鈥?/div>
IDT54/74FCT138 equivalent to FAST鈩?speed
IDT54/74FCT138A 35% faster than FAST
IDT54/74FCT138C 40% faster than FAST
Equivalent to FAST speeds output drive over full tem-
perature and voltage supply extremes
I
OL
= 48mA (commercial) and 32mA (military)
CMOS power levels (1mW typ. static)
TTL input and output level compatible
CMOS output level compatible
Substantially lower input current levels than FAST
(5碌A max.)
JEDEC standard pinout for DIP and LCC
Product available in Radiation Tolerant and Radiation
Enhanced versions
Military product compliant to MIL-STD-883, Class B
Standard Military Drawing # 5962-87654 is listed on this
function. Refer to section 2.
The IDT54/74FCT138/A/C are 1-of-8 decoders built using
an advanced dual metal CMOS technology. The IDT54/
74FCT138/A/C accept three binary weighted inputs (A
0
, A
1
,
A
2
) and, when enabled, provide eight mutually exclusive
active LOW outputs (
O
0
-
O
7
). The IDT54/74FCT138/A/C
feature three enable inputs, two active LOW (
E
1
,
E
2
) and one
active HIGH (E
3
). All outputs will be HIGH unless
E
1
and
E
2
are LOW and E
3
is HIGH. This multiple enable function allows
easy parallel expansion of the device to a 1-of-32 (5 lines to
32 lines) decoder with just four IDT54/74FCT138/A/C devices
and one inverter.
FUNCTIONAL BLOCK DIAGRAM
A
2
A
1
A
0
E
1
E
2
E
3
PIN CONFIGURATIONS
A
0
A
1
A
2
E
1
E
2
E
3
O
7
GND
1
2
3
4
5
6
7
8
16
15
P16-1,
D16-1,
&
E16-1
14
13
12
11
10
9
Vcc
O
0
O
1
O
2
O
3
O
4
O
5
O
6
DIP/SOIC/CERPACK
TOP VIEW
INDEX
O
7
O
6
O
5
O
4
O
3
O
2
O
1
O
0
2581 drw 02
A
2
E
1
NC
E
2
E
3
A
1
A
0
NC
Vcc
O
0
3
4
5
6
7
8
2
20 19
18
1
17
16
15
14
9 10 11 12 13
L20-2
O
1
O
2
NC
O
3
O
4
2581 drw 01
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
FAST is a trademark of National Semiconductor Co.
MILITARY AND COMMERCIAL TEMPERATURE RANGES
漏1992
Integrated Device Technology, Inc.
O
7
GND
NC
O
6
O
5
LCC
TOP VIEW
MAY 1992
DSC-4625/3
7.3
1
1
2
3
4
5
6
