DM74ALS390 Datasheet, PDF (1/6 Pages) National Semiconductor (TI) – Dual 4-Bit Decade Counters

PRELIMINARY
April 1987
DM54ALS390 DM74ALS390 Dual 4-Bit Decade Counters
General Description
Each of these monolithic counters contains eight master-
slave flip-flops and additional gating to implement two inde-
pendent four bit counters in a single package
To use their maximum count length the B input is connect-
ed to the QA output The input count pulses are applied to
input A and the outputs are as described in the appropriate
truth table A symmetrical divide-by-ten count can be ob-
tained by connecting the QD output to the A input and ap-
plying the input count to the B input
Features
Y _{Switching specifications at 50 pF}
Y _{Switching specifications guaranteed over full tempera-}
ture and V_CC range
Y _{Advanced oxide-isolated ion-implanted Schottky TTL}
process
Y _{Individual clocks for A and B flip-flops provide dual di-}
vide-by-2 and divide-by-5 counters
Y _{Direct clear for each 4-bit counter}
Connection Diagram
Function Tables
BCD Count Sequence
(See Note 2)
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
L
H
L
H
TL F 9169 – 1
Order Number DM54ALS390J DM74ALS390M or
DM74ALS390N
See NS Package Number J16A M16A or N16A
6
L
H
H
L
7
L
H
H
H
8
H
L
L
L
9
H
L
L
H
Bi-Quinary (5-2)
(See Note 3)
Count
Output
QA QD QC QB
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
H
L
L
L
6
H
L
L
H
7
H
L
H
L
8
H
L
H
H
9
H
H
L
L
Note 2 Output QA is connected to input B for BCD count
Note 3 Output QD is connected to input A for bi-quinary count
H e High Logic Level L e Low Logic Level
This document contains information on a product under development NSC reserves the right to change or discontinue this product without notice
C1995 National Semiconductor Corporation TL F 9169
RRD-B30M105 Printed in U S A