74LCX257
LOW VOLTAGE CMOS QUAD 2 CHANNEL MULTIPLEXER
WITH 5V TOLERANT INPUTS AND OUTPUTS (3-STATE)
s
s
s
s
s
s
s
s
s
s
5V TOLERANT INPUTS AND OUTPUTS
HIGH SPEED:
t
PD
= 6.0 ns (MAX.) at V
CC
= 3V
POWER DOWN PROTECTION ON INPUTS
AND OUTPUTS
SYMMETRICAL OUTPUT IMPEDANCE:
|I
OH
| = I
OL
= 24mA (MIN) at V
CC
= 3V
PCI BUS LEVELS GUARANTEED AT 24 mA
BALANCED PROPAGATION DELAYS:
t
PLH
≅
t
PHL
OPERATING VOLTAGE RANGE:
V
CC
(OPR) = 2.0V to 3.6V (1.5V Data
Retention)
PIN AND FUNCTION COMPATIBLE WITH
74 SERIES 257
LATCH-UP PERFORMANCE EXCEEDS
500mA (JESD 17)
ESD PERFORMANCE:
HBM > 2000V (MIL STD 883 method 3015);
MM > 200V
SOP
TSSOP
Table 1: Order Codes
PACKAGE
SOP
TSSOP
DESCRIPTION
The 74LCX257 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 and high speed 3.3V applications; it can be
interfaced to 5V signal environment for both inputs
and outputs.
Figure 1: Pin Connection And IEC Logic Symbols
te
le
so
b
O
ro
P
uc
d
s)
t(
It is composed of four independent 2 channel
multiplexers with common SELECT and ENABLE
(OE) INPUT. The 74LCX257 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.
It has same speed performance at 3.3V than 5V
AC/ACT family, combined with a lower 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
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le
r
P
e
du
o
T&R
s)
t(
c
74LCX257MTR
74LCX257TTR
September 2004
Rev. 4
1/13
74LCX257
Figure 2: Input And Output Equivalent Circuit
Table 2: Pin Description
PIN N°
1
2, 5, 11, 14
3, 6, 10, 13
4, 7, 9, 12
15
8
16
SYMBOL
SELECT
1A to 4A
1B to 4B
1Y to 4Y
OE
GND
V
CC
Table 3: Truth Table
OE
SELECT
X
L
L
H
H
X : Don’t Care
Z : High Impedance
te
le
so
b
O
H
L
L
L
L
ro
P
uc
d
INPUTS
s)
t(
A
X
L
H
X
X
O
-
Common Data Select Inputs
Data Inputs From Source A
Data Inputs From Source B
3 State Multiplexer Outputs
3 State Output Enable Inputs (Active LOW)
Ground (0V)
Positive Supply Voltage
so
b
t
le
NAME AND FUNCTION
r
P
e
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o
s)
t(
c
OUTPUT
B
X
X
X
L
H
Y
Z
L
H
L
H
2/13
74LCX257
Figure 3: Logic Diagram
This logic diagram has not be used to estimate propagation delays
Table 4: Absolute Maximum Ratings
Symbol
V
CC
V
I
V
O
V
O
I
IK
I
O
I
OK
Supply Voltage
DC Input Voltage
Parameter
DC Output Voltage (OFF State)
DC Input Diode Current
DC Output Current
DC Output Voltage (High or Low State) (note 1)
DC Output Diode Current (note 2)
DC Supply Current per Supply Pin
DC Ground Current per Supply Pin
Storage Temperature
Lead Temperature (10 sec)
I
GND
T
stg
T
L
te
le
so
b
O
I
CC
ro
P
uc
d
s)
t(
O
-
so
b
t
le
r
P
e
Value
du
o
s)
t(
c
Unit
V
V
V
V
mA
mA
mA
mA
mA
°C
°C
-0.5 to +7.0
-0.5 to +7.0
-0.5 to +7.0
-0.5 to V
CC
+ 0.5
- 50
- 50
±
50
±
100
±
100
-65 to +150
300
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is
not implied
1) I
O
absolute maximum rating must be observed
2) V
O
< GND
3/13
74LCX257
Table 5: Recommended Operating Conditions
Symbol
V
CC
V
I
V
O
V
O
I
OH
, I
OL
I
OH
, I
OL
T
op
dt/dv
Supply Voltage (note 1)
Input Voltage
Output Voltage (OFF State)
Output Voltage (High or Low State)
High or Low Level Output Current (V
CC
= 3.0 to 3.6V)
High or Low Level Output Current (V
CC
= 2.7V)
Operating Temperature
Input Rise and Fall Time (note 2)
Parameter
Value
2.0 to 3.6
0 to 5.5
0 to 5.5
0 to V
CC
±
24
±
12
-55 to 125
0 to 10
Unit
V
V
V
V
mA
mA
°C
1) Truth Table guaranteed: 1.5V to 3.6V
2) V
IN
from 0.8V to 2V at V
CC
= 3.0V
Table 6: DC Specifications
Test Condition
Symbol
Parameter
V
CC
(V)
-40 to 85 °C
Min.
