HD74LS78A Datasheet, PDF (3/7 Pages) Hitachi Semiconductor – Dual J-K Flip-Flops(with Preset, Common Clear, and Common Clock)

HD74LS78A
Electrical Characteristics
(Ta = –20 to +75 °C)
Item
Symbol min. typ.* max. Unit
Condition
Input voltage
Output voltage
J, K
VIH
2.0
—
—
V
VIL
—
—
0.8
V
VOH
2.7
—
—
V
VCC = 4.75 V, VIH = 2.7 V, VIL = 0.8 V,
IOH = –400 µA
VOL
—
—
—
—
0.5
0.4
V
IOL = 8 mA
IOL = 4 mA
VCC = 4.75 V, VIH = 2 V,
VIL = 0.8 V
—
—
20
Clear
Preset
IIH
—
—
120
—
—
60
µA VCC = 5.25 V, VI = 2.7 V
Clock
—
—
160
J, K
—
—
–0.4
Input
Clear
current
Preset
IIL**
—
—
–1.6
—
—
–0.8
mA VCC = 5.25 V, VI = 0.4 V
Clock
—
—
–1.6
J, K
—
—
0.1
Clear
Preset
II
—
—
0.6
—
—
0.3
mA VCC = 5.25 V, VI = 7 V
Clock
—
—
0.8
Short-circuit output
current
IOS
–20
—
–100
mA VCC = 5.25 V
Supply current***
ICC
—
4
6
mA VCC = 5.25 V
Input clamp voltage
VIK
—
—
–1.5
V
VCC = 4.75 V, IIN = –18 mA
Notes: * VCC = 5 V, Ta = 25°C
** IIL should not be measured when preset and clear inputs are low at same time.
*** With all outputs open, ICC is measured with the Q and Q outputs high in turn.
At the time of measurement, the clock input is grounded.
Switching Characteristics
(V_CC = 5 V, Ta = 25°C)
Item
Symbol Inputs Outputs min. typ. max. Unit
Condition
Maximum clock frequency
fmax
30
45
MHz
Propagation delay time
tPLH
Clear
—
15
20
ns _{CL = 15 pF, RL = 2 kΩ}
Preset Q, Q
tPHL
Clock
—
15
20
ns
Timing Definition
t_w
Clock
J, K
1.3 V
t_su
1.3 V
t_h
1.3 V
"H" Data
1.3 V
3V
1.3 V
0V
t_su
t_h
3V
"L" Data
1.3 V
0V
Rev.3.00, Jul.22.2005, page 3 of 6