CD54/74HC138, CD54/74HCT138,
CD54/74HC238, CD54/74HCT238
Data sheet acquired from Harris Semiconductor
SCHS147I
High-Speed CMOS Logic 3- to 8-Line Decoder/
Demultiplexer Inverting and Noninverting
October 1997 - Revised August 2004
Features
Ordering Information
• Select One Of Eight Data Outputs
Active Low for 138, Active High for 238
TEMP. RANGE
o
PART NUMBER
CD54HC138F3A
CD54HC238F3A
CD54HCT138F3A
CD54HCT238F3A
CD74HC138E
( C)
PACKAGE
16 Ld CERDIP
16 Ld CERDIP
16 Ld CERDIP
16 Ld CERDIP
16 Ld PDIP
16 Ld SOIC
16 Ld SOIC
16 Ld SOIC
16 Ld PDIP
16 Ld SOIC
16 Ld SOIC
16 Ld SOIC
16 Ld SOP
[ /Title
(CD74
HC138
,
CD74
HCT13
8,
CD74
HC238
,
CD74
HCT23
8)
• l/O Port or Memory Selector
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
• Three Enable Inputs to Simplify Cascading
• Typical Propagation Delay of 13 ns at V
CC
= 5 V,
o
C = 15 pF, T = 25 C
L
A
• Fanout (Over Temperature Range)
- Standard Outputs. . . . . . . . . . . . . . . 10 LSTTL Loads
- Bus Driver Outputs . . . . . . . . . . . . . 15 LSTTL Loads
CD74HC138M
o
o
• Wide Operating Temperature Range . . . -55 C to 125 C
• Balanced Propagation Delay and Transition Times
CD74HC138MT
CD74HC138M96
CD74HC238E
• Significant Power Reduction Compared to LSTTL
Logic ICs
• HC Types
CD74HC238M
/Sub-
ject
(High
Speed
- 2 V to 6 V Operation
CD74HC238MT
CD74HC238M96
CD74HC238NSR
CD74HC238PW
CD74HC238PWR
CD74HC238PWT
CD74HCT138E
CD74HCT138M
CD74HCT138MT
CD74HCT138M96
CD74HCT238E
CD74HCT238M
CD74HCT238M96
- High Noise Immunity: N = 30%, N = 30% of V
IL IH CC
at V
= 5 V
CC
• HCT Types
- 4.5-V to 5.5-V Operation
16 Ld TSSOP
16 Ld TSSOP
16 Ld TSSOP
16 Ld PDIP
16 Ld SOIC
16 Ld SOIC
16 Ld SOIC
16 Ld PDIP
16 Ld SOIC
16 Ld SOIC
- Direct LSTTL Input Logic Compatibility,
V = 0.8 V (Max), V = 2 V (Min)
IL
IH
- CMOS Input Compatibility, I ≤ 1µA at V , V
OL OH
l
Description
The ’HC138, ’HC238, ’HCT138, and ’HCT238 are high-speed
silicon-gate CMOS decoders well suited to memory address
decoding or data-routing applications. Both circuits feature
low power consumption usually associated with CMOS
circuitry, yet have speeds comparable to low-power Schottky
TTL logic. Both circuits have three binary select inputs (A0,
A1, and A2). If the device is enabled, these inputs determine
which one of the eight normally high outputs of the
HC/HCT138 series go low or which of the normally low
outputs of the HC/HCT238 series go high.
NOTE: When ordering, use the entire part number. The suffixes 96
and R denote tape and reel. The suffix T denotes a small-quantity
reel of 250.
Two active low and one active high enables (E1, E2, and E3)
are provided to ease the cascading of decoders. The
decoder’s eight outputs can drive ten low-power Schottky
TTL equivalent loads.
CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures.
Copyright © 2004, Texas Instruments Incorporated
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