CD74HC259,
CD74HCT259
Data sheet acquired from Harris Semiconductor
SCHS173
High Speed CMOS Logic
8-Bit Addressable Latch
November 1997
Features
Description
• Buffered Inputs and Outputs
• Four Operating Modes
• Typical Propagation Delay of 15ns at V
The Harris CD74HC259 and CD74HCT259 Addressable
Latch features the low-power consumption associated with
CMOS circuitry and has speeds comparable to low-power
Schottky.
[ /Title
(CD74
HC259
,
CD74
HCT25
9)
= 5V,
CC
o
C = 15pF, T = 25 C
L
A
This latches three active modes and one reset mode. When
both the Latch Enable (LE) and Master Reset (MR) inputs are
low (8-line Demultiplexer mode) the output of the addressed
latch follows the Data input and all other outputs are forced
low. When both MR and LE are high (Memory Mode), all
• Fanout (Over Temperature Range)
- Standard Outputs. . . . . . . . . . . . . . . 10 LSTTL Loads
- Bus Driver Outputs . . . . . . . . . . . . . 15 LSTTL Loads
o
o
• Wide Operating Temperature Range . . . -55 C to 125 C outputs are isolated from the Data input, i.e., all latches hold
the last data presented before the LE transition from low to
high. A condition of LE low and MR high (Addressable Latch
mode) allows the addressed latch’s output to follow the data
input; all other latches are unaffected. The Reset mode (all
outputs low) results when LE is high and MR is low.
/Sub-
ject
• Balanced Propagation Delay and Transition Times
• Significant Power Reduction Compared to LSTTL
Logic ICs
(High
Speed
CMOS
Logic
8-Bit
Addres
sable
Latch)
• HC Types
- 2V to 6V Operation
Ordering Information
- High Noise Immunity: N = 30%, N = 30% of V
IL IH CC
at V
= 5V
PKG.
CC
o
PART NUMBER TEMP. RANGE ( C) PACKAGE
NO.
E16.3
E16.3
• HCT Types
CD74HC259E
CD74HCT259E
CD74HC259M
CD74HCT259M
NOTES:
-55 to 125
-55 to 125
-55 to 125
-55 to 125
16 Ld PDIP
16 Ld PDIP
- 4.5V to 5.5V Operation
- Direct LSTTL Input Logic Compatibility,
V = 0.8V (Max), V = 2V (Min)
IL IH
16 Ld SOIC M16.15
16 Ld SOIC M16.15
- CMOS Input Compatibility, I ≤ 1µA at V , V
OL OH
l
1. When ordering, use the entire part number. Add the suffix 96 to
obtain the variant in the tape and reel.
2. Wafer or die for this part number is available which meets all elec-
trical specifications. Please contact your local sales office or
Harris customer service for ordering information.
Pinout
CD74HC259, CD74HCT259
(PDIP, SOIC)
TOP VIEW
A0
A1
1
2
3
4
5
6
7
8
16 V
CC
15 MR
14 LE
13 D
A2
Q0
Q1
12 Q7
11 Q6
10 Q5
Q2
Q3
9
Q4
GND
CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures.
File Number 1727.1
Copyright © Harris Corporation 1997
1