Datasheet
SDLS213B − DECEMBER 1983 − REVISED NOVEMBER 2004
11
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
PARAMETER MEASUREMENT INFORMATION
B
†
CLR
Q
3 V
3 V
0 V
0 V
V
OH
V
OL
≥ 50 ns
CONDITION 4: TRIGGERING FROM POSITIVE TRANSITION OF CLR
≥ 50 ns
A
‡
CLR
Q
Q
3 V
3 V
0 V
0 V
V
OH
V
OH
V
OL
V
OL
t
w
≥ 60 ns
t
PLH
t
PHL
t
PHL
t
PLH
CONDITION 5: TRIGGER FROM A, THEN CLR
A
‡
Q
Q
3 V
0 V
V
OH
V
OH
V
OL
V
OL
t
w
CONDITION 6: TRIGGER FROM A
t
w
†
A is low.
‡
B and CLR
are high.
NOTES: A. Input pulses are supplied by generators having the following characteristics: PRR ≤ 1 MHz, Z
O
≈ 50Ω; for SN54/74221, t
r
≤ 7 ns,
t
f
≤ 7 ns, for SN54/74LS221, t
r
≤ 15 ns, t
f
≤ 6 ns.
B. All measurements are made between the 1.5-V points of the indicated transitions for the SN54/74221 or between the 1.3-V points
for the SN54/74LS221.
Figure 1. Switching Characteristics (Continued)