Precision frequency counter

This circuit illustrates a straightforward 4-digit frequency counter utilizing an ICM7217 and an ICM7207, which generates the 1-second gating window along with the STORE and RESET signals. The display directly indicates frequency in hertz based on the connections. When pin 11 of the ICM7207 is linked to VDD, the gating duration is set to 0.1 seconds, allowing the least significant digit to display values in tens of hertz. For reduced gating intervals, a 6.5536-MHz crystal can be employed, providing a gating time of 0.01 seconds with pin 11 connected to VDD and 0.1 seconds with pin 11 left open.

The described circuit operates as a frequency counter, where the ICM7217 serves as the main display driver, capable of handling a 4-digit output. This setup is particularly effective in measuring frequencies in the range of hertz, leveraging the precision of the ICM7207 for time gating. The ICM7207 generates the necessary timing signals, ensuring that the frequency measurement is stable and accurate.

The use of a 6.5536-MHz crystal oscillator allows for precise timing control, which is critical for accurate frequency measurement. When pin 11 of the ICM7207 is connected to VDD, it sets the gating time to 0.1 seconds, effectively allowing the counter to sample the input frequency over this duration. This results in the least significant digit displaying values in increments of tens of hertz, which is suitable for applications requiring moderate frequency resolution.

For applications necessitating shorter gating times, the circuit can utilize the same crystal oscillator to achieve a gating time of 0.01 seconds. This configuration enhances the counter's ability to measure higher frequency signals, making it versatile for various electronic applications. The ability to switch between gating times by merely altering the connection of pin 11 provides flexibility, allowing the user to optimize the circuit for specific measurement tasks.

Overall, this frequency counter design is a practical solution for electronic measurement needs, combining the reliability of the ICM series components with the adaptability offered by crystal oscillator configurations.This circuit shows a simple 4-digit frequency counter using an ICM7217 and an ICM7207 (which provides the 1-s gating window and the STORE and RESET signals). The display reads hertz directly, as connected. With pin 11 of the ICM7027 connected to VDD, the gating time is 0. 1 s. This displays tens of hertz at the least significant digit. For shorter gating times, use a 6. 5536-MHz crystal (0. 01s with pin 11 connected to VD and 0. 1 s with pin 11 open) 🔗 External reference