74HCT257N NXP Semiconductors, 74HCT257N Datasheet - Page 2

• Manufacturer Part Number: 74HCT257N
• Description: IC, 74HCT CMOS, 74HCT257, DIP16, 5V
• Manufacturer: NXP Semiconductors

Specifications of 74HCT257N

• Logic Type: Multiplexer
• No. Of Outputs: 4
• Supply Voltage Range: 4.5V To 5.5V
• Logic Case Style: DIP
• No. Of Pins: 16
• Operating Temperature Range: -40°C To +125°C
• Svhc: No SVHC (18-Jun-2010)
• Package: RoHS Compliant
• Base Number: 74
• Rohs Compliant: Yes

Philips Semiconductors
FEATURES
GENERAL DESCRIPTION
The 74HC/HCT257 are high-speed Si-gate CMOS devices
and are pin compatible with low power Schottky TTL
(LSTTL). They are specified in compliance with JEDEC
standard no. 7A.
The 74HC/HCT257 have four identical 2-input multiplexers
with 3-state outputs, which select 4 bits of data from two
sources and are controlled by a common data select
input (S).
QUICK REFERENCE DATA
GND = 0 V; T
Notes
1. C
2. For HC the condition is V
1998 Sep 30
SYMBOL
t
C
C
PHL
Non-inverting data path
3-state outputs interface directly with system bus
Output capability: bus driver
I
I
PD
Quad 2-input multiplexer; 3-state
CC
f
f
C
V
For HCT the condition is V
i
o
/ t
CC
PD
= input frequency in MHz
L
category: MSI
= output frequency in MHz
(C
PLH
= output load capacitance in pF
P
= supply voltage in V
is used to determine the dynamic power dissipation (P
L
D
= C
V
CC
amb
PD
2
PARAMETER
propagation delay
input capacitance
power dissipation capacitance per multiplexer notes 1 and 2
= 25 C; t
V
f
nI
S to nY
o
CC
) = sum of outputs
0
, nI
2
1
f
r
i
to nY
= t
I
I
f
= GND to V
= GND to V
= 6 ns
(C
L
V
CC
2
CC
CC
f
o
) where:
1.5 V
2
The data inputs from source 0 (1I
when input S is LOW and the data inputs from source 1
(1I
the outputs (1Y to 4Y) in true (non-inverting) form from the
selected inputs.
The “257” is the logic implementation of a 4-pole,
2-position switch, where the position of the switch is
determined by the logic levels applied to S. The outputs
are forced to a high impedance OFF-state when OE is
HIGH.
The logic equations for the outputs are:
1Y = OE.(1I
2Y = OE.(2I
3Y = OE.(3I
4Y = OE.(4I
The “257” is identical to the “258” but has non-inverting
(true) outputs.
D
1
in W):
to 4I
CONDITIONS
C
L
= 15 pF; V
1
) are selected when S is HIGH. Data appears at
1
1
1
1
.S 1I
.S 2I
.S 3I
.S 4I
CC
0
0
0
0
.S)
.S)
.S)
.S)
= 5 V
11
14
3.5
45
HC
TYPICAL
74HC/HCT257
0
Product specification
to 4I
13
17
3.5
45
0
HCT
) are selected
ns
ns
pF
pF
UNIT