NSC MM74HCT251

MM54HCT251/MM74HCT251
8-Channel TRI-STATEÉ Multiplexer
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
outputs.
Connection and Logic Diagrams
MM54HCT/MM74HCT devices are intended to interface between TTL and NMOS components and standard CMOS
devices. These parts are also plug-in replacements for LSTTL devices and can be used to reduce power consumption
in existing designs.
Features
Y
Y
Y
Y
Y
Typical propagation delay: 20 ns
Low quiescent current: 40 mA maximum (74HCT Series)
Low input current: 1 mA maximum
Fanout of 10 LS-TTL loads
TTL input compatible
Truth Table
Dual-in-Line Package
Inputs
Select
Outputs
W
B
A
Strobe
S
Y
C
X
L
L
L
L
H
H
H
H
X
L
L
H
H
L
L
H
H
X
L
H
L
H
L
H
L
H
H
L
L
L
L
L
L
L
L
Z
D0
D1
D2
D3
D4
D5
D6
D7
Z
D0
D1
D2
D3
D4
D5
D6
D7
TL/F/9401 – 1
Top View
Order Number MM54HCT251 or MM74HCT251
H e high logic level, L e logic level
X e irrelevant, Z e high impedance (off)
D0, D1 . . . D7 e the level of the respective D input
TL/F/9401 – 2
TRI-STATEÉ is a registered trademark of National Semiconductor Corporation.
C1995 National Semiconductor Corporation
TL/F/9401
RRD-B30M115/Printed in U. S. A.
MM54HCT251/MM74HCT251 8-Channel TRI-STATE Multiplexer
November 1995
Absolute Maximum Ratings (Notes 1 & 2)
Operating Conditions
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales
Office/Distributors for availability and specifications.
Supply Voltage (VCC)
DC Input or Output Voltage
(VIN, VOUT)
b 0.5V to a 7.0V
Supply Voltage (VCC)
b 1.5V to VCC a 1.5V
DC Input Voltage (VIN)
b 0.5V to VCC a 0.5V
DC Output Voltage (VOUT)
g 20 mA
Clamp Diode Current (IIK, IOK)
g 35 mA
DC Output Current, per Pin (IOUT)
g 70 mA
DC VCC or GND Current, per Pin (ICC)
b 65§ C to a 150§ C
Storage Temperature Range (TSTG)
Power Dissipation (PD)
(Note 3)
600 mW
S.O. Package only
500 mW
Lead Temp. (TL) (Soldering, 10 seconds)
260§ C
Operating Temp. Range (TA)
MM74HCT
MM54HCT
Min
2
Max
6
0
VCC
Units
V
V
b 40
b 55
a 85
a 125
§C
§C
500
ns
Input Rise or Fall Times
(tr, tf)
VCC e 4.5V
DC Electrical Characteristics (Note 4) VCC e 5V g 10%
Symbol
Parameter
Conditions
TA e 25§ C
74HCT
54HCT
TA eb40§ C to a 85§ C TA eb55§ C to a 125§ C Units
Typ
Guaranteed Limits
VIH
Minimum High Level
Input Voltage
2.0
2.0
2.0
V
VIL
Maximum Low Level
Input Voltage
0.8
0.8
0.8
V
VOH
Minimum High Level
Output Voltage
VOL
Maximum Low Level
Output Voltage
VIN e VIH or VIL
lIOUTl s20 mA
4.5
4.4
4.4
4.4
V
VIN e VIH or VIL
lIOUTl s4.0 mA, VCC e 4.5V
lIOUTl s4.8 mA, VCC e 5.5V
4.2
5.2
3.98
4.98
3.84
4.84
3.7
4.7
V
V
0
0.1
0.1
0.1
V
0.2
0.2
0.26
0.26
0.33
0.33
0.4
0.4
V
V
g 0.1
g 1.0
g 1.0
mA
g 0.5
g 5.0
g 10
mA
8.0
80
160
mA
0.4
0.55
0.65
mA
VIN e VIH or VIL
lIOUTl s20 mA
VIN e VIH or VIL
lIOUTl s4.0 mA, VCC e 4.5V
lIOUTl s4.8 mA, VCC e 5.5V
IIN
Maximum Input
Current
VIN e VCC or GND
IOZ
Maximum TRI-STATE VOUT e VCC or GND
Output Leakage
STROBE e VCC
ICC
Maximum Quiescent
Supply Current
VIN e VCC or GND
IOUT e 0 mA
VIN e 2.4V or 0.5V
0.25
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: b 12 mW/§ C from 65§ C to 85§ C; ceramic ‘‘J’’ package: b 12 mW/§ C from 100§ C to 125§ C.
