74LVX257
LOW VOLTAGE CMOS QUAD 2 CHANNEL MULTIPLEXER
(3-STATE) WITH 5V TOLERANT INPUTS
s
s
s
s
s
s
s
s
s
s
s
HIGH SPEED:
t
PD
=5.8ns (TYP.) at V
CC
= 3.3V
5V TOLERANT INPUTS
POWER-DOWN PROTECTION ON INPUTS
INPUT VOLTAGE LEVEL:
V
IL
= 0.8V, V
IH
= 2V at V
CC
=3V
LOW POWER DISSIPATION:
I
CC
= 4
µA
(MAX.) at T
A
=25°C
LOW NOISE:
V
OLP
= 0.3V (TYP.) at V
CC
=3.3V
SYMMETRICAL OUTPUT IMPEDANCE:
|I
OH
| = I
OL
= 4 mA (MIN) at V
CC
=3V
BALANCED PROPAGATION DELAYS:
t
PLH
≅
t
PHL
OPERATING VOLTAGE RANGE:
V
CC
(OPR) = 2V to 3.6V (1.2V Data Retention)
PIN AND FUNCTION COMPATIBLE WITH
74 SERIES 257
IMPROVED LATCH-UP IMMUNITY
SOP
TSSOP
Table 1: Order Codes
PACKAGE
SOP
TSSOP
DESCRIPTION
The 74LVX257 is a low voltage CMOS QUAD 2
CHANNEL MULTIPLEXER (3-STATE) fabricated
with sub-micron silicon gate and double-layer
metal wiring C
2
MOS technology. It is ideal for low
power, battery operated and low noise 3.3V
applications.
It is composed of four independent 2-channel
multiplexers with common SELECT and ENABLE
(OE) INPUT. The 74LVX257 is a non-inverting
Figure 1: Pin Connection And IEC Logic Symbols
O
et
l
so
b
ro
P
e
uc
d
s)
t(
multiplexer. When the ENABLE INPUT is held
"High", all outputs become in high impedance
state. If SELECT INPUT is held "Low", "A" data is
selected, when SELECT INPUT is "High", "B" data
is chosen.
Power down protection is provided on all inputs
and 0 to 7V can be accepted on inputs with no
regard to the supply voltage.
This device can be used to interface 5V to 3V. It
combines high speed performance with the true
CMOS low power consumption.
All inputs and outputs are equipped with
protection circuits against static discharge, giving
them 2KV ESD immunity and transient excess
voltage.
O
-
so
b
te
le
ro
P
uc
d
s)
t(
T&R
74LVX257MTR
74LVX257TTR
August 2004
Rev. 3
1/13
74LVX257
Table 4: Absolute Maximum Ratings
Symbol
V
CC
V
I
V
O
I
IK
I
OK
I
O
T
stg
T
L
Supply Voltage
DC Input Voltage
DC Output Voltage
DC Input Diode Current
DC Output Diode Current
DC Output Current
Storage Temperature
Lead Temperature (10 sec)
Parameter
Value
-0.5 to +7.0
-0.5 to +7.0
-0.5 to V
CC
+ 0.5
- 20
±
20
±
25
±
50
-65 to +150
300
Unit
V
V
V
mA
mA
mA
mA
°C
°C
I
CC
or I
GND
DC V
CC
or Ground Current
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is
not implied
Table 5: Recommended Operating Conditions
Symbol
V
CC
V
I
V
O
T
op
dt/dv
Supply Voltage (note 1)
Input Voltage
Output Voltage
Operating Temperature
Input Rise and Fall Time (note 2) (V
CC
= 3V)
Parameter
Value
1) Truth Table guaranteed: 1.2V to 3.6V
2) V
IN
from 0.8V to 2.0V
Table 6: DC Specifications
Symbol
Parameter
V
IH
V
IL
O
et
l
so
b
High Level Input
Voltage
Low Level Input
Voltage
ro
P
e
V
CC
(V)
2.0
3.0
3.6
2.0
3.0
3.6
2.0
3.0
3.0
2.0
3.0
3.0
Test Condition
T
A
= 25°C
Min.
1.5
2.0
2.4
0.5
0.8
0.8
I
O
=-50
µA
I
O
=-50
µA
I
O
=-4 mA
I
O
=50
µA
I
O
=50
µA
I
O
=4 mA
V
I
= V
IH
or V
IL
V
O
= V
CC
or GND
V
I
= 5.5V or GND
V
I
= V
CC
or GND
1.9
2.9
2.58
0.0
0.0
0.1
0.1
0.36
±0.25
±
0.1
4
2.0
3.0
Typ.
Max.
uc
d
s)
t(
O
-
s
b
te
le
o
Value
2 to 3.6
0 to 5.5
ro
P
uc
d
s)
t(
Unit
V
V
V
°C
ns/V
0 to V
CC
0 to 100
-55 to 125
-40 to 85°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
±
2.5
±
1
40
Max.
-55 to 125°C
Min.
