SN54HCT574, SN74HCT574
OCTAL EDGE-TRIGGERED D-TYPE FLIP-FLOPS
WITH 3-STATE OUTPUTS
SCLS177C – MARCH 1984 – REVISED MAY 1997
SN54HCT574 . . . J OR W PACKAGE
SN74HCT574 . . . DW, N, OR PW PACKAGE
(TOP VIEW)
Inputs Are TTL-Voltage Compatible
High-Current 3-State Noninverting Outputs
Drive Bus Lines Directly or up to 15 LSTTL
Loads
OE
1D
2D
3D
4D
5D
6D
7D
8D
V
CC
1Q
2Q
1
2
3
4
5
6
7
8
9
20
19
18
Bus-Structured Pinout
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
17 3Q
16 4Q
15 5Q
14 6Q
13
7Q
12 8Q
description
GND 10
11 CLK
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.
SN54HCT574 . . . FK PACKAGE
(TOP VIEW)
3
2
1
20 19
18
The eight flip-flops enter data on the low-to-high
transition of the clock (CLK) input.
2Q
3Q
4Q
3D
4D
5D
6D
7D
4
5
6
7
8
17
16
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.
15 5Q
14
9 10 11 12 13
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)
INPUTS
OUTPUT
Q
OE
L
CLK
D
H
L
↑
↑
H
L
L
L
H or L
X
X
X
Q
0
H
Z
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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