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SN54HCT574, SN74HCT574
OCTAL EDGE-TRIGGERED D-TYPE FLIP-FLOPS
WITH 3-STATE OUTPUTS
SCLS177C – MARCH 1984 – REVISED MA Y 1997
D
Inputs Are TTL-Voltage Compatible
D
High-Current 3-State Noninverting Outputs
Drive Bus Lines Directly or up to 15 LSTTL
Loads
D
Bus-Structured Pinout
D
Package Options Include Plastic
Small-Outline (DW), Thin Shrink
Small-Outline (PW), and Ceramic Flat (W)
Packages, Ceramic Chip Carriers (FK), and
Standard Plastic (N) and Ceramic (J)
300-mil DIPs
description
These octal edge-triggered D-type flip-flops
feature 3-state outputs designed specifically for
bus driving. They are particularly suitable for
implementing buffer registers, I/O ports,
bidirectional bus drivers, and working registers.
The eight flip-flops enter data on the low-to-high
transition of the clock (CLK) input.
A buffered output-enable (OE) input can be used
to place the eight outputs in either a normal logic
state (high or low logic levels) or the
high-impedance state. In the high-impedance
state, the outputs neither load nor drive the bus
lines significantly. The high-impedance state and
increased drive provide the capability to drive bus
lines without interface or pullup components.
SN54HCT574 ...J OR W PACKAGE
SN74HCT574 ...DW, N, OR PW PACKAGE
SN54HCT574 . . . FK PACKAGE
3D
4D
5D
6D
7D
(TOP VIEW)
OE
1
1D
2
2D
3
3D
4
4D
5
5D
6
6D
7
7D
8
8D
9
GND
10
(TOP VIEW)
2D1DOE
3212019
4
5
6
7
8
910111213
8D
GND
20
19
18
17
16
15
14
13
12
11
CLK
CC
V
8Q
V
1Q
2Q
3Q
4Q
5Q
6Q
7Q
8Q
CLK
1Q
18
17
16
15
14
7Q
CC
2Q
3Q
4Q
5Q
6Q
OE
does not affect the internal operations of the flip-flops. Old data can be retained or new data can be entered
while the outputs are in the high-impedance state.
The SN54HCT574 is characterized for operation over the full military temperature range of –55°C to 125°C. The
SN74HCT574 is characterized for operation from –40°C to 85°C.
FUNCTION TABLE
(each flip-flop)
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.
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.
INPUTS
OE CLK D
L ↑ H H
L ↑ LL
L H or L X Q
H X X Z
OUTPUT
Q
0
Copyright 1997, Texas Instruments Incorporated
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
1
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SN54HCT574, SN74HCT574
OCTAL EDGE-TRIGGERED D-TYPE FLIP-FLOPS
WITH 3-STATE OUTPUTS
SCLS177C – MARCH 1984 – REVISED MA Y 1997
logic symbol
†
This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.
†
OE
CLK
1D
2D
3D
4D
5D
6D
7D
8D
1
11
2
3
4
5
6
7
8
9
EN
C1
1D
logic diagram (positive logic)
1
OE
11
CLK
C1
1D
2
1D
19
18
17
16
15
14
13
12
1Q
2Q
3Q
4Q
5Q
6Q
7Q
8Q
19
1Q
To Seven Other Channels
absolute maximum ratings over operating free-air temperature range
‡
Supply voltage range, VCC –0.5 V to 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input clamp current, IIK (VI < 0 or VI > VCC) (see Note 1) ±20 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output clamp current, IOK (VO < 0 or VO > VCC) (see Note 1) ±20 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Continuous output current, IO (VO = 0 to VCC) ±35 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Continuous current through V
Package thermal impedance, θ
or GND ±70 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CC
(see Note 2): DW package 97°C/W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
JA
N package 67°C/W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PW package 128°C/W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage temperature range, T
‡
Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
NOTES: 1. The input and output voltage ratings may be exceeded if the input and output current ratings are observed.
2. The package thermal impedance is calculated in accordance with JESD 51, except for through-hole packages, which use a trace
length of zero.
–65°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
stg
2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265