Prison Break

Prison Break adalah antara series yang paling hangat.Kisah tentang dua beradik yang mempunyai....

BCD to 7-segment Decoder

The SN74LS47 are Low Power Schottky BCD to 7-Segment
Decoder/Drivers consisting of NAND gates, input buffers and seven
AND-OR-INVERT gates. They offer active LOW, high sink current
outputs for driving indicators directly. Seven NAND gates and one
driver are connected in pairs to make BCD data and its complement
available to the seven decoding AND-OR-INVERT gates. The
remaining NAND gate and three input buffers provide lamp test,
blanking input / ripple-blanking output and ripple-blanking input.
The circuits accept 4-bit binary-coded-decimal (BCD) and,
depending on the state of the auxiliary inputs, decodes this data to
drive a 7-segment display indicator. The relative positive-logic output
levels, as well as conditions required at the auxiliary inputs, are shown
in the truth tables.

 

Output configurations of the SN74LS47 are
designed to withstand the relatively high voltages required for
7-segment indicators.
These outputs will withstand 15 V with a maximum reverse current
of 250 mA. Indicator segments requiring up to 24 mA of current may
be driven directly from the SN74LS47 high performance output
transistors. Display patterns for BCD input counts above nine are
unique symbols to authenticate input conditions.
The SN74LS47 incorporates automatic leading and/ or trailing-edge
zero-blanking control (RBI and RBO). Lamp test (LT) may be
performed at any time which the BI/RBO node is a HIGH level. This
device also contains an overriding blanking input (BI) which can be
used to control the lamp intensity by varying the frequency and duty
cycle of the BI input signal or to inhibit the outputs.
• Lamp Intensity Modulation Capability (BI/RBO)
• Open Collector Outputs
• Lamp Test Provision
• Leading/Trailing Zero Suppression
• Input Clamp Diodes Limit High-Speed Termination Effects