BCD-to-Seven-Segment Decoder / Driver (with 15 V Outputs)

HD74LS47 features active-low outputs designed for driving incandescent indicators directly. This device has full ripple-blanking input / output controls and a lamp test. Display patterns for BCD input counts above 9 are unique symbols to authenticate input conditions. This circuit incorporates automatic leading and / or trailing-edge zeroblanking control (RBI and RBO). Lamp test (LT) of these types 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 of pulsing or to inhibit the outputs. Inputs and outputs are entirely compatible for use with TTL or DTL logic outputs.