1/11April 2001
a73 HIGH SPEED: t
PD
= 4.5ns (TYP.) at V
CC
= 5V
a73 LOW POWER DISSIPATION:
I
CC
= 4µA(MAX.) at T
A
=25°C
a73 HIGH NOISE IMMUNITY:
V
NIH
= V
NIL
= 28 % V
CC
(MIN.)
a73 50Ω TRANSMISSION LINE DRIVING
CAPABILITY
a73 SYMMETRICAL OUTPUT IMPEDANCE:
|I
OH
| = I
OL
= 24mA (MIN)
a73 BALANCED PROPAGATION DELAYS:
t
PLH
≅ t
PHL

a73 OPERATING VOLTAGE RANGE:
V
CC
(OPR) = 2V to 6V
a73 PIN AND FUNCTION COMPATIBLE WITH
74 SERIES 257
a73 IMPROVED LATCH-UP IMMUNITY
DESCRIPTION
The 74AC257 is an advanced high-speed CMOS
QUAD 2-CHANNEL MULTIPLEXER (3-STATE)
fabricated with sub-micron silicon gate and
double-layer metal wiring C
2
MOS tecnology.
It is composed of four independent 2-channel
multiplexer with common SELECT and ENABLE
(OE) inputs. It is a non-inverting multiplexer. When
the OE input is held HIGH,all the output become in
high impedance state. If SELECT input is held
LOW, "A" data is selected, when SELECT input is
held HIGH, "B" data is chosen.
All inputs and outputs are equipped with
protection circuits against static discharge, giving
them 2KV ESD immunity and transient excess
voltage.
74AC257
QUAD 2 CHANNEL MULTIPLEXER (3-STATE)

PIN CONNECTION AND IEC LOGIC SYMBOLS
ORDER CODES
PACKAGE TUBE T & R
DIP 74AC257B
SOP 74AC257M 74AC257MTR
TSSOP 74AC257TTR
TSSOPDIP SOP