5-1
FACT DATA
The MC74AC273/74ACT273 has eight edge-triggered D-type flip-flops with
individual D inputs and Q outputs. The common buffered Clock (CP) and Master
Reset (MR
) inputs load and reset (clear) all flip-flops simultaneously.
The register is fully edge-triggered. The state of each D input, one setup time
before the LOW-to-HIGH clock transition, is transferred to the corresponding flipflop’s Q output.
All outputs will be forced LOW independently of Clock or Data inputs by a LOW
voltage level on the MR
input. The device is useful for applications where the true
output only is required and the Clock and Master Reset are common to all storage
elements.
• Ideal Buffer for MOS Microprocessor or Memory
• Eight Edge-Triggered D Flip-Flops
• Buffered Common Clock
• Buffered, Asynchronous Master Reset
• See MC74AC377 for Clock Enable Version
• See MC74AC373 for Transparent Latch Version
• See MC74AC374 for 3-State Version
• Outputs Source/Sink 24 mA
• ′ACT273 Has TTL Compatible Inputs
1920 18 17 16 15 14
21 3 4 5 6 7
V
CC
13
8
12
9
11
10
Q7D7D6Q6Q5D5D4Q4CP
MR
Q0D0D1Q1Q2D2D3Q3GND
PIN NAMES
D0–D7 Data Inputs
MR
Master Reset
CP Clock Pulse Input
Q0–Q7Data Outputs
OCTAL D FLIP-FLOP
N SUFFIX
CASE 738-03
PLASTIC
DW SUFFIX
CASE 751D-04
PLASTIC
LOGIC SYMBOL
Q0Q1Q2Q3Q4Q5Q6Q
7
D0D1D2D3D4D5D6D
7
CP
MR
MC74AC273 MC74ACT273
5-2
FACT DATA
D
0
D
1
D
2
D
3
D
4
D
5
D
6
D
7
O
0
O
1
O
2
O
3
O
4
O
5
O
6
O
7
D Q
CP
R
D
D Q
CP
R
D
D Q
CP
R
D
D Q
CP
R
D
D Q
CP
R
D
D Q
CP
R
D
D Q
CP
R
D
D Q
CP
R
D
CP
MR
Please note that this diagram is provided only for the understanding of logic
operations and should not be used to estimate propagation delays.
LOGIC DIAGRAM
MODE SELECT-FUNCTION TABLE
MR CP D
n
Q
n
Reset (Clear) L X X L
Load ′1′ H H H
Load ′0′ H L L
H = HIGH Voltage Level
L = LOW Voltage Level
X = Immaterial
= LOW-to-HIGH Clock Transition
MAXIMUM RATINGS*
Symbol Parameter Value Unit
V
CC
DC Supply Voltage (Referenced to GND) –0.5 to +7.0 V
V
in
DC Input Voltage (Referenced to GND) –0.5 to VCC +0.5 V
V
out
DC Output Voltage (Referenced to GND) –0.5 to VCC +0.5 V
I
in
DC Input Current, per Pin ±20 mA
I
out
DC Output Sink/Source Current, per Pin ±50 mA
I
CC
DC VCC or GND Current per Output Pin ±50 mA
T
stg
Storage Temperature –65 to +150 °C
* Maximum Ratings are those values beyond which damage to the device may occur. Functional operation should be restricted to the Recommended
Operating Conditions.
MC74AC273 MC74ACT273
5-3
FACT DATA
RECOMMENDED OPERATING CONDITIONS
Symbol Parameter Min Typ Max Unit
Vin, V
out
DC Input Voltage, Output Voltage (Ref. to GND) 0 V
CC
V
Input Rise and Fall Time (Note 1)
′AC Devices except Schmitt Inputs
′AC Devices except Schmitt Inputs
Input Rise and Fall Time (Note 2)
Input Rise and Fall Time (Note 2)
′ACT Devices except Schmitt Inputs
T
J
Junction Temperature (PDIP) 140 °C
T
A
Operating Ambient Temperature Range –40 25 85 °C
I
OH
Output Current — High –24 mA
I
OL
Output Current — Low 24 mA
1. Vin from 30% to 70% VCC; see individual Data Sheets for devices that differ from the typical input rise and fall times.
2. Vin from 0.8 V to 2.0 V; see individual Data Sheets for devices that differ from the typical input rise and fall times.
DC CHARACTERISTICS
TA = +25°C
TA =
–40°C to +85°C
Typ Guaranteed Limits
V
IH
3.0 1.5 2.1 2.1 V
OUT
= 0.1 V
4.5 2.25 3.15 3.15 V or VCC – 0.1 V
5.5 2.75 3.85 3.85
V
IL
3.0 1.5 0.9 0.9 V
OUT
= 0.1 V
4.5 2.25 1.35 1.35 V or VCC – 0.1 V
5.5 2.75 1.65 1.65
V
OH
3.0 2.99 2.9 2.9 I
OUT
= –50 µA
4.5 4.49 4.4 4.4 V
5.5 5.49 5.4 5.4
*VIN = VIL or V
I
OH
–24 mA
5.5 4.86 4.76 –24 mA
V
OL
3.0 0.002 0.1 0.1 I
OUT
= 50 µA
4.5 0.001 0.1 0.1 V
5.5 0.001 0.1 0.1
*VIN = VIL or V
I
OL
24 mA
5.5 0.36 0.44 24 mA
I
IN
Maximum Input
Leakage Current
5.5 75 mA V
OLD
= 1.65 V Max
I
OHD
5.5 –75 mA V
OHD
= 3.85 V Min
I
CC
Maximum Quiescent
Supply Current
* All outputs loaded; thresholds on input associated with output under test.
†Maximum test duration 2.0 ms, one output loaded at a time.
Note: IIN and ICC @ 3.0 V are guaranteed to be less than or equal to the respective limit @ 5.5 V VCC.