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74LVX157 Low Voltage Quad 2-Input Multiplexer
May 1993
Revised October 2003
74LVX157
Low Voltage Quad 2-Input Multiplexer
General Description
The LVX157 is a high-speed quad 2-input multiplexer. Four
bits of data from two sources can be selected using the
common Select and Enable inputs. The four outputs
present the selected data in the true (noninverted) form.
The LVX157 can also be used as a function generator.
Features
s
Input voltage level translation from 5V to 3V
s
Ideal for low power/low noise 3.3V applications
s
Guaranteed simultaneous switching noise level and
dynamic threshold performance
Ordering Code:
Order Number
74LVX157M
74LVX157SJ
74LVX157MTC
Package Number
M16A
M16D
MTC16
Package Description
16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150" Narrow
16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
16-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
Devices are also available in Tape and Reel. Specify by appending letter suffix “X” to the ordering code.
Logic Symbols
Connection Diagram
IEEE/IEC
Pin Descriptions
Pin Names
I
0a
–I
0d
I
1a
–I
1d
E
S
Z
a
–Z
d
Description
Source 0 Data Inputs
Source 1 Data Inputs
Enable Input
Select Input
Outputs
© 2003 Fairchild Semiconductor Corporation
DS011608
www.fairchildsemi.com
74LVX157
Truth Table
Inputs
E
H
L
L
L
L
H
=
HIGH Voltage Level
L
=
LOW Voltage Level
X
=
Immaterial
Outputs
I
0
X
X
X
L
H
I
1
X
L
H
X
X
Z
L
L
H
L
H
S
X
H
H
L
L
Functional Description
The LVX157 is a quad 2-input multiplexer. It selects four
bits of data from two sources under the control of a com-
mon Select input (S). The Enable input (E) is active-LOW.
When E is HIGH, all of the outputs (Z) are forced LOW
regardless of all other inputs. The LVX157 is the logic
implementation of a 4-pole, 2-position switch where the
position of the switch is determined by the logic levels sup-
plied to the Select input. The logic equations for the outputs
are shown below:
Z
a
=
E • (I
1a
• S
+
I
0a
• S)
Z
b
=
E • (I
1b
• S
+
I
0b
• S)
Z
c
=
E • (I
1c
• S
+
I
0c
• S)
Z
d
=
E • (I
1d
• S
+
I
0d
• S)
A common use of the LVX157 is the moving of data from
two groups of registers to four common output busses. The
particular register from which the data comes is determined
by the state of the Select input. A less obvious use is as a
function generator. The LVX157 can generate any four of
the sixteen different functions of two variables with one
variable common. This is useful for implementing gating
functions.
Logic Diagram
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2
74LVX157
Absolute Maximum Ratings
(Note 1)
Supply Voltage (V
CC
)
DC Input Diode Current (I
IK
)
V
I
= −
0.5V
DC Input Voltage (V
I
)
DC Output Diode Current (I
OK
)
V
O
= −
0.5V
V
O
=
V
CC
+
0.5V
DC Output Voltage (V
O
)
DC Output Source
or Sink Current (I
O
)
DC V
CC
or Ground Current
(I
CC
or I
GND
)
Storage Temperature (T
STG
)
Power Dissipation
−
0.5V to
+
7.0V
−
20 mA
−
0.5V to 7V
−
20 mA
+
20 mA
−
0.5V to V
CC
+
0.5V
±
25 mA
±
50 mA
−
65
°
C to
+
150
°
C
180 mW
Recommended Operating
Conditions
(Note 2)
Supply Voltage (V
CC
)
Input Voltage (V
I
)
Output Voltage (V
O
)
Operating Temperature (T
A
)
Input Rise and Fall Time (
∆
t/
∆
V)
2.0V to 3.6V
0V to 5.5V
0V to V
CC
−
40
°
C to
+
85
°
C
0 ns/V to 100 ns/V
Note 1:
The “Absolute Maximum Ratings” are those values beyond which
the safety of the device cannot be guaranteed. The device should not be
operated at these limits. The parametric values defined in the Electrical
Characteristics tables are not guaranteed at the absolute maximum ratings.
