PRODUCT DESCRIPTION / SPECIFICATIONS
The 7-segment display, also written as “seven segment display”, consists of seven LEDs (hence its name) arranged in a rectangular fashion. Each of the seven LEDs is called a segment. The displays common pin is generally used to identify which type of 7-segment display it is. As each LED has two connecting pins, one called the “Anode” and the other called the “Cathode”, there are therefore two types of LED 7-segment display called: Common Cathode (CC) and Common Anode (CA).
Common Anode 7-segment Display:
Common Anode displays are more popular as many logic circuits can sink more current than they can source. Also note that a common cathode display is not a direct replacement in a circuit for a common anode display and vice versa, as it is the same as connecting the LEDs in reverse, and hence light emission will not take place.
Depending upon the decimal digit to be displayed, the particular set of LEDs is forward biased. To display the numerical digit 0, we will need to light up six of the LED segments corresponding to a, b, c, d, e, and f. Thus the various digits from 0 through 9 can be displayed using a 7-segment display as shown.
7-Segment Display Segments for all Numbers:
Then for a 7-segment display, we can produce a truth table giving the individual segments that need to be illuminated in order to produce the required decimal digit from 0 through 9 as shown below.