74LCX257 LOW VOLTAGE CMOS QUAD 2 CHANNEL   MULTIPLEXER
74LCX257
LOW VOLTAGE CMOS QUAD 2 CHANNEL MULTIPLEXER
WITH 5V TOLERANT INPUTS AND OUTPUTS (3-STATE)
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5V TOLERANT INPUTS AND OUTPUTS
HIGH SPEED:
tPD = 6.0 ns (MAX.) at VCC = 3V
POWER DOWN PROTECTION ON INPUTS
AND OUTPUTS
SYMMETRICAL OUTPUT IMPEDANCE:
|IOH| = IOL = 24mA (MIN) at VCC = 3V
PCI BUS LEVELS GUARANTEED AT 24 mA
BALANCED PROPAGATION DELAYS:
tPLH ≅ tPHL
OPERATING VOLTAGE RANGE:
VCC(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
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 C2MOS 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
September 2004
SOP
TSSOP
Table 1: Order Codes
PACKAGE
T&R
SOP
TSSOP
74LCX257MTR
74LCX257TTR
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.
Rev. 4
1/13
74LCX257
Figure 2: Input And Output Equivalent Circuit
Table 2: Pin Description
PIN N°
SYMBOL
1
2, 5, 11, 14
3, 6, 10, 13
4, 7, 9, 12
15
8
16
SELECT
1A to 4A
1B to 4B
1Y to 4Y
OE
GND
VCC
NAME AND FUNCTION
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
Table 3: Truth Table
INPUTS
OE
SELECT
A
B
Y
H
L
L
L
L
X
L
L
H
H
X
L
H
X
X
X
X
X
L
H
Z
L
H
L
H
X : Don’t Care
Z : High Impedance
2/13
OUTPUT
74LCX257
Figure 3: Logic Diagram
This logic diagram has not be used to estimate propagation delays
Table 4: Absolute Maximum Ratings
Symbol
Value
Unit
Supply Voltage
-0.5 to +7.0
V
VI
DC Input Voltage
-0.5 to +7.0
V
VO
DC Output Voltage (OFF State)
VO
DC Output Voltage (High or Low State) (note 1)
VCC
Parameter
IIK
DC Input Diode Current
IOK
DC Output Diode Current (note 2)
-0.5 to +7.0
V
-0.5 to VCC + 0.5
- 50
V
mA
- 50
mA
IO
DC Output Current
± 50
mA
ICC
DC Supply Current per Supply Pin
± 100
mA
IGND
DC Ground Current per Supply Pin
Tstg
Storage Temperature
TL
Lead Temperature (10 sec)
± 100
mA
-65 to +150
°C
300
°C
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is
not implied
1) IO absolute maximum rating must be observed
2) VO < GND
3/13
74LCX257
Table 5: Recommended Operating Conditions
Symbol
VCC
Parameter
Supply Voltage (note 1)
Value
Unit
2.0 to 3.6
V
VI
Input Voltage
0 to 5.5
V
VO
Output Voltage (OFF State)
0 to 5.5
V
VO
Output Voltage (High or Low State)
0 to VCC
V
± 24
mA
IOH, IOL
High or Low Level Output Current (VCC = 3.0 to 3.6V)
IOH, IOL
High or Low Level Output Current (VCC = 2.7V)
Top
dt/dv
Operating Temperature
Input Rise and Fall Time (note 2)
± 12
mA
-55 to 125
°C
0 to 10
ns/V
1) Truth Table guaranteed: 1.5V to 3.6V
2) VIN from 0.8V to 2V at VCC = 3.0V
Table 6: DC Specifications
Test Condition
Symbol
VIH
VIL
VOH
Parameter
High Level Input
Voltage
Low Level Input
Voltage
High Level Output
Voltage
Low Level Output
Voltage
Ioff
IOZ
ICC
∆ICC
4/13
Input Leakage
Current
Power Off Leakage
Current
High Impedance
Output Leakage
Current
Quiescent Supply
Current
ICC incr. per Input
Min.
Max.
2.0
-55 to 125 °C
Min.
Unit
Max.
2.0
V
2.7 to 3.6
0.8
0.8
2.7 to 3.6
IO=-100 µA
VCC-0.2
VCC-0.2
2.7
IO=-12 mA
2.2
2.2
IO=-18 mA
2.4
2.4
IO=-24 mA
2.2
2.7 to 3.6
V
V
2.2
IO=100 µA
0.2
0.2
IO=12 mA
0.4
0.4
IO=16 mA
0.4
0.4
IO=24 mA
0.55
0.55
2.7 to 3.6
VI = 0 to 5.5V
±5
±5
µA
0
VI or VO = 5.5V
10
10
µA
2.7 to 3.6
VI = VIH or VIL
VO = 0 to VCC
±5
±5
µA
2.7
3.0
II
-40 to 85 °C
VCC
(V)
3.0
VOL
Value
2.7 to 3.6
VI = VCC or GND
VI or VO= 3.6 to 5.5V
VIH = VCC - 0.6V
2.7 to 3.6
10
10
± 10
± 10
500
500
V
µA
µA
74LCX257
Table 7: Dynamic Switching Characteristics
Test Condition
Symbol
VOLP
VOLV
Parameter
Value
TA = 25 °C
VCC
(V)
Dynamic Low Level Quiet
Output (note 1)
Min.
Typ.
Max.