The “Recommended Operating Conditions” table will define the conditions
for actual device operation.
Note 2:
Unused inputs must be held HIGH or LOW. They may not float.
DC Electrical Characteristics
Symbol
V
IH
Parameter
HIGH Level
Input Voltage
V
IL
LOW Level
Input Voltage
V
OH
HIGH Level
Output Voltage
V
OL
LOW Level
Output Voltage
I
IN
I
CC
Input Leakage Current
Quiescent Supply Current
V
CC
2.0
3.0
3.6
2.0
3.0
3.6
2.0
3.0
3.0
2.0
3.0
3.0
3.6
3.6
1.9
2.9
2.58
0.0
0.0
0.1
0.1
0.36
±0.1
4.0
2.0
3.0
T
A
= +25°C
Min
1.5
2.0
2.4
0.5
0.8
0.8
1.9
2.9
2.48
0.1
0.1
0.44
±1.0
40.0
µA
µA
V
V
Typ
Max
T
A
= −40°C
to
+85°C
Min
1.5
2.0
2.4
0.5
0.8
0.8
V
IN
=
V
IL
or V
IH
I
OH
= −50 µA
I
OH
= −50 µA
I
OH
= −4
mA
V
IN
=
V
IL
or V
IH
I
OL
=
50
µA
I
OL
=
50
µA
I
OL
=
4 mA
V
IN
=
5.5V or GND
V
IN
=
V
CC
or GND
V
V
Max
Units
Conditions
Noise Characteristics
(Note 3)
Symbol
V
OLP
V
OLV
V
IHD
V
ILD
Parameter
Quiet Output Maximum Dynamic V
OL
Quiet Output Minimum Dynamic V
OL
Minimum HIGH Level Dynamic Input Voltage
Maximum LOW Level Dynamic Input Voltage
V
CC
(V)
3.3
3.3
3.3
3.3
T
A
=
25°C
Typ
0.3
−0.3
Limit
0.5
−0.5
2.0
0.8
V
V
V
V
Units
C
L
(pF)
50
50
50
50
Note 3:
Input t
r
=
t
f
=
3ns
3
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74LVX157
AC Electrical Characteristics
Symbol
t
PLH
t
PHL
Parameter
Propagation
Delay Time
I
n
to Z
n
t
PLH
t
PHL
Propagation
Delay Time
S to Z
n
t
PLH
t
PHL
Propagation
Delay Time
E to Z
n
t
OSHL
t
OSLH
Output to Output
Skew (Note 4)
3.3
±
0.3
2.7
3.3
3.3
±
0.3
2.7
3.3
±
0.3
2.7
V
CC
(V)
2.7
Min
T
A
= +25°C
Typ
6.6
9.1
5.1
7.6
8.9
11.4
7.0
9.5
9.1
11.6
7.2
9.7
Max
12.5
16.0
7.9
11.4
16.9
20.4
11.0
14.5
17.6
21.1
11.5
15.0
1.5
1.5
T
A
= −40°C
to
+85°C
Min
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
Max
15.5
19.0
9.5
13.0
20.5
24.0
13.0
16.5
20.5
24.0
13.5
17.0
1.5
1.5
ns
ns
ns
ns
Units
C
L
(pF)
15
50
15
50
15
50
15
50
15
50
15
50
50
Note 4:
Parameter guaranteed by design.
t
OSLH
=
|t
PLHm
−
t
PLHn
|.
t
OSHL
=
|t
PHLm
−
t
PHLn
|.
Capacitance
Symbol
C
IN
C
PD
Input Capacitance
Power Dissipation Capacitance (Note 5)
Parameter
T
A
= +25°C
Min
Typ
4
20
Max
10
T
A
= −40°C
to
+85°C
Min
Max
10
Units
pF
pF
Note 5:
C
PD
is defined as the value of the internal equivalent capacitance which is calculated from the operating current consumption without load.
Average operating current can be obtained by the equation: I
CC(opr.)
=
C
PD
×
V
CC
×
f
IN
+
I
CC
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