M74HC390 STMICROELECTRONICS [STMicroelectronics], M74HC390 Datasheet - Page 2

• Manufacturer Part Number: M74HC390
• Description: DUAL DECADE COUNTER
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

M54/M74HC390
INPUT AND OUTPUT EQUIVALENT CIRCUIT
TRUTH TABLE
Note: * Output QA is connected to input CLOCK B for BCD count.
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** Output QD is connected to input CLOCK A for bi-quinary count.
CLOCK A
COUNT
X
X
0
1
2
3
4
5
6
7
8
9
QD
H
H
L
L
L
L
L
L
L
L
CLOCK B
INPUTS
X
X
BCD COUNT *
QC
H
H
H
H
L
L
L
L
L
L
QB
H
H
H
H
L
L
L
L
L
L
CLEAR
H
L
L
QA
H
H
H
H
H
L
L
L
L
L
OUTPUTS
QA
QA
H
H
H
H
H
L
L
L
L
L
L
QUINARY COUNT UP
BINARY COUNT UP
BI-QUINARY **
QD
QB
H
H
L
L
L
L
L
L
L
L
L
OUTPUTS
QC
QC
H
H
H
H
L
L
L
L
L
L
L
QB
QD
H
H
H
H
L
L
L
L
L
L
L