HD74LS293 Datasheet, PDF (6/8 Pages) Hitachi Semiconductor – 4-bit Binary Counters

HD74LS293
Waveforms 1
ƒ_max, t_PLH, t_PHL, (Clock→Q)
t_TLH
t_THL
Clock
QA
10%
90% 90%
1.3 V
10%
t_PHL(Measure at tn+2)
1.3 V
t_PLH (Measure at tn+1)
1.3 V
1.3 V
t_PHL (Measure at tn+4) t_PLH (Measure at tn+2)
QB
1.3 V
1.3 V
t_PHL (Measure at tn+8) tPLH (Measure at tn+4)
QC
1.3 V
1.3 V
t_PHL (Measure at tn+16) tPLH (Measure at tn+8)
QD
1.3 V
1.3 V
3V
0V
V_OH
V_OL
V_OH
V_OL
V_OH
V_OL
V_OH
V_OL
Notes:
1. Clock input pulse; t_TLH ≤ 15 ns, t_THL ≤ 6 ns, PRR = 1 MHz, duty cycle = 50%
and : for ƒ_max, t_TLH = t_THL ≤ 2.5 ns.
2. t_n is reference bit time when all outputs are low.
Waveforms 2
t_PHL, (R₀→Q)
t_TLH
t_THL
90% 90%
3V
1.3 V 1.3 V
R0
10%
10%
0V
t_w ≥ 15ns
t_PHL
V_OH
QA to QD
1.3 V
V_OL
Note: t_TLH ≤ 15 ns, t_THL ≤ 5 ns
Rev.3.00, Jul.15.2005, page 6 of 7