The **4064** is a specific integrated circuit (IC) belonging to the **CMOS 4000 series** family. Its full technical designation is usually the **CD4064**, which is a **4-Bit Bus Buffer with 3-State Outputs**. --- ### 1. Function and Purpose The 4064 acts as an interface between different parts of a digital system. Its primary role is to allow or prevent the flow of data from an input to an output based on a control signal (Enable). | Feature | Description | | :--- | :--- | | **Logic Family** | CMOS (Complementary Metal-Oxide-Semiconductor) | | **Main Function** | Quad Bus Buffer / Driver | | **Output Type** | 3-State (High, Low, and High-Impedance/Disconnect) | | **Input Type** | High Impedance | --- ### 2. Key Specifications These parameters are standard for the CD4000 series logic chips: * **Supply Voltage ($V_{DD}$):** Typically 3V to 18V. * **Operating Temperature:** -55°C to +125°C. * **Propagation Delay:** Approximately 50ns to 100ns (varies by voltage). * **Power Consumption:** Very low static power (characteristic of CMOS). --- ### 3. Logic Symbol and Operation The "3-State" capability is the most important feature of the 4064. Unlike standard gates that are always either "ON" (1) or "OFF" (0), the 4064 has a third state: **High-Impedance (Hi-Z)**. #### Truth Table (Single Buffer) | Input (A) | Enable (E) | Output (Y) | State | | :--- | :--- | :--- | :--- | | L | H | L | Data Passed | | H | H | H | Data Passed | | X | L | **Z** | **High-Impedance (Disconnected)** | *(L = Low, H = High, X = Don't Care, Z = Floating/Disconnected)* --- ### 4. Common Applications The 4064 is widely used in legacy digital systems and hobbyist electronics for: 1. **Microprocessor Bus Interfacing:** Connecting multiple devices to a single data bus without causing signal conflicts. 2. **Signal Isolation:** Temporarily disconnecting a part of a circuit to prevent interference. 3. **Driving Capacitive Loads:** Providing extra current to drive longer wires or multiple inputs (fan-out). 4. **Multiplexing:** Selecting which input source gets to send data to a central processor. --- ### 5. Equivalent/Alternative Parts If you cannot find the CD4064, you may look for these alternatives depending on the logic family required: * **74HC125:** A high-speed CMOS quad buffer (7400 series equivalent). * **CD4503:** Hex 3-state non-inverting buffer (CMOS). * **CD4050:** Non-inverting hex buffer (Note: This lacks the 3-state High-Z output).