SN74LS247N | Texas Instruments

BCD-To-Seven-Segment Decoder/Driver, SN74LS247N, Texas Instruments

The SN74LS247N is electrically and functionally identical to the SN54LS47/SN74LS47 and has the same pin assignment as its equivalent. It can be used interchangeably in present or future designs to offer designers a choice between two indicator fonts. The SN74LS247N compose the 6 and 9 without tails. Composition of all other characters, including display patterns for BCD inputs above nine, is identical. The SN74LS247N features active-low outputs designed for driving indicators directly. The circuit has full ripple-blanking input/output controls and a lamp test input.

Segment identification and resultant displays are shown below. Display patterns for BCD input counts above 9 are unique symbols to authenticate input conditions. This circuit incorporates automatic leading and/or trailing-edge zero-blanking control (RBI\ and RBO). Lamp test (LT) may be performed at any time when the BI/RBO\ node is at a high level. It contains an overriding blanking input (BI) which can be used to control the lamp intensity by pulsing or to inhibit the output. The input and output are entirely compatible for use with TTL logic outputs.

Features

• Open-Collector Outputs Drive Indicators Directly
• Lamp-Test Provision
• Leading/Trailing Zero Suppression