1/13September 2004
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
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.
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.
74LCX257
LOW VOLTAGE CMOS QUAD 2 CHANNEL MULTIPLEXER
WITH 5V TOLERANT INPUTS AND OUTPUTS (3-STATE)
Figure 1: Pin Connection And IEC Logic Symbols
Table 1: Order Codes
PACKAGE T & R
SOP 74LCX257MTR
TSSOP 74LCX257TTR
TSSOPSOP
Rev. 4
74LCX257
2/13
Figure 2: Input And Output Equivalent Circuit
Table 2: Pin Description
Table 3: Truth Table
X : Don’t Care
Z : High Impedance
PIN N° 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
HXXXZ
LLLXL
LLHXH
LHXLL
LHXHH
74LCX257
3/13
Figure 3: Logic Diagram
This logic diagram has not be used to estimate propagation delays
Table 4: 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
1) I
O
absolute maximum rating must be observed
2) V
O
< GND
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 (OFF State)
-0.5 to +7.0 V
V
O
DC Output Voltage (High or Low State) (note 1) -0.5 to V
CC
+ 0.5
V
I
IK
DC Input Diode Current
- 50 mA
I
OK
DC Output Diode Current (note 2)
- 50 mA
I
O
DC Output Current
± 50 mA
I
CC
DC Supply Current per Supply Pin
± 100 mA
I
GND
DC Ground Current per Supply Pin
± 100 mA
T
stg
Storage Temperature
-65 to +150 °C
T
L
Lead Temperature (10 sec)
300 °C

74LCX257MTR

Mfr. #:
Manufacturer:
STMicroelectronics
Description:
Encoders, Decoders, Multiplexers & Demultiplexers Quad 2-Ch Multiplexr
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union

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