M74HC390 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
'M74HC390' PDF : 17 Pages View PDF
M74HC390
3
Truth table
Truth table
Table 2. Truth table
Outputs
COUNT
0
1
2
3
BCD COUNT (1)
QD
QC
QB
QA
L
L
L
L
L
L
L
H
L
L
H
L
L
L
H
H
BI-QUINARY (2)
QA
QD
QC
QB
L
L
L
L
L
L
L
H
L
L
H
L
L
L
H
H
4
L
H
L
L
L
H
L
L
5
L
H
L
H
H
H
L
L
6
L
H
H
L
H
L
L
H
7
L
H
H
H
H
L
H
L
8
H
L
L
L
H
L
H
H
9
H
L
L
H
H
H
L
L
1. Output QA is connected to input CLOCK B for BCD count.
2. Output QD is connected to input CLOCK A for bi-quinary count.
Table 3. Truth table
Inputs
CLOCK A
CLOCK B
X
X
X
CLEAR
H
L
Outputs
QA
QB
QC
QD
L
L
L
L
BINARY COUNT UP
X
L
QUINARY COUNT UP
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