SGS Thomson Microelectronics 74LCX257TTR, 74LCX257MTR, 74LCX257M Datasheet

1/10June 2002

■ 5V TOLERANT INPUTS AND OUTPUTS

■ HIGH SPEED :

t

PD

= 6.0 ns (MAX.) at VCC = 3V

■ POWER DOWN PROTECTION ON INPUT S

AND OUTPUTS

■ SYMMETRICAL OUTPUT IMPEDANCE:

|I

OH

| = IOL = 24mA (MIN) at VCC = 3V

■ PCI BUS LEVELS GUARANT EED AT 2 4 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 v oltage 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 ou tputs.

It is composed of four independent 2 channel
multiplexers with commo n 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 "L ow", "A" dat a 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 stat ic discharge, giving
them 2KV ESD immunity and transient excess
voltage.

74LCX257

LOW VOLTAGE CMOS QUAD 2 CHANNEL MULTIPLEXER

WITH 5V TOLERANT IN PU TS AN D OU TPUTS (3-STATE)

PIN CONNECTION AND IEC LOGIC SYMBOLS

ORDER CODES

PACKAGE TUBE T & R

SOP 74LCX257M 74LCX257MTR

TSSOP 74LCX257TTR

TSSOPSOP

74LCX257

2/10

INPUT AND OUTPUT EQUIVALENT CIRCUIT

PIN DESCRIPTION

TRUTH TABLE

X : Don’t Care
Z : High Impedance

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

HXXXZ

LLLXL
LLHXH
LHXLL
LHXHH

74LCX257

3/10

LOGIC DIAGRAM

This log i c diagram has not be used to esti m ate propaga tion delays

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 ma xim um rating mu st 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 VCC + 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