CD74HC390 Datasheet, PDF (2/8 Pages) Texas Instruments – High Speed CMOS Logic Dual Decade Ripple Counter

Functional Diagram
CD74HC390, CD74HCT390
1 (15)
nCP0
2 (14)
nMR
÷2
COUNTER
3 (13)
nQ₀
4 (12)
nCP1
GND = 8
V_CC = 16
÷5
COUNTER
5 (11)
6 (10)
nQ₁
nQ₂
7 (9)
nQ₃
TRUTH TABLE
INPUTS
CP
MR
ACTION
↑
L
No Change
↓
L
Count
X
H
All Qs Low
NOTE: H = High Voltage Level, L = Low Voltage Level, X = Don’t Care,
↑ = Transition from Low to High Level, ↓ = Transition from High to Low.
BCD COUNT SEQUENCE FOR 1/2 THE 390
B-QUINARY COUNT SEQUENCE FOR 1/2 THE 390
OUTPUTS
COUNT
Q0
Q1
Q2
Q3
0
L
L
L
L
1
H
L
L
L
2
L
H
L
L
3
H
H
L
L
4
L
L
H
L
5
H
L
H
L
6
L
H
H
L
7
H
H
H
L
8
L
L
L
H
9
H
L
L
H
NOTE: Output nQ0 connected to nCP1 with counter input on nCP0.
OUTPUTS
COUNT
Q0
Q1
Q2
Q3
0
L
L
L
L
1
L
H
L
L
2
L
L
H
L
3
L
H
H
L
4
L
L
L
H
5
H
L
L
L
6
H
H
H
L
7
H
L
H
L
8
H
H
H
L
9
H
L
L
H
NOTE: Output nQ3 connected to nCP0 with counter input on nCP1.
2