How to cascade two 7-segment decoder ICs together?

[Jotrinelectronic]

In the realm of electronics, the 7-segment decoder IC plays a pivotal role by converting binary or Binary-Coded Decimal (BCD) input into a format suitable for displaying numbers on a 7-segment display. These ICs are indispensable for translating digital data into a visual representation.

Components Required

Before embarking on the cascading process, ensure you have the following components at your disposal:

1. Two 7-segment displays
2. Two 7-segment decoder ICs (commonly 7447, 7448, or similar)
3. BCD input source (e.g., DIP switches or a microcontroller)
4. Resistors (typically 330-470 ohms)
5. Power supply (5V)

Step-by-Step Cascading Guide

Now, let's delve into the specifics of cascading two 7-segment decoder ICs together.

1. Power Supply

Commence by connecting the power supply (5V) to the VCC and GND pins of both 7-segment displays and the two 7-segment decoder ICs. This furnishes the necessary voltage for operation.

2. BCD Input Source

Link your BCD input source (e.g., DIP switches or a microcontroller) to the BCD input pins of the first 7-segment decoder IC. This source will transmit the numerical data to be displayed.

3. First 7-Segment Display

Connect the common cathode or common anode of the first 7-segment display to the respective pins on the first 7-segment decoder IC.
Link each segment (a, b, c, d, e, f, g, and DP) of the first display to the IC's corresponding segment outputs.
Insert a current-limiting resistor (usually 330-470 ohms) in series with each segment to safeguard the LEDs.

4. Cascading Connection

Establish the connection by linking the LT (Lamp Test) and BI/BO (Blanking Input/Output) pins of the first 7-segment decoder IC to the corresponding pins on the second IC. This connection facilitates the cascading operation.

5. Second 7-Segment Display

Connect the common cathode or common anode of the second 7-segment display to the respective pins on the second 7-segment decoder IC.
Attach each segment of the second display to the IC's corresponding segment outputs.
Incorporate current-limiting resistors as required.

6. Testing

Apply power to the circuit and input the desired BCD data. Both 7-segment displays should now accurately exhibit the corresponding numbers.

Conclusion

The skill of cascading two 7-segment decoder ICs proves invaluable when undertaking projects that demand multiple 7-segment displays. This arrangement enables you to display a broader range of numbers, rendering it ideal for applications like digital clocks, scoreboards, and more.

Now that you are well-versed in the process of cascading two 7-segment decoder ICs, you can elevate your electronics projects and effortlessly present numerical information.