HD74HC85 Datasheet, PDF (5/8 Pages) Hitachi Semiconductor – 4-Bit Magnitude Comparator

HD74HC85
Test Circuit
VCC
Input
Pulse generator
Zout = 50 Ω
VCC
A3
B3
A2
B2
A1
B1
A0
B0
A<B
A=B
A>B
A>B
A=B
A<B
Output
Output
C_L = 50 pF
Output
C_L = 50 pF
C_L = 50 pF
Note: C_L includes the probe and jig capacitance.
Waveforms
t_r
t_f
90 %
90 %
V_CC
Input
50 %
50 %
10 %
10 %
0V
t_PLH
t_PHL
Same-phase output
50 %
10 %
90 %
t_PHL ^tTLH
90 %
V_OH
50 %
10 %
V_OL
t_PLH
t_THL
Inverse-phase output
90 %
50 %
10 %
90 %
V_OH
50 %
10 %
V_OL
t_THL
t_TLH
Notes: 1. Input waveform: PRR ≤ 1 MHz, Zo = 50 Ω, t_r ≤ 6 ns, t_f ≤ 6 ns
2. The output are measured one at a time with one transition per measurement.
Rev.2.00, Oct 06, 2005 page 5 of 7