1.5
2.0
2.4
0.5
0.8
0.8
1.9
2.9
2.4
0.1
0.1
0.55
±
5
±
1
40
Max.
Unit
V
V
V
OH
High Level Output
Voltage
V
V
OL
Low Level Output
Voltage
V
I
OZ
I
I
I
CC
High Impedance
Output Leakage
Current
Input Leakage
Current
Quiescent Supply
Current
3.6
3.6
3.6
µA
µA
µA
3/13
74LVX257
Table 7: Dynamic Switching Characteristics
Test Condition
Symbol
Parameter
V
CC
(V)
3.3
T
A
= 25°C
Min.
Typ.
0.3
-0.5
C
L
= 50 pF
2.0
-0.3
V
Max.
0.5
Value
-40 to 85°C
Min.
Max.
-55 to 125°C
Min.
Max.
Unit
V
OLP
V
OLV
V
IHD
V
ILD
Dynamic Low
Voltage Quiet
Output (note 1, 2)
Dynamic High
Voltage Input
(note 1, 3)
Dynamic Low
Voltage Input
(note 1, 3)
3.3
3.3
0.8
1) Worst case package.
2) Max number of outputs defined as (n). Data inputs are driven 0V to 3.3V, (n-1) outputs switching and one output at GND.
3) Max number of data inputs (n) switching. (n-1) switching 0V to 3.3V. Inputs under test switching: 3.3V to threshold (V
ILD
), 0V to threshold
(V
IHD
), f=1MHz.
Table 8: AC Electrical Characteristics
(Input t
r
= t
f
= 3ns)
Test Condition
Symbol
Parameter
V
CC
(V)
2.7
2.7
3.3
(*)
3.3
(*)
2.7
2.7
3.3
(*)
2.7
2.7
3.3
(*)
2.7
3.3
(*)
2.7
3.3
(*)
C
L
(pF)
15
50
15
50
15
50
T
A
= 25°C
Min.
t
PLH
t
PHL
Propagation Delay
Time
A, B, to Y
t
PLH
t
PHL
Propagation Delay
Time
SELECT to Y
t
PZL
t
PZH
t
PLZ
t
PHZ
O
et
l
so
b
Output Enable
Time
ro
P
e
3.3
(*)
3.3
(*)
15
50
15
50
uc
d
)-
(s
t
b
O
Typ.
7.0
9.5
5.8
8.3
8.5
10.5
7.0
9.5
8.0
10.5
6.7
9.2
9.5
8.6
0.5
0.5
so
Max.
13.0
18.0
9.3
12.8
15.4
20.3
11.0
14.5
14.7
19.6
10.5
14.0
16.8
12.0
1.0
1.0
te
le
Value
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
1.0
1.0
ro
P
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
1.0
1.0
uc
d
Max.
16.4
21.3
12.0
15.5
20.0
24.5
14.0
18.0
18.5
24.0
13.5
17.0
20.0
15.0
1.5
1.5
s)
t(
-40 to 85°C
Max.
15.4
20.3
11.0
14.5
18.2
23.1
13.0
16.5
17.5
22.4
12.5
16.0
18.9
13.5
1.5
1.5
-55 to 125°C
Unit
ns
ns
15
50
50
50
50
50
ns
Output Disable
Time
Output to Output
Skew Time (note
1,2)
ns
t
OSLH
t
OSHL
ns
1) Skew is defined as the absolute value of the difference between the actual propagation delay for any two outputs of the same device switch-
ing in the same direction, either HIGH or LOW
2) Parameter guaranteed by design
(*) Voltage range is 3.3V
±
0.3V
4/13
74LVX257
Table 9: Capacitive Characteristics
Test Condition
Symbol
Parameter
V
CC
(V)
3.3
3.3
3.3
T
A
= 25°C
Min.
Typ.
4
6
23
Max.
10
Value
-40 to 85°C
Min.
Max.
10
-55 to 125°C
Min.
Max.
10
pF
pF
pF
Unit
C
IN
C
OUT
C
PD
Input Capacitance
Output
Capacitance
Power Dissipation
Capacitance
(note 1)
1) C
PD
is defined as the value of the IC’s internal equivalent capacitance which is calculated from the operating current consumption without
load. (Refer to Test Circuit). Average operating current can be obtained by the following equation. I
CC(opr)
= C
PD
x V
CC
x f
IN
+ I
CC
/4 (per
channel)
Figure 4: Test Circuit
t
PLH
, t
PHL
t
PZL
, t
PLZ
t
PZH
, t
PHZ
C
L
=15/50pF or equivalent (includes jig and probe capacitance)
R
L
= R1 = 1KΩ or equivalent
R
T
= Z
OUT
of pulse generator (typically 50Ω)
O
et
l
so
b
ro
P
e
uc
d
s)
t(
O
-
so
b
te
le
ro
P
uc
d
s)
t(
TEST
SWITCH
Open
V
CC
GND
5/13
工业自动化与控制
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
