The DM7446A and DM7447A feature active-LOW outputs
designed for driving common-anode LEDs or incandescent
indicators directly. All of the circuits have full ripple-blanking
input/output controls and a lamp test input. Segment
identification and resultant displays are shown on a following
page. Display patterns for BCD input counts above nine
are unique symbols to authenticate input conditions.
All of the circuits incorporate automatic leading and/or trailing-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 control
the lamp intensity (by pulsing) or to inhibit the outputs.