TL/F/6518
DM7446A,
DM5447A/DM7447A
BCD
to
7-Segment
Decoders/Drivers
June 1989
DM7446A, DM5447A/DM7447A
BCD to 7-Segment Decoders/Drivers
General Description
The 46A and 47A feature active-low outputs designed for
driving common-anode LEDs or incandescent indicators di-
rectly. All of the circuits have full ripple-blanking input/out-
put controls and a lamp test input. Segment identification
and resultant displays are shown on a following page. Dis-
play patterns for BCD input counts above nine are unique
symbols to authenticate input conditions.
All of the circuits incorporate automatic leading and/or trail-
ing-edge, zero-blanking control (RBI and RBO). Lamp test
(LT) of these devices may be performed at any time when
the BI/RBO node is at a high logic level. All types contain
an overriding blanking input (BI) which can be used to con-
trol the lamp intensity (by pulsing) or to inhibit the outputs.
Features
Y
All circuit types feature lamp intensity modulation
capability
Y
Open-collector outputs drive indicators directly
Y
Lamp-test provision
Y
Leading/trailing zero suppression
Connection Diagram
Dual-In-Line Package
TL/F/6518–1
Order Number DM5447AJ, DM7446AN or DM7447AN
See NS Package Number J16A or N16E
C
1995 National Semiconductor Corporation RRD-B30M105/Printed in U. S. A.