Draw three rectangular blocks to represent the three chips to be used in the design. Label the first block "BCD to Seven Segment Decoder," the second block "Limiting Resistors" and the third block "LCD Seven Segment Display."
Label the four inputs into the decoder that represent the digital numbers as BCD3, BCD2, BCD1 and BCD0.
Label the seven outputs of the converter a, b, c, d, e, f, g, h such that they match the required pin connections for the LED display chip. The pin connections are standardized with a, b, c, d, e, f, g and h labels.
Draw the connections between the LED display chip and the resistor pack and the BCD to seven segment decoder Label the pin numbers on the resistor pack that will make a resistor connection between each input pin of the LED display chip and each output pin of the BCD decoder.
Calculate the value of the limiting resistors needed so that product life of your LED is maximized and current consumption is minimized. Divide the voltage of the power supply you are using to power your circuit by the minimum current necessary to light the LED (from the manufacturer's LED data sheet) to obtain the value of the limiting resistors.
Design a switch network with four single pole double throw switches. Configure the switches so each switch can be used to set the voltage level of a specific BCD numeric input pin (BCD3, BCD2, BCD1 and BCD0) to either a high or low voltage state. This will require one input of the switch be hard wired to the digital power supply's positive terminal and the other side be wired to the digital power supply's ground terminal. Draw the symbols for the power switches and the connections between them and the BCD numeric data inputs of the BCD to seven segment converter.
Enter the schematic of your design in an electronic simulator to simulate the design you drew on paper. Select the LED display, the BCD to seven segment converter, the limiting resistor pack and the single pole double throw switches from those available in the simulator's library. Make the placement and wiring connections with the schematic capture tools of the simulator.
Perform a functional simulation of the design to verify the right LED panel segments will light when the switches are configured to display a numeric number between 0 and 9. Perform a power simulation on the circuit to estimate the power consumption requirements of the circuit. Change the values of the limiting resistor and chip library component values used and rerun the power simulation. Tabulate the power consumption for each design variation to identify the one with lowest power consumption.