Note 4: For a power supply of 5V 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 this supply. Worst case VIH and VIL occur at VCC e 5.5V and 4.5V respectively. (The VIH value at 5.5V is 3.85V.) The worst case leakage current (IIN, ICC, and
IOZ) occur for CMOS at the higher voltage and so the 6.0V values should be used.
2
AC Electrical Characteristics VCC e 5V, TA e 25§ C, CL e 15 pF, tr e tf e 6 ns
Symbol
Parameter
Conditions
Typ
Guaranteed
Limit
Units
tPHL, tPLH
Maximum Propagation Delay
A, B or C to Y
26
35
ns
tPHL, tPLH
Maximum Propagation
Delay, A, B or C to W
27
35
ns
tPHL, tPLH
Maximum Propagation
Delay, Any D to Y
22
31
ns
tPHL, tPLH
Maximum Propagation
Delay, Any D to W
24
32
ns
tPZH, tPZL
Maximum Output Enable
Time, W Output
RL e 1 kX
CL e 50 pF
19
27
ns
tPZH, tPZL
Maximum Output Enable
Time, Y Output
RL e 1 kX
CL e 50 pF
19
26
ns
tPHZ, tPLZ
Maximum Output Disable Time
W Output
RL e 1 kX
CL e 5 pF
26
40
ns
tPHZ, tPLZ
Maximum Output Disable Time
Y Output
RL e 1 kX
CL e 5 pF
27
40
ns
AC Electrical Characteristics
Symbol
Parameter
VCC e 5.0V g 10%, CL e 50 pF, tr e tf e 6 ns (unless otherwise specified)
Conditions
TA e 25§ C
Typ
74HC
54HC
TA eb40§ C to a 85§ C TA eb55§ C to a 125§ C Units
Guaranteed Limits
tPHL, tPLH Maximum Propagation Delay
A, B or C to Y
33
46
58
69
ns
tPHL, tPLH Maximum Propagation
Delay, A, B or C to W
33
46
58
69
ns
tPHL, tPLH Maximum Propagation
Delay, any D to Y
27
40
50
60
ns
tPHL, tPLH Maximum Propagation
Delay, any D to W
27
40
50
60
ns
tPZH, tPZL Maximum Output Enable Time
W Output
RL e 1 kX
21
30
38
45
ns
tPZH, tPZL Maximum Output Enable Time
Y Output
RL e 1 kX
21
30
38
45
ns
tPHZ, tPLZ Maximum Output Disable Time RL e 1 kX
22
40
50
60
ns
tPHZ, tPLZ Maximum Output Disable Time RL e 1 kX
Y Output
23
40
50
60
ns
tTHL, tTLH Maximum Output Rise
and Fall Time
8
15
19
23
ns
W Output
CPD
Power Dissipation
Capacitance (Note 5)
CIN
Maximum Input
Capacitance
(per Package)
110
pF
5
10
pF
Note 5: CPD determines the no load dynamic power consumption, PD e CPD VCC2 f a ICC VCC, and the no load dynamic current consumption, IS e CPD VCC f a ICC.
3
MM54HCT251/MM74HCT251 8-Channel TRI-STATE Multiplexer
Physical Dimensions inches (millimeters)
Ceramic Dual-In-Line Package (J)
Order Number MM54HCT521J or MM74HCT521J
NS Package Number J16A
Molded Dual-In-Line Package (N)
Order Number MM74HCT251N
NS Package Number N16E
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