Fairchild DM74ALS874B Dual 4-bit d-type edge-triggered flip-flop with 3-state output Datasheet

Revised July 2001
DM74ALS874B
Dual 4-Bit D-Type Edge-Triggered Flip-Flop
with 3-STATE Outputs
General Description
Features
This dual 4-bit register features totem-pole 3-STATE outputs designed specifically for driving highly-capacitive or
relatively low-impedance loads. The high-impedance state
and increased high-logic-level drive provide this register
with the capability of being connected directly to and driving the bus lines in a bus-organized system without need
for interface or pull-up components. It is particularly attractive for implementing buffer registers, I/O ports, bidirectional bus drivers, and working registers.
■ Switching specifications at 50 pF
■ Switching specifications guaranteed over full temperature and VCC range
■ Advanced oxide-isolated, ion-implanted Schottky TTL
process
■ 3-STATE buffer-type outputs drive bus lines directly
■ Space saving 300 mil wide package
■ Asynchronous clear
The eight flip-flops of the DM74ALS874B are edge-triggered D-type flip-flops. On the positive transition of the
clock, the Q outputs will be set to the logic states that were
set up at the D inputs.
A buffered output control input can be used to place the
eight outputs in either a normal logic state (HIGH or LOW
logic levels) or a high-impedance state. In the high-impedance state the outputs neither load nor drive the bus lines
significantly.
The output control does not affect the internal operation of
the flip-flops. That is, the old data can be retained or new
data can be entered even while the outputs are OFF.
Ordering Code:
Order Number
Package Number
DM74ALS874BWM
M24B
24-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
Package Description
DM74ALS874BNT
N24C
24-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" Wide
Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Connection Diagram
© 2001 Fairchild Semiconductor Corporation
DS006244
www.fairchildsemi.com
DM74ALS874B Dual 4-Bit D-Type Edge-Triggered Flip-Flop with 3-STATE Outputs
April 1984
DM74ALS874B
Function Table
Logic Diagram
Inputs
Output
CLR
D
CLK
OC
Q
X
X
X
H
Z
L
X
X
L
L
H
H
↑
L
H
H
L
↑
L
L
H
X
L
L
Q0
L = LOW State
H = HIGH State
X = Don’t Care
↑ = Positive Edge Transition
Z = High Impedance State
Q0 = Previous Condition of Q
www.fairchildsemi.com
2
Supply Voltage
7V
Input Voltage
7V
Voltage Applied to Disabled Output
5.5V
Note 1: The “Absolute Maximum Ratings” are those values beyond which
the safety of the device cannot be guaranteed. The device should not be
operated at these limits. The parametric values defined in the Electrical
Characteristics tables are not guaranteed at the absolute maximum ratings.
The “Recommended Operating Conditions” table will define the conditions
for actual device operation.
0°C to +70°C
Operating Free Air Temperature Range
−65°C to +150°C
Storage Temperature Range
Typical θJA
N Package
51.0°C/W
M Package
86.5°C/W
Recommended Operating Conditions
Symbol
Parameter
Min
Nom
Max
4.5
5
5.5
Units
VCC
Supply Voltage
VIH
HIGH Level Input Voltage
VIL
LOW Level Input Voltage
0.8
V
IOH
HIGH Level Output Current
−2.6
mA
IOL
LOW Level Output Current
fCLK
Clock Frequency
tWCLK
Width of Clock Pulse
V
2
0
V
24
mA
30
MHz
HIGH
16.5
ns
LOW
16.5
ns
tWCLR
Width of Clear Pulse
10
ns
tSU
Data Setup Time (Note 2)
LOW
15↑
ns
tH
Data Hold Time (Note 2)
0↑
ns
tSU
Clear Inactive
12
ns
TA
Free Air Operating Temperature
0
70
°C
Note 2: The (↑) arrow indicates the positive edge of the Clock is used for reference.
3
www.fairchildsemi.com
DM74ALS874B
Absolute Maximum Ratings(Note 1)
DM74ALS874B
Electrical Characteristics
over recommended operating free air temperature range. All typical values are measured at VCC = 5V, TA = 25°C.
Symbol
Parameter
Conditions
Min
Typ
Max
Units
−1.2
V
VIK
Input Clamp Voltage
VCC = 4.5V, II = −18 mA
VOH
HIGH Level
VCC = 4.5V
Output Voltage
VIL = VIL Max
VOL
IOH = Max
VCC = 4.5V to 5.5V
IOH = −400 µA
LOW Level
VCC = 4.5V
IOL = 12 mA
Output Voltage
VIH = 2V
Input Current @ Maximum
VCC = 5.5V, VIH = 7V
2.4
V
VCC − 2
IOL = 24 mA
II
3.2
V
0.25
0.4
V
0.35
0.5
V
0.1
mA
Input Voltage
IIH
HIGH Level Input Current
VCC = 5.5V, VIH = 2.7V
20
µA
IIL
LOW Level Input Current
VCC = 5.5V, VIL = 0.4V
−0.2
mA
IO
Output Drive Current
VCC = 5.5V, VO = 2.25V
−112
mA
IOZH
OFF-State Output Current
VCC = 5.5V, VIH = 2V
HIGH Level Voltage Applied
VO = 2.7V
20
µA
−20
µA
IOZL
ICC
−30
OFF-State Output Current
VCC = 5.5V, VIH = 2V
LOW Level Voltage Applied
VO = 0.4V
Supply Current
VCC = 5.5V
Outputs HIGH
14
21
mA
Outputs OPEN
Outputs LOW
19
30
mA
Outputs Disabled
20
32
mA
Min
Max
Units
30
MHz
Switching Characteristics
over recommended operating free air temperature range.
Symbol
Parameter
Maximum Clock Frequency
tPLH
Propagation Delay Time
RL = 500,Ω,
LOW-to-HIGH Level Output
CL = 50 pF
tPHL
Conditions
Propagation Delay Time
HIGH-to-LOW Level Output
tPZH
tPZL
tPHZ
tPLZ
tPHL
From
Clock
Any Q
4
14
ns
Clock
Any Q
4
14
ns
Any Q
4
18
ns
Any Q
4
18
ns
Any Q
2
10
ns
Any Q
3
12
ns
Any Q
5
17
ns
Output Enable Time
Output
to HIGH Level Output
Control
Output Enable Time
Output
to LOW Level Output
Control
Output Disable Time
Output
from HIGH Level Output
Control
Output Disable Time
Output
from LOW Level Output
Control
Propagation Delay Time
Clear
HIGH-to-LOW Level Output
www.fairchildsemi.com
To
VCC = 4.5V to 5.5V
fMAX
4
DM74ALS874B
Physical Dimensions inches (millimeters) unless otherwise noted
24-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
Package Number M24B
5
www.fairchildsemi.com
DM74ALS874B Dual 4-Bit D-Type Edge-Triggered Flip-Flop with 3-STATE Outputs
Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
24-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" Wide
Package Number N24C
Fairchild does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and
Fairchild reserves the right at any time without notice to change said circuitry and specifications.
LIFE SUPPORT POLICY
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD
SEMICONDUCTOR CORPORATION. As used herein:
2. A critical component in any component of a life support
device or system whose failure to perform can be reasonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the
body, or (b) support or sustain life, and (c) whose failure
to perform when properly used in accordance with
instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the
user.
www.fairchildsemi.com
www.fairchildsemi.com
6
Similar pages