HD74BC374A
Octal D Type Flip Flops With 3 State Outputs
ADE-205-010A(Z)
Rev. 1
March 1993
Description
The HD74BC374A provides high drivability and operation equal to or better than high speed bipolar
standard logic IC by using Bi-CMOS process. The device features low power dissipation that is about 1/5
of high speed bipolar logic IC, when the frequency is 10 MHz. The device has eight edge triger D type flip
flop with three state outputs in a 20 pin package. Data at the D inputs meeting set up reguirements, are
transferred to the Q outputs on positive going transitions of the clock input. When the latch enable goes
low, data at the D inputs will be retained at the outputs until latch enable returns high again. When a high
logic level is applied to the output control input, all outputs go to a high impedance state, regardless of what
signals are present at the other inputs and the state of the storage elements.
Features
•
•
•
•
Input/Output are at high impedance state when power supply is off.
Built in input pull up circuit can make input pins be open, when not used.
TTL level input
Wide operating temperature range
Ta = –40 to + 85°C
Function Table
Inputs
G
H
L
L
L
H
L
X
Z
:
:
:
:
:
High level
Low level
Immaterial
High impedance
Low to high transition
CK
X
nD
X
L
H
X
Output
nQ
Z
L
H
No change
HD74BC374A
Pin Arrangement
G
1Q
1D
2D
2Q
3Q
3D
4D
4Q
GND
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
V
CC
8Q
8D
7D
7Q
6Q
6D
5D
5Q
CK
(Top view)
Absolute Maximum Ratings
Item
Supply voltage
Input diode current
Input voltage
Output voltage
Off state output voltage
Storage temperature
Note:
Symbol
V
CC
I
IK
V
IN
V
OUT
V
OUT(off)
Tstg
Rating
–0.5 to +7.0
±30
–0.5 to +7.5
–0.5 to +7.5
–0.5 to +5.5
–65 to +150
Unit
V
mA
V
V
V
°C
1. The absolute maximum ratings are values which must not individually be exceeded, and
furthermore, no two of which may be realized at the same time.
2
HD74BC374A
Recommended Operating Conditions
Item
Supply voltage
Input voltage
Output voltage
Operating temperature
Input rise/fall time*
1
Note:
Symbol
V
CC
V
IN
V
OUT
Topr
t
r
, t
f
Min
4.5
0
0
–40
0
Typ
5.0
—
—
—
—
Max
5.5
V
CC
V
CC
85
8
Unit
V
V
V
°C
ns/V
1. This item guarantees maximum limit when one input switches.
Waveform: Refer to test circuit of switching characteristics.
Logic Diaglam
G
1D
D
Q
CK
D
Q
CK
D
Q
CK
D
Q
CK
1Q
2D
2Q
3D
3Q
4D
4Q
8D
CK
D
Q
CK
8Q
3
HD74BC374A
Electrical Characteristics
(Ta = –40°C to +85°C)
Item
Input voltage
Symbol
V
IH
V
IL
Output voltage
V
OH
4.5
4.5
V
OL
4.5
4.5
Input diode voltage
Input current
V
IK
I
I
4.5
5.5
5.5
5.5
Short circuit output current*
1
Off state output current
I
OS
I
OZH
I
OZL
Supply current
I
CCL
I
CCH
I
CCZ
I
CCT
*
2
5.5
5.5
5.5
5.5
5.5
5.5
5.5
V
CC
(V)
Min
2.0
—
2.4
2.0
—
—
—
—
—
—
–100
—
—
—
—
—
—
Max
—
0.8
—
—
0.4
0.5
–1.2
1.0
–250
100
–225
50
–50
29.5
2.5
2.5
1.5
Unit
V
V
V
V
V
V
V
µA
µA
µA
mA
µA
µA
mA
mA
mA
mA
I
OH
= –3 mA
I
OH
= –15 mA
I
OL
= 24 mA
I
OL
= 48 mA
I
IN
= –18 mA
V
IN
= 5.5 V
V
IN
= 0 V
V
IN
= 7.0 V
V
IN
= 0 or 5.5 V
V
O
= 2.7 V
V
O
= 0.5 V
V
IN
= 0 or 5.5 V
All output is “L”
V
IN
= 0 or 5.5 V
All output is “H”
V
IN
= 0 or 5.5 V
All output is “Z”
V
IN
= 3.4 or 0.5 V
Test Conditions
Notes : 1. Not more than one output should be shorted at a time and duration of the short circuit should not
exceed one second.
2. When input by the TTL level, it shows I
CC
increase at per one input pin.
4
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