2.0
2.7 to 3.6
2.7 to 3.6
2.7
3.0
V
OL
Low Level Output
Voltage
Max.
Value
V
IH
V
IL
V
OH
High Level Input
Voltage
Low Level Input
Voltage
High Level Output
Voltage
et
l
so
b
O
I
I
I
off
I
OZ
I
CC
∆I
CC
Input Leakage
Current
Power Off Leakage
Current
High Impedance
Output Leakage
Current
Quiescent Supply
Current
I
CC
incr. per Input
P
e
od
r
2.7
3.0
0
2.7 to 3.6
uc
)-
(s
t
I
O
=-100
µA
I
O
=-12 mA
I
O
=-18 mA
I
O
=-24 mA
I
O
=100
µA
I
O
=12 mA
I
O
=16 mA
I
O
=24 mA
b
O
so
t
le
0.8
r
P
e
Min.
2.0
V
CC
-0.2
2.2
2.4
2.2
-55 to 125 °C
du
o
Max.
0.8
s)
t(
c
Unit
V
V
ns/V
V
CC
-0.2
2.2
2.4
2.2
0.2
0.4
0.4
0.55
±
5
10
±
5
10
±
10
500
V
0.2
0.4
0.4
0.55
±
5
10
±
5
10
±
10
500
µA
µA
µA
µA
µA
V
2.7 to 3.6
V
I
= 0 to 5.5V
V
I
or V
O
= 5.5V
V
I
= V
IH
or V
IL
V
O
= 0 to V
CC
V
I
= V
CC
or GND
V
I
or V
O
= 3.6 to 5.5V
V
IH
= V
CC
- 0.6V
2.7 to 3.6
2.7 to 3.6
2.7 to 3.6
4/13
74LCX257
Table 7: Dynamic Switching Characteristics
Test Condition
Symbol
Parameter
V
CC
(V)
3.3
C
L
= 50pF
V
IL
= 0V, V
IH
= 3.3V
Value
T
A
= 25 °C
Min.
Typ.
0.8
-0.8
Max.
V
Unit
V
OLP
V
OLV
Dynamic Low Level Quiet
Output (note 1)
1) Number of outputs defined as "n". Measured with "n-1" outputs switching from HIGH to LOW or LOW to HIGH. The remaining output is
measured in the LOW state.
Table 8: AC Electrical Characteristics
Test Condition
Symbol
Parameter
V
CC
(V)
2.7
3.0 to 3.6
2.7
3.0 to 3.6
2.7
3.0 to 3.6
2.7
3.0 to 3.6
3.0 to 3.6
C
L
(pF)
50
50
50
50
50
R
L
(Ω)
500
500
500
500
500
t
s
=
t
r
(ns)
2.5
2.5
2.5
2.5
2.5
-40 to 85 °C
Min.
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
Max.
6.5
6.0
8.5
7.0
8.5
7.0
6.0
5.5
1.0
Value
-55 to 125 °C
Min.
t
PLH
t
PHL
t
PLH
t
PHL
t
PZL
t
PZH
t
PLZ
t
PHZ
t
OSLH
t
OSHL
Propagation Delay
Time (A, B to Y)
Propagation Delay
Time (SELECT to Y)
Output Enable Time
Output Disable Time
Output To Output
Skew Time (note1,
2)
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 (t
OSLH
= | t
PLHm
- t
PLHn
|, t
OSHL
= | t
PHLm
- t
PHLn
|)
2) Parameter guaranteed by design
Table 9: Capacitive Characteristics
Symbol
C
OUT
C
PD
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le
so
b
O
C
IN
ro
P
uc
d
)-
(s
t
b
O
so
t
le
r
P
e
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
du
o
Max.
6.5
6.0
8.5
7.0
8.5
7.0
6.0
5.5
1.0
s)
t(
c
Unit
ns
ns
ns
ns
ns
Test Condition
V
CC
(V)
3.3
3.3
3.3
V
IN
= 0 to V
CC
V
IN
= 0 to V
CC
f
IN
= 10MHz
V
IN
= 0 or V
CC
Value
T
A
= 25 °C
Min.
Typ.
7
8
25
Max.
pF
pF
pF
Unit
Parameter
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)
5/13
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