HD74LS645 Datasheet, PDF (5/7 Pages) Hitachi Semiconductor – Octal Bus Transceivers(non-inverted 3-state outputs)

HD74LS645
Waveforms 2
Notes:
G
t_THL
90 %
t_TLH
3V
3V
90 %
1.3 V
1.3 V
10 %
10 %
0V
0V
Waveform-a
t_ZL
S₁ close
S₂ open
~~ 4.5 V
1.3 V
V_OL
t_LZ
S_1, S₂ close _{~~ 1.5 V}
0.5 V ^VOL
Waveform-b
t_ZH
S₁ open
S₂ close
V_OH
1.3 V
~~ 0 V
t_HZ
V_OH
0.5 V
S_1, S₂ close ^{~~ 1.5 V}
1. Input pulse: t_TLH ≤ 15 ns, t_THL ≤ 6 ns, PRR = 1 MHz, duty cycle 50%
2. Waveform a is an output by internal conditions like "L" except for the case where an output is
disabled by output control.
3. Waveform b is an output by internal conditions like "H" except for the case where an output is
disabled by output control.
Rev.2.00, Feb.18.2005, page 5 of 6