SN54HCT74, SN74HCT74
DUAL D-TYPE POSITIVE-EDGE-TRIGGERED FLIP-FLOPS
WITH CLEAR AND PRESET
SCLS169B – DECEMBER 1982 – REVISED MAY 1997
SN54HCT74 . . . J OR W PACKAGE
SN74HCT74 . . . D, N, OR PW PACKAGE
(TOP VIEW)
Inputs Are TTL-Voltage Compatible
Package Options Include Plastic
Small-Outline (D), Thin Shrink
Small-Outline (PW), and Ceramic Flat (W)
Packages, Ceramic Chip Carriers (FK), and
Standard Plastic (N) and Ceramic (J)
300-mil DIPs
1CLR
1D
V
CC
2CLR
2D
1
2
3
4
5
6
7
14
13
12
11
1CLK
1PRE
1Q
2CLK
10 2PRE
description
9
8
1Q
2Q
2Q
The ’HCT74 contain two independent D-type
positive-edge-triggered flip-flops. A low level at
the preset (PRE) or clear (CLR) inputs sets or
resets the outputs regardless of the levels of the
other inputs. When PRE and CLR are inactive
(high), data at the data (D) input meeting the setup
time requirements are transferred to the outputs
on the positive-going edge of the clock (CLK)
pulse. Clock triggering occurs at a voltage level
and is not directly related to the rise time of CLK.
Following the hold-time interval, data at the
D input may be changed without affecting the
levels at the outputs.
GND
SN54HCT74 . . . FK PACKAGE
(TOP VIEW)
3
2
1
20 19
18
2D
1CLK
NC
4
5
6
7
8
NC
17
16
2CLK
1PRE
NC
15 NC
14
9 10 11 12 13
2PRE
1Q
The SN54HCT74 is characterized for operation
over the full military temperature range of –55°C
to 125°C. The SN74HCT74 is characterized for
operation from –40°C to 85°C.
NC – No internal connection
FUNCTION TABLE
INPUTS
OUTPUT
PRE
L
CLR
CLK
X
D
X
X
X
H
L
Q
H
L
Q
L
H
L
H
X
H
†
†
H
L
L
X
H
H
H
H
H
H
L
L
H
H
H
L
X
Q
Q
0
0
†
This configuration is unstable; that is, it does not
persist when PRE or CLR returns to its inactive
(high) level.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
Copyright 1997, Texas Instruments Incorporated
UNLESS OTHERWISE NOTED this document contains PRODUCTION
DATA information current as of publication date. Products conform to
specifications per the terms of Texas Instruments standard warranty.
Production processing does not necessarily include testing of all
parameters.
1
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