HD74LS669 Datasheet, PDF (4/9 Pages) Hitachi Semiconductor – Synchronous Up/Down 4-bit Binary Counters

HD74LS669
Switching Characteristics
(V_CC = 5 V, Ta = 25°C)
Item
Symbol Inputs Outputs min.
typ.
max.
Unit Condition
Maximum clock frequency
ƒ_max
25
32
—
MHz
t_PLH
Clock
Ripple
—
26
40
ns
t_PHL
Carry
—
40
60
Propagation delay time
t_PLH
t_PHL
—
Clock Q_A to Q_D
—
18
18
27
27
ns C_L = 15 pF,
R_L = 2 kΩ
t_PLH
Enable T ^Ripple
—
11
17
ns
t_PHL
Carry
—
29
45
t_PLH
Up/Down ^Ripple
—
22
35
ns
t_PHL
Carry
—
26
40
Count Sequence
Load
A
Data ^B
Inputs _C
D
Clock
U/D
P and T
Q_A
Q_B
Q_C
Q_D
Ripple
Carry
Output
13 14 15 0 1 2
2 2 1 0 15 14 13
Load
Count Up
Inhibit
Count Down
Rev.2.00, Feb.18.2005, page 4 of 8