1/10
July 2001
s
HIGH SPEED:
t
PD
=5.8ns (TYP.) at V
CC
= 3.3V
s
5V TOLERANT INPUTS
s
POWER-DOWN PROTECTION ON INPUTS
s
INPUT VOLTAGE LEVEL:
V
IL
= 0.8V, V
IH
= 2V at V
CC
=3V
s
LOW POWER DISSIPATION:
I
CC
= 4
A (MAX.) at T
A
=25C
s
LOW NOISE:
V
OLP
= 0.3V (TYP.) at V
CC
=3.3V
s
SYMMETRICAL OUTPUT IMPEDANCE:
|I
OH
| = I
OL
= 4 mA (MIN) at V
CC
=3V
s
BALANCED PROPAGATION DELAYS:
t
PLH
t
PHL
s
OPERATING VOLTAGE RANGE:
V
CC
(OPR) = 2V to 3.6V (1.2V Data Retention)
s
PIN AND FUNCTION COMPATIBLE WITH
74 SERIES 257
s
IMPROVED LATCH-UP IMMUNITY
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
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.
74LVX257
LOW VOLTAGE CMOS QUAD 2 CHANNEL MULTIPLEXER
(3-STATE) WITH 5V TOLERANT INPUTS
PIN CONNECTION AND IEC LOGIC SYMBOLS
ORDER CODES
PACKAGE
TUBE
T & R
SOP
74LVX257M
74LVX257MTR
TSSOP
74LVX257TTR
TSSOP
SOP
74LVX257
2/10
INPUT EQUIVALENT CIRCUIT
PIN DESCRIPTION
TRUTH TABLE
X :Don`t Care
Z : High Impedance
LOGIC DIAGRAM
This logic diagram has not be used to estimate propagation delays
PIN No
SYMBOL
NAME AND FUNCTION
1
SELECT
Common Data Select
Inputs
2, 5, 11, 14
1A to 4A
Data Inputs From Source
A
3, 6, 10, 13
1B to 4B
Data Inputs From Source
B
4, 7, 9, 12
1Y to 4Y
3 State Multiplexer
Outputs
15
OE
3 State Output Enable
Inputs (Active LOW)
8
GND
Ground (0V)
16
V
CC
Positive Supply Voltage
INPUTS
OUTPUT
OE
SELECT
A
B
Y
H
X
X
X
Z
L
L
L
X
L
L
L
H
X
H
L
H
X
L
L
L
H
X
H
H
74LVX257
3/10
ABSOLUTE MAXIMUM RATINGS
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is
not implied
RECOMMENDED OPERATING CONDITIONS
1) Truth Table guaranteed: 1.2V to 3.6V
2) V
IN
from 0.8V to 2.0V
DC SPECIFICATIONS
Symbol
Parameter
Value
Unit
V
CC
Supply Voltage
-0.5 to +7.0
V
V
I
DC Input Voltage
-0.5 to +7.0
V
V
O
DC Output Voltage
-0.5 to V
CC
+ 0.5
V
I
IK
DC Input Diode Current
- 20
mA
I
OK
DC Output Diode Current
20
mA
I
O
DC Output Current
25
mA
I
CC
or I
GND
DC V
CC
or Ground Current
50
mA
T
stg
Storage Temperature
-65 to +150
C
T
L
Lead Temperature (10 sec)
300
C
Symbol
Parameter
Value
Unit
V
CC
Supply Voltage (note 1)
2 to 3.6
V
V
I
Input Voltage
0 to 5.5
V
V
O
Output Voltage
0 to V
CC
V
T
op
Operating Temperature
-55 to 125
C
dt/dv
Input Rise and Fall Time (note 2) (V
CC
= 3V)
0 to 100
ns/V
Symbol
Parameter
Test Condition
Value
Unit
V
CC
(V)
T
A
= 25C
-40 to 85C
-55 to 125C
Min.
Typ.
Max.
Min.
Max.
Min.
Max.
