IDT54/74FCT157T/AT/CT/DT
IDT54/74FCT257T/AT/CT/DT
IDT54/74FCT2257T/AT/CT
FAST CMOS
QUAD 2-INPUT
MULTIPLEXER
Integrated Device Technology, Inc.
DESCRIPTION:
FEATURES:
The FCT157T, FCT257T/FCT2257T are high-speed quad
2-inputmultiplexersbuiltusinganadvanceddualmetalCMOS
technology. Four bits of data from two sources can be
selected using the common select input. The four buffered
outputs present the selected data in the true (non-inverting)
form.
• Common features:
– Low input and output leakage ≤1µA (max.)
– CMOS power levels
– True TTL input and output compatibility
– VOH = 3.3V (typ.)
– VOL = 0.3V (typ.)
The FCT157T has a common, active-LOW, enable input.
When the enable input is not active, all four outputs are held
LOW. A common application of ‘FCT157T is to move data
from two different groups of registers to a common bus.
Another application is as a function generator. The ‘FCT157T
can generate any four of the 16 different functions of two
variables with one variable common.
– Meets or exceeds JEDEC standard 18 specifications
– Product available in Radiation Tolerant and Radiation
Enhanced versions
– Military product compliant to MIL-STD-883, Class B
and DESC listed (dual marked)
– Available in DIP, SOIC, SSOP, QSOP, CERPACK
and LCC packages
The FCT257T/FCT2257T have a common Output Enable
(OE) input. When OE is HIGH, all outputs are switched to a
high-impedancestateallowingtheoutputstointerfacedirectly
with bus-oriented systems.
• Features for FCT157T/257T:
– Std., A, C and D speed grades
– High drive outputs (-15mA IOH, 48mA IOL)
• Features for FCT2257T:
The FCT2257T has balanced output drive with current
limiting resistors. This offers low ground bounce, minimal
undershoot and controlled output fall times-reducing the need
for external series terminating resistors. FCT2xxxT parts are
plug-in replacements for FCTxxxT parts.
– Std., A, and C speed grades
– Resistor outputs (-15mA IOH, 12mA IOL Com.)
(-12mA IOH, 12mA IOL Mil.)
– Reduced system switching noise
FUNCTIONAL BLOCK DIAGRAM
PIN CONFIGURATIONS
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
S
I0A
Vcc
E or OE*
I0C
I1C
S
P16-1,
D16-1,
SO16-1,
SO16-7
&
1A
I
Z
A
157 Only
E
Z
C
I
I
0B
1B
3 other multiplexers
I0D
E16-1
I
1D
Z
B
1B 1D
I
Z
D
–I
GND
Z B–Z D
2537 drw 02
DIP/SOIC/QSOP/CERPACK
TOP VIEW
0B 0D
I
–I
1A
I
A
Z
INDEX
0A
I
3
2
20 19
18
1A
I
4
5
6
7
8
I0C
I1C
NC
ZC
I0D
1
257 Only OE
ZA
NC
I0B
I1B
17
16
15
14
L20-2
2537 drw 01
10 11 12 13
9
LCC
2537 drw 03
TOP VIEW
* E for FCT157, OE for FCT257/FCT2257.
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
MILITARY AND COMMERCIAL TEMPERATURE RANGES
JUNE 1996
1996 Integrated Device Technology, Inc.
6.6
2537/6
1
IDT [ INTEGRATED DEVICE TECHNOLOGY ]
