The basic idea involves driving a common cathode 7-segment LED display using combinational logic circuit. Here we design a simple display decoder circuit using logic gates.Įven though commercial BCD to 7 segment decoders are available, designing a display decoder using logic gates may prove to be beneficial from economical as well as knowledge point of view.īack to top Principle of Display Decoder Circuit It generally has 4 input lines and 7 output lines. Mostly these displays are driven by the output stages of digital ICs (to which the visual indication of the output stages has to be performed) such as latches and decade counters, etc.īut these outputs are in the form of 4-bit binary coded decimal (BCD), and not suitable for directly driving the seven-segment displays.Ī display decoder is used to convert a BCD or a binary code into a 7 segment code. However to display the characters and numbers (in order to produce the decimal readout), seven-segment displays are most commonly used. Generally, LCD and LED segments provide the display output of numerical numbers and characters. Most often seven-segment displays are used to display the digits in digital watches, calculators, clocks, measuring instruments and digital counters, etc. Applications of Display Decoder Circuit.7 Segment Display Decoder Circuit Design.