DESCRIPTION
The HEF4511B is a BCD to 7-segment
latch/decoder/driver with four address inputs (DA to DD),
an active LOW latch enable input (EL), an active LOW
ripple blanking input (BI), an active LOW lamp test input
(LT), and seven active HIGH n-p-n bipolar transistor
segment outputs (Oa to Og).
When EL is LOW, the state of the segment outputs (Oa to
Og) is determined by the data on DA to DD.
When EL goes HIGH, the last data present on DA to
DD are stored in the latches and the segment outputs
remain stable. When LT is LOW, all the segment outputs
are HIGH independent of all other input conditions. With
LT HIGH, a LOW on BI forces all segment outputs LOW.
The inputs LT and BI do not affect the latch circuit.