CD74HC137, CD74HCT137,
CD54HC237, CD74HC237,
Data sheet acquired from Harris Semiconductor
SCHS146F
CD74HCT237
High-Speed CMOS Logic, 3- to 8-Line
Decoder/Demultiplexer with Address Latches
March 1998 - Revised October 2003
Both circuits have three binary select inputs (A0, A1 and A2)
that can be latched by an active High Latch Enable (LE)
signal to isolate the outputs from select-input changes. A
“Low” LE makes the output transparent to the input and the
circuit functions as a one-of-eight decoder. Two Output
Features
• Select One of Eight Data Outputs
- Active Low for CD74HC137 and CD74HCT137
- Active High for ’HC237 and CD74HCT237
[ /Title
(CD74
HC137
,
CD74
HCT13
7,
CD74
HC237
,
CD74
HCT23
7)
Enable inputs (OE and OE ) are provided to simplify
1
to
0
• l/O Port or Memory Selector
cascading
and
facilitate
demultiplexing.
The
demultiplexing function is accomplished by using the A , A ,
0
1
• Two Enable Inputs to Simplify Cascading
A inputs to select the desired output and using one of the
2
• Typical Propagation Delay of 13ns at V
o
= 5V,
other Output Enable inputs as the data input while holding
the other Output Enable input in its active state. In the
CD74HC137 and CD74HCT137 the selected output is a
“Low”; in the ’HC237 and CD74HCT237 the selected output is
a “High”.
CC
15pF, T = 25 C (CD74HC237)
A
• Fanout (Over Temperature Range)
- Standard Outputs. . . . . . . . . . . . . . . 10 LSTTL Loads
- Bus Driver Outputs . . . . . . . . . . . . . 15 LSTTL Loads
o
o
Ordering Information
• Wide Operating Temperature Range . . . -55 C to 125 C
• Balanced Propagation Delay and Transition Times
TEMP. RANGE
o
PART NUMBER
CD54HC237F3A
CD74HC137E
( C)
PACKAGE
16 Ld CERDIP
16 Ld PDIP
16 Ld TSSOP
16 Ld TSSOP
16 Ld TSSOP
16 Ld PDIP
16 Ld SOIC
16 Ld SOIC
16 Ld SOIC
16 Ld SOP
• Significant Power Reduction Compared to LSTTL
Logic ICs
-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
/Sub-
ject
(High
Speed
• HC Types
- 2V to 6V Operation
CD74HC137PW
CD74HC137PWR
CD74HC137PWT
CD74HC237E
- High Noise Immunity: N = 30%, N = 30%, of V
IL IH
CC
at V
= 5V
CC
• HCT Types
- 4.5V to 5.5V Operation
- Direct LSTTL Input Logic Compatibility,
V = 0.8V (Max), V = 2V (Min)
IL IH
CD74HC237M
- CMOS Input Compatibility, I ≤ 1µA at V , V
l
OL OH
CD74HC237MT
CD74HC237M96
CD74HC237NSR
CD74HC237PW
CD74HC237PWR
CD74HC237PWT
CD74HCT137E
CD74HCT137MT
CD74HCT137M96
CD74HCT237E
Description
The
CD74HC137,
CD74HCT137,
’HC237,
and
CD74HCT237 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.
16 Ld TSSOP
16 Ld TSSOP
16 Ld TSSOP
16 Ld PDIP
16 Ld SOIC
16 Ld SOIC
16 Ld PDIP
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.
CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures.
Copyright © 2003, Texas Instruments Incorporated
1