V
IH
High Level Input
Voltage
2.0
1.5
1.5
1.5
V
3.0
2.0
2.0
2.0
3.6
2.4
2.4
2.4
V
IL
Low Level Input
Voltage
2.0
0.5
0.5
0.5
V
3.0
0.8
0.8
0.8
3.6
0.8
0.8
0.8
V
OH
High Level Output
Voltage
2.0
I
O
=-50
A
1.9
2.0
1.9
1.9
V
3.0
I
O
=-50
A
2.9
3.0
2.9
2.9
3.0
I
O
=-4 mA
2.58
2.48
2.4
V
OL
Low Level Output
Voltage
2.0
I
O
=50
A
0.0
0.1
0.1
0.1
V
3.0
I
O
=50
A
0.0
0.1
0.1
0.1
3.0
I
O
=4 mA
0.36
0.44
0.55
I
OZ
High Impedance
Output Leakage
Current
3.6
V
I
= V
IH
or V
IL
V
O
= V
CC
or GND
0.25
2.5
5
A
I
I
Input Leakage
Current
3.6
V
I
= 5.5V or GND
0.1
1
1
A
I
CC
Quiescent Supply
Current
3.6
V
I
= V
CC
or GND
4
40
40
A
74LVX257
4/10
DYNAMIC SWITCHING CHARACTERISTICS
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.
AC ELECTRICAL CHARACTERISTICS (Input t
r
= t
f
= 3ns)
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
Symbol
Parameter
Test Condition
Value
Unit
V
CC
(V)
T
A
= 25C
-40 to 85C
-55 to 125C
Min.
Typ.
Max.
Min.
Max.
Min.
Max.
V
OLP
Dynamic Low
Voltage Quiet
Output (note 1, 2)
3.3
C
L
= 50 pF
0.3
0.5
V
V
OLV
-0.5
-0.3
V
IHD
Dynamic High
Voltage Input
(note 1, 3)
3.3
2.0
V
ILD
Dynamic Low
Voltage Input
(note 1, 3)
3.3
0.8
Symbol
Parameter
Test Condition
Value
Unit
V
CC
(V)
C
L
(pF)
T
A
= 25C
-40 to 85C
-55 to 125C
Min.
Typ.
Max.
Min.
Max.
Min.
Max.
t
PLH
t
PHL
Propagation Delay
Time
A, B, to Y
2.7
15
7.0
13.0
1.0
15.4
1.0
16.4
ns
2.7
50
9.5
18.0
1.0
20.3
1.0
21.3
3.3
(*)
15
5.8
9.3
1.0
11.0
1.0
12.0
3.3
(*)
50
8.3
12.8
1.0
14.5
1.0
15.5
t
PLH
t
PHL
Propagation Delay
Time
SELECT to Y
2.7
15
8.5
15.4
1.0
18.2
1.0
20.0
ns
2.7
50
10.5
20.3
1.0
23.1
1.0
24.5
3.3
(*)
15
7.0
11.0
1.0
13.0
1.0
14.0
3.3
(*)
50
9.5
14.5
1.0
16.5
1.0
18.0
t
PZL
t
PZH
Output Enable
Time
2.7
15
8.0
14.7
1.0
17.5
1.0
18.5
ns
2.7
50
10.5
19.6
1.0
22.4
1.0
24.0
3.3
(*)
15
6.7
10.5
1.0
12.5
1.0
13.5
3.3
(*)
50
9.2
14.0
1.0
16.0
1.0
17.0
t
PLZ
t
PHZ
Output Disable
Time
2.7
50
9.5
16.8
1.0
18.9
1.0
20.0
ns
3.3
(*)
50
8.6
12.0
1.0
13.5
1.0
15.0
t
OSLH
t
OSHL
Output to Output
Skew Time (note
1,2)
2.7
50
0.5
1.0
1.5
1.5
ns
3.3
(*)
50
0.5
1.0
1.5
1.5
74LVX257
5/10
CAPACITIVE CHARACTERISTICS
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)
TEST CIRCUIT
C
L
=15/50pF or equivalent (includes jig and probe capacitance)
R
L
= R1 = 1K
or equivalent
R
T
= Z
OUT
of pulse generator (typically 50
)
Symbol
Parameter
Test Condition
Value
Unit
V
CC
(V)
T
A
= 25C
-40 to 85C
-55 to 125C
Min.
Typ.
Max.
Min.
Max.
Min.
Max.
C
IN
Input Capacitance
3.3
4
10
10
10
pF
C
OUT
Output
Capacitance
3.3
6
pF
C
PD
Power Dissipation
Capacitance
(note 1)
3.3
23
pF
TEST
SWITCH
t
PLH
, t
PHL
Open
t
PZL
, t
PLZ
V
CC
t
PZH
, t
PHZ
GND
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