MM74C90 View Datasheet(PDF) - Fairchild Semiconductor
Part Name
Description
MFG CO.
MM74C90 Datasheet PDF : 7 Pages
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Logic Diagrams
MM74C90
MM74C93
Truth Tables
MM74C90 4-Bit Decade Counter BCD Count Sequence
Count
Output
QD QC QB QA
0
L
L
L
L
1
L
L
L
H
2
L
L
H
L
3
L
L
H
H
4
L
H
L
L
5
LHLH
6
LHHL
7
L HHH
8
H
L
L
L
9
H
L
L
H
Output QA is connected to Input B for BCD count.
H = HIGH Level
L = LOW Level
X = Irrelevant
MM74C93 4-Bit Binary Counter Binary Count Sequence
Count
Output
QD QC QB QA
0
L
L
L
L
1
L
L
L
H
2
L
L
H
L
3
L
L
H
H
4
L
H
L
L
5
LHLH
6
L HH L
7
L HHH
8
H
L
L
L
9
H
L
L
H
10
HLHL
11
H LHH
12
H
H
L
L
13
HHLH
14
HHH L
15
HHHH
Output QA is connected to input B for binary count sequence.
H = HIGH Level
L = LOW Level
X = Irrelevant
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