Cmos-universal-logic-probe
The circuit requires only the CD4009AE hex buffer, two resistors, and two LEDs to create a logic probe. This CMOS logic probe has an input impedance of 10^12 ohms and operates within a voltage range of 3 to 15 volts. Additionally, while the LEDs are visible at all voltages, replacing R2 with a 1 kΩ potentiometer allows the user to adjust brightness at lower voltages.
The logic probe circuit utilizes the CD4009AE hex buffer, which is a CMOS device capable of providing high input impedance and low output impedance, making it suitable for detecting digital signals without significantly loading the circuit under test. The input impedance of 10^12 ohms ensures minimal interference with the signal being probed, thereby preserving the integrity of the voltage levels being measured.
The circuit design includes two resistors: one serves as a current limiting resistor for the LEDs, while the second resistor (R2) can be replaced with a 1 kΩ potentiometer. This modification allows users to adjust the brightness of the LEDs, enhancing visibility, especially when operating at lower voltage levels. The two LEDs are configured to indicate the logic states; typically, one LED lights up for a high logic level (near the supply voltage), while the other indicates a low logic level (near ground).
The operational voltage range of 3 to 15 volts provides versatility for various digital circuits, accommodating both low-voltage TTL and higher-voltage CMOS logic families. The logic probe can be used in various applications, including troubleshooting and verifying the functionality of digital circuits. The simplicity of the design makes it an accessible project for both educational purposes and practical use in electronics.
In summary, this logic probe circuit presents a straightforward yet effective solution for monitoring digital signals across a wide voltage range, with user-adjustable features to enhance performance and usability.Only the CD4009AE hex buffer, two resistors, and two LEDs are required for a logic probe. CMOS logic probe features 10120 input impedance and covers 3 to 15 V range. While LEDs are visible at all voltages, a 1-K!l pot in place of R2 will allow the user to increase brightness at lower voltages. 🔗 External reference
The logic probe circuit utilizes the CD4009AE hex buffer, which is a CMOS device capable of providing high input impedance and low output impedance, making it suitable for detecting digital signals without significantly loading the circuit under test. The input impedance of 10^12 ohms ensures minimal interference with the signal being probed, thereby preserving the integrity of the voltage levels being measured.
The circuit design includes two resistors: one serves as a current limiting resistor for the LEDs, while the second resistor (R2) can be replaced with a 1 kΩ potentiometer. This modification allows users to adjust the brightness of the LEDs, enhancing visibility, especially when operating at lower voltage levels. The two LEDs are configured to indicate the logic states; typically, one LED lights up for a high logic level (near the supply voltage), while the other indicates a low logic level (near ground).
The operational voltage range of 3 to 15 volts provides versatility for various digital circuits, accommodating both low-voltage TTL and higher-voltage CMOS logic families. The logic probe can be used in various applications, including troubleshooting and verifying the functionality of digital circuits. The simplicity of the design makes it an accessible project for both educational purposes and practical use in electronics.
In summary, this logic probe circuit presents a straightforward yet effective solution for monitoring digital signals across a wide voltage range, with user-adjustable features to enhance performance and usability.Only the CD4009AE hex buffer, two resistors, and two LEDs are required for a logic probe. CMOS logic probe features 10120 input impedance and covers 3 to 15 V range. While LEDs are visible at all voltages, a 1-K!l pot in place of R2 will allow the user to increase brightness at lower voltages. 🔗 External reference