Cmos programmable divide-by-n counter

A single connection change allows division by any integer between 2 and 10. The RCA CD4017A Johnson decade counter is configured as a divide-by-7 counter. A resistor is utilized to maintain the reset line in a low state. When the specified count is reached, the corresponding output and the reset line are activated, resetting the counter. To achieve division by different integers, pin 15 should be connected to the desired output. For instance, pin 1 can be used for a divide-by-2 configuration, or pin 7 for a divide-by-3 configuration. The output of the divider is available on the 0 line.

The RCA CD4017A is a versatile decade counter that can be employed in various digital applications requiring frequency division. This counter operates by sequentially activating its outputs based on the input clock signal. When configured as a divide-by-N counter, it provides a straightforward method to achieve specific division ratios through strategic connections.

In this circuit, pin 15 serves as a reconfiguration point for the counter's division factor. By connecting pin 15 to the appropriate output pin corresponding to the desired division, the counter can be adjusted to divide the input clock frequency by integers ranging from 2 to 10. The configuration for a divide-by-7 counter, for example, involves connecting pin 15 to output pin 7. This allows the counter to output a signal that is one-seventh the frequency of the input clock signal.

The resistor connected to the reset line is critical for maintaining stable operation. It ensures that the reset line remains low, preventing any unintended resets during normal operation. When the counter reaches the predetermined count (in this case, 7), the output at pin 7 goes high, simultaneously driving the reset line high. This action resets the counter, preparing it to start counting anew from zero.

The output of the divider is available on the 0 line, providing a clean and easily accessible signal that reflects the divided frequency. This output can be utilized in various applications, such as timing circuits, frequency synthesis, or in conjunction with other digital components to create more complex logic functions. The simplicity of the RCA CD4017A's design, combined with its flexibility in division ratios, makes it an excellent choice for engineers looking to implement frequency division in their electronic designs.A single connection change permits division by any integer between 2 and 10. The RCA CD4017A Johnson decade counter is shown connected as a divide by 7 counter. The resistor is used to hold the reset line low. When the appropriate number is reached, that output and the reset line are driven high, resetting the counter. To divide by other integers, pin 15 should be connected to the desired output For example, pin 1 for a divide byJ>, or pin 7 for a divide by 3. The output of the divider appears on the 0 line. 🔗 External reference