Multiplexer (MUX)-

Multiplexer is a logic circuit which has number of inputs and only one output. It rates one of the several inputs so it is also called as data selector.

BCD to 7 segment decoder using IC 7448-

7448 IC is used to drive common cathode type display so it use active high output these decoder also convert BCD input into corresponding decimal output.
Ex. When BCD input 0011 is applied then 7 segments LED will display decimal number 3 in which e & f LED’s segment will be OFF and remaining will be ON.

Working of BCD to 7 segment decoder using IC 7447-

It uses common anode configuration si it gives active low output. These are outputs for IC 7447 these output are given to be corresponding 7 segment display through resistor. These resistors are used to limit the flow of current the truth table.
Ex- When BCD input 0011 is applied to 7447 IC then 7 segment displays will display decimal number 3. But it is active low output. So that only e & f segment will be ON and remaining will be OFF.

Blanking Input-

If it is connected to logic ‘0’ then display will switch off for any BCD input. So for normal operation it isalways connected to logic ‘1’ or high.

Ripple Blanking output-
These is output which is normally at logic ‘1’ and it goes logic ‘0’ during blanking interval.

Ripple Blanking output-

These is output which is normally at logic ‘1’ and it goes logic ‘0’ during blanking interval.

Blanking Input-

If it is connected to logic ‘0’ then display will switch off for any BCD input. So for normal operation it is always connected to logic ‘1’ or high.

Ripple blanking Input-

It is also connected to logic 1 for normal decoding operation. If it is connected to 0 the display output will be display data for normal 7 segment decoding. All BCD input expect ‘0’ and when BCD input is ‘0’ then 7 segment become off. So that for ‘0’ output it is always connected to logic ‘1’.

Lamp Test-

This is used to check the segment of LED. For normal operation it is connected to logic 1. If it is connected to logic 0 then all LED’s segments of the display will be on.

Half Adder-

Half adder is a logic circuit which is used to perform addition of two single bits. If consists of Ex-OR gate to give some result. Half adder has two inputs and two outputs.