconductor National Semiconductor National Semiconductor
Corporation Europe Hong Kong Ltd. Japan Ltd.
1111 West Bardin Road Fax: (
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Tel: 1(800) 272-9959 Deutsch Tel: (
Fax: 1(800) 737-7018 English Tel: (
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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a
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