HD74HC78 Datasheet, PDF (4/7 Pages) Hitachi Semiconductor – Dual J-K Flip-Flops (with Preset, Common Clear and Common Clock)

HD74HC78
Switching Characteristics (C_L = 50 pF, Input t_r = t_f = 6 ns)
Item
Maximum clock
frequency
Propagation delay
time
Pulse width
Setup time
Hold time
Removal time
Output rise/fall
time
Input capacitance
Symbol VCC (V)
fmax
2.0
4.5
6.0
tPLH, tPHL 2.0
4.5
6.0
2.0
4.5
6.0
2.0
4.5
6.0
tw
2.0
4.5
6.0
tsu
2.0
4.5
6.0
th
2.0
4.5
6.0
trem
2.0
4.5
6.0
tTLH, tTHL 2.0
4.5
6.0
Cin
—
Ta = 25°C
Ta = –40 to +85°C
Min Typ Max Min Max Unit
Test Conditions
—— 6
—
5 MHz
— — 30
—
24
— — 35
—
28
— — 150 —
190 ns Clock to Q or Q
— 20 30
—
38
— — 26
—
33
— — 140 —
175 ns Clear to Q or Q
— 18 28
—
35
— — 24
—
30
— — 140 —
175 ns Preset to Q or Q
— 18 28
—
35
— — 24
—
30
80 — — 100
— ns Preset, Clear, Clock
16 8 —
20
—
14 — —
17
—
100 — — 125
— ns J or K to Clock
20 2 —
25
—
17 — —
21
—
5 ——
5
— ns Clock to J or K
5 –1 —
5
—
5 ——
5
—
100 — — 125
— ns Preset or Clear to Clock
20 0 —
25
—
17 — —
21
—
— — 75
—
95 ns
— 5 15
—
19
— — 13
—
16
— 5 10
—
10 pF
Test Circuit
VCC
VCC
Input
Pulse generator
Zout = 50 Ω
Input
Pulse generator
Zout = 50 Ω
Preset
Q
Clock
J
K
Q
Clear
Output
Output
C_L = 50 pF
C_L = 50 pF
Note: C_L includes the probe and jig capacitance.
Rev.2.00, Oct 06, 2005 page 4 of 6