MC74HC74A
http://onsemi.com
2
RESET 1
DATA 1
CLOCK 1
SET 1
RESET 2
DATA 2
CLOCK 2
SET 2
1
2
3
4
13
12
11
10
5
6
9
8
Q1
Q2
PIN 14 = VCC
PIN 7 = GND
FUNCTION TABLE
Inputs
Outputs
Set Reset Clock Data
Q
LH
X
HL
X
LH
L
X
H*
HH
H
L
HH
L
H
L
X
No Change
H
X
No Change
H
X
No Change
*Both outputs will remain high as long as Set and Reset are low, but the output
states are unpredictable if Set and Reset go high simultaneously.
LOGIC DIAGRAM
PIN ASSIGNMENT
SET 1
CLOCK 1
DATA 1
RESET 1
11
12
13
14
8
9
10
5
4
3
2
1
7
6
SET 2
CLOCK 2
DATA 2
RESET 2
VCC
Q2
GND
Q1
MAXIMUM RATINGS
Symbol
Parameter
Value
Unit
VCC
DC Supply Voltage (Referenced to GND)
– 0.5 to + 7.0
V
Vin
DC Input Voltage (Referenced to GND)
– 0.5 to VCC + 0.5
V
Vout
DC Output Voltage (Referenced to GND)
– 0.5 to VCC + 0.5
V
Iin
DC Input Current, per Pin
± 20
mA
Iout
DC Output Current, per Pin
± 25
mA
ICC
DC Supply Current, VCC and GND Pins
± 50
mA
PD
Power Dissipation in Still Air,
Plastic DIP
SOIC Package
TSSOP Package
750
500
450
mW
Tstg
Storage Temperature
– 65 to + 150
_C
TL
Lead Temperature, 1 mm from Case for 10 Seconds
(Plastic DIP, SOIC or TSSOP Package)
260
300
_C
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress
ratings only. Functional operation above the Recommended Operating Conditions is not implied.
Extended exposure to stresses above the Recommended Operating Conditions may affect device
reliability.
Derating — Plastic DIP: – 10 mW/_C from 65_ to 125_C
SOIC Package: – 7 mW/_C from 65_ to 125_C
TSSOP Package: 6.1 mW/_C from 65_ to 125_C
RECOMMENDED OPERATING CONDITIONS
Symbol
Parameter
Min
Max
Unit
VCC
DC Supply Voltage (Referenced to GND)
2.0
6.0
V
Vin, Vout
DC Input Voltage, Output Voltage (Referenced to GND)
0
VCC
V
TA
Operating Temperature, All Package Types
– 55
+ 125
_C
tr, tf
Input Rise and Fall Time
VCC = 2.0 V
(Figures 1, 2, 3)
VCC = 3.0 V
VCC = 4.5 V
VCC = 6.0 V
0
1000
600
500
400
ns
This device contains protection
circuitry to guard against damage
due to high static voltages or electric
fields. However, precautions must
be taken to avoid applications of any
voltage higher than maximum rated
voltages to this highimpedance cir-
cuit. For proper operation, Vin and
Vout should be constrained to the
range GND v (Vin or Vout) v VCC.
Unused inputs must always be
tied to an appropriate logic voltage
level (e.g., either GND or VCC).
Unused outputs must be left open.