0.8
CL = 50pF
VIL = 0V, VIH = 3.3V
3.3
Unit
V
-0.8
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
tPLH tPHL
Propagation Delay
Time (A, B to Y)
tPLH tPHL
Propagation Delay
Time (SELECT to Y)
tPZL tPZH
Output Enable Time
tPLZ tPHZ
Output Disable Time
tOSLH
tOSHL
Output To Output
Skew Time (note1,
2)
VCC
(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
Value
CL
(pF)
RL
(Ω)
ts = tr
(ns)
50
500
2.5
50
500
2.5
50
500
2.5
50
500
2.5
50
500
2.5
-40 to 85 °C
-55 to 125 °C
Min.
Max.
Min.
Max.
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
6.5
6.0
8.5
7.0
8.5
7.0
6.0
5.5
1.0
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
6.5
6.0
8.5
7.0
8.5
7.0
6.0
5.5
1.0
Unit
ns
ns
ns
ns
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 switching in the same direction, either HIGH or LOW (tOSLH = | tPLHm - tPLHn|, tOSHL = | tPHLm - tPHLn|)
2) Parameter guaranteed by design
Table 9: Capacitive Characteristics
Test Condition
Symbol
CIN
COUT
CPD
Parameter
Value
TA = 25 °C
VCC
(V)
Min.
Typ.
Unit
Max.
Input Capacitance
3.3
VIN = 0 to VCC
7
pF
Output Capacitance
3.3
VIN = 0 to VCC
8
pF
Power Dissipation Capacitance
(note 1)
3.3
fIN = 10MHz
VIN = 0 or VCC
25
pF
1) CPD 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. ICC(opr) = CPD x VCC x fIN + ICC/4 (per
channel)
5/13
74LCX257
Figure 4: Test Circuit
TEST
SWITCH
tPLH, tPHL
Open
tPZL, tPLZ
6V
tPZH, tPHZ
GND
CL = 50 pF or equivalent (includes jig and probe capacitance)
RL = R1 = 500Ω or equivalent
RT = ZOUT of pulse generator (typically 50Ω)
Figure 5: Waveform - Propagation Delays (f=1MHz; 50% duty cycle)
6/13
74LCX257
Figure 6: Waveform - Output Enable And Disable Time (f=1MHz; 50% duty cycle)
7/13
74LCX257
SO-16 MECHANICAL DATA
DIM.
mm.
MIN.
TYP
A
a1
inch
MAX.
MIN.
TYP.
1.75
0.1
0.068
0.25
a2
MAX.
0.004
0.010
1.64
0.063
b
0.35
0.46
0.013
0.018
b1
0.19
0.25
0.007
0.010
C
0.5
0.019
c1
45° (typ.)
D
9.8
10
0.385
0.393
E
5.8
6.2
0.228
0.244
e
1.27
e3
0.050
8.89
0.350
F
3.8
4.0
0.149
0.157
G
4.6
5.3
0.181
0.208
L
0.5
1.27
0.019
0.050
M
S
0.62
0.024
8° (max.)
0016020D
8/13
74LCX257
TSSOP16 MECHANICAL DATA
mm.
inch
DIM.
MIN.
TYP
A
MAX.
MIN.
TYP.
MAX.
1.2
A1
0.05
A2
0.8
b
0.047
0.15
0.002
0.004
0.006
1.05
0.031
0.039
0.041
0.19
0.30
0.007
0.012
c
0.09
0.20
0.004
0.0079
D
4.9
5
5.1
0.193
0.197
0.201
E
6.2
6.4
6.6
0.244
0.252
0.260
E1
4.3
4.4
4.48
0.169
0.173
0.176
1
e
0.65 BSC
K
0˚
L
0.45
A
0.60
0.0256 BSC
8˚
0˚
0.75
0.018
8˚
0.024
0.030
A2
A1
b
e
K
c
L
E
D
E1
PIN 1 IDENTIFICATION
1
0080338D
9/13
74LCX257
Tape & Reel SO-16 MECHANICAL DATA
mm.
inch
DIM.
MIN.
A
MAX.
MIN.
330
13.2
TYP.
MAX.
12.992
C
12.8
D
20.2
0.795
N
60
2.362
T
10/13
TYP
0.504
22.4
0.519
0.882
Ao
6.45
6.65
0.254
0.262
Bo
10.3
10.5
0.406
0.414
Ko
2.1
2.3
0.082
0.090
Po
3.9
4.1
0.153
0.161
P
7.9
8.1
0.311
0.319
74LCX257
Tape & Reel TSSOP16 MECHANICAL DATA
mm.
inch
DIM.
MIN.
A
TYP
MAX.
MIN.
330
MAX.
12.992
C
12.8
D
20.2
0.795
N
60
2.362
T
13.2
TYP.
0.504
22.4
0.519
0.882
Ao
6.7
6.9
0.264
0.272
Bo
5.3
5.5
0.209
0.217
Ko
1.6
1.8
0.063
0.071
Po
3.9
4.1
0.153
0.161
P
7.9
8.1
0.311
0.319
11/13
74LCX257
Table 10: Revision History
Date
Revision
15-Sep-2004
4
12/13
Description of Changes
Ordering Codes Revision - pag. 1.
74LCX257
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences
of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted
by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject
to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not
authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.
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All other names are the property of their respective owners
© 2004 STMicroelectronics - All Rights Reserved
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13/13
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