74HC390 Datasheet, PDF (4/7 Pages) NXP Semiconductors – Dual decade ripple counter

Philips Semiconductors
Dual decade ripple counter
Product specification
74HC/HCT390
Fig.4 Functional diagram.
BCD COUNT SEQUENCE
FOR 1/2 THE “390”
COUNT
OUTPUTS
Q₀ Q₁ Q₂ Q₃
0
LLLL
1
HL L L
2
L HL L
3
HHL L
4
L L HL
5
HL HL
6
L HHL
7
HHHL
8
LLLH
9
HL L H
Notes
1. Output Q₀ connected to nCP₁
with counter input on nCP₀.
H = HIGH voltage level
L = LOW voltage level
BI-QUINARY COUNT SEQUENCE
FOR 1/2 THE “390”
COUNT
OUTPUTS
Q₀ Q₁ Q₂ Q₃
0
LLLL
1
L HL L
2
L L HL
3
L HHL
4
LLLH
5
HL L L
6
HHL L
7
HL HL
8
HHHL
9
HL L H
Note
1. Output Q₃ connected to nCP₀
with counter input on nCP₁.
December 1990
Fig.5 Logic diagram (one counter).
4