HD74HCT240 Datasheet, PDF (4/7 Pages) Hitachi Semiconductor – Octal Buffers/Line Drivers/Line Receivers(with inverted 3-state outputs)

HD74HCT240
Test Circuit
V_CC
Input
Pulse Generator
Zout = 50 Ω
V_CC
1G, 2G
Output
1Y1 to 2Y4
1A1 to 2A4
1 k Ω _S1
C_L =
50 pF
OPEN
GND
V_CC
Note : 1. C_L includes probe and jig capacitance.
TEST
t_PLH / t_PHL
t_ZH / t_HZ
t_ZL / t_LZ
S1
OPEN
GND
V_CC
Waveforms
• Waveform – 1
Input A
Output Y
t_f
90 %
1.3 V
10 %
t_PLH
t_r
10 %
90 %
1.3 V
t_PHL
1.3 V
10 %
90 %
90 %
1.3 V
10 %
t_TLH
t_THL
V_CC
0V
V_OH
V_OL
• Waveform – 2
t_f
90 %
Input G
1.3 V
10 %
t_ZL
t_r
10 %
90 %
1.3 V
t_LZ
Waveform – A
Waveform – B
1.3 V
t_ZH
1.3 V
10 %
t_HZ
90 %
V_CC
0V
V_OH
V_OL
V_OH
V_OL
Notes : 1. Input waveform : PRR ≤ 1 MHz, duty cycle 50%, t_r ≤ 6 ns, t_f ≤ 6 ns
2. Waveform– A is for an output with internal conditions such that the
output is low except when disabled by the output control.
3. Waveform– B is for an output with internal conditions such that the
output is high except when disabled by the output control.
4. The output are measured one at a time with one transition per measurement.
Rev.2.00 Mar 30, 2006 page 4 of 6