IC 4518 – Dual 4-Bit BCD Counter

Overview

The IC 4518 is a dual 4-bit binary-coded decimal (BCD) counter designed for counting applications in digital circuits. It is capable of counting from 0 to 9 (a decade) in each of its two independent counters. This IC is used in various applications such as digital clocks, counters, and event measurement systems.

Features

• Dual BCD Counters: Contains two independent 4-bit BCD counters, each capable of counting from 0 to 9.
• Asynchronous Reset: Provides an asynchronous reset function for initializing the counter to zero.
• Clock Input: Operates with a clock signal to increment the counter on each clock pulse.
• Binary Output: Outputs the count value in binary-coded decimal format.
• Carry-Out Function: Provides a carry-out signal that can be used to cascade counters or trigger additional counting stages.

Pin Configuration

The IC 4518 is typically available in a 16-pin Dual In-line Package (DIP) format. The pinout is as follows:

• Pin 1: Q1 (Least Significant Bit, Counter 1)
• Pin 2: Q0 (Most Significant Bit, Counter 1)
• Pin 3: Q2 (Least Significant Bit, Counter 2)
• Pin 4: Q3 (Most Significant Bit, Counter 2)
• Pin 5: Reset (Asynchronous Reset for both counters)
• Pin 6: Clock (Clock Input for Counter 1)
• Pin 7: Enable (Counter Enable for Counter 1)
• Pin 8: Ground (GND)
• Pin 9: Vcc (Positive Supply Voltage)
• Pin 10: Q3 (Most Significant Bit, Counter 1)
• Pin 11: Q2 (Least Significant Bit, Counter 1)
• Pin 12: Q1 (Least Significant Bit, Counter 2)
• Pin 13: Q0 (Most Significant Bit, Counter 2)
• Pin 14: Carry-Out (Carry-Out for Counter 1)
• Pin 15: Clock (Clock Input for Counter 2)
• Pin 16: Enable (Counter Enable for Counter 2)

Working Principle

The IC 4518 functions as follows:

1. Counting Operation: The IC counts clock pulses on the Clock input pin, incrementing the counter value from 0 to 9.
2. BCD Output: The output is provided in binary-coded decimal format, where each counter represents a digit in binary.
3. Reset Function: The asynchronous Reset pin allows for resetting both counters to zero regardless of the clock state.
4. Carry-Out: The Carry-Out pin signals when the counter has reached its maximum count and can be used to cascade additional counters or stages.

Applications

• Digital Clocks: Used to count seconds, minutes, and hours in digital clock circuits.
• Frequency Counters: Measures the frequency of incoming signals by counting pulses.
• Event Counters: Counts occurrences of specific events in various applications.
• Measurement Systems: Used in digital measurement systems to count and display numerical values.
• Frequency Division: Can be used to divide frequencies in electronic circuits.

Example Circuit

• Digital Clock: Connect the IC to a crystal oscillator and a display to count time and show the result on a 7-segment display.
• Frequency Counter: Use the IC to measure the frequency of a signal by counting the pulses.
• Event Counter: Implement the IC in a system to count events such as production items or sensor triggers.

Advantages

• Dual Counters: Provides two independent counting sections for versatile applications.
• BCD Output: Outputs the count in a format that is easily readable and usable in displays.
• High-Speed Operation: Capable of high-speed counting for fast applications.
• Precise Counting: Ensures accurate counting with binary-coded decimal output.
• Versatile Use: Suitable for a variety of counting and measurement tasks.

Conclusion

The IC 4518 is a versatile dual 4-bit BCD counter integrated circuit designed for accurate and reliable counting applications. Its ability to count from 0 to 9 in each of its two independent counters, along with features like asynchronous reset and carry-out, makes it ideal for use in digital clocks, frequency counters, and event measurement systems. With its standard pin configuration and robust performance, the IC 4518 is a valuable component for various digital counting and measurement applications.

IC 4541 – Dual Decade Counter