The document discusses a BCD to 7-segment decoder which converts binary coded decimal (BCD) input into signals that drive the segments of a 7-segment display. A 7-segment display contains 7 LED segments that can be illuminated in different combinations to display numbers or characters. The decoder uses a truth table and Karnaugh maps to simplify the logic and outputs the appropriate signals to light the correct segments based on the 4-bit BCD input. Commonly used ICs like the 7447 contain this decoding logic and are used to interface between BCD inputs and either common-anode or common-cathode 7-segment displays.

1. BCD to 7 Segment Decoder

2. BCD
 binary coded decimal

3. 7-Segment Display
 It is a digital device that can be used for displaying decimal number,
alphabets, and characters.
 contains 7 LED segments
 There are two types of 7-Segment displays.
 Common Cathode
 Common Anode

4. 7-Segment Display
 There are two types of 7-Segment displays.
 Common Cathode
 Common Anode

5. Display combination of decimal
numbers

6. Truth Table
 Assume common cathode 7-Segment display. Suppose the binary
input ABCD to the decoder and output a, b, c, d, e, f, & g for the display.

7. Karnaugh Maps Simplification
 For output a:

8. Karnaugh Maps Simplification
 For output a:

9. Karnaugh Maps Simplification

10. 7-Segment Display Decoder Circuit

11. BCD to 7-Segment Decoder IC & Pin outs
 The commonly used IC for BCD to 7-segment decoding is 7447
 for driving common-anode LEDs

12. BCD to 7-Segment Decoder IC & Pin outs
 common-cathode LEDs