## Overview of the CD74ACT05M The **CD74ACT05M** is a high-speed CMOS logic integrated circuit. Specifically, it consists of **six independent inverters with open-drain outputs**. It belongs to the "ACT" (Advanced CMOS with TTL-compatible inputs) family, making it ideal for interfacing between different voltage levels or driving loads that require a pull-up resistor. --- ### 1. Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Logic Type** | Inverter (NOT Gate) | | **Number of Elements** | 6 (Hex) | | **Output Type** | Open-Drain | | **Supply Voltage ($V_{CC}$)** | 4.5V to 5.5V | | **Input Logic Threshold** | TTL-Compatible | | **Propagation Delay ($t_{pd}$)** | ~3.5ns to 8.5ns (at 5V) | | **Package Type** | SOIC-14 (Small Outline IC) | | **Operating Temperature** | -55°C to +125°C | --- ### 2. Functional Characteristics #### Open-Drain Architecture Unlike standard "Push-Pull" outputs, an **Open-Drain** output can only pull the signal to Ground (Logic Low). To achieve a Logic High, an external **pull-up resistor** must be connected to the output pin. **Benefits of Open-Drain:** * **Wired-AND Logic:** Multiple outputs can be tied together to a single pull-up resistor. * **Level Shifting:** The output can be pulled up to a voltage different from $V_{CC}$ (e.g., driving a 12V relay from a 5V logic signal). #### ACT Technology The "ACT" designation means: 1. **A (Advanced):** Faster switching speeds and higher drive capability than the older 74HC series. 2. **CT (CMOS with TTL):** The input thresholds are designed to recognize TTL levels (Low $\le$ 0.8V, High $\ge$ 2.0V), allowing it to be driven by older bipolar logic or low-voltage microcontrollers. --- ### 3. Pin Configuration (SOIC-14) | Pin # | Symbol | Description | | :--- | :--- | :--- | | 1, 3, 5, 9, 11, 13 | 1A - 6A | Data Inputs | | 2, 4, 6, 8, 10, 12 | 1Y - 6Y | Data Outputs (Open-Drain) | | 7 | GND | Ground | | 14 | $V_{CC}$ | Positive Supply | --- ### 4. Typical Applications * **LED Driving:** Directly sinking current to turn on an LED. * **Bus Interfacing:** Creating a shared communication line where multiple devices can pull the line low. * **Voltage Level Translation:** Converting 5V logic signals to higher or lower voltage domains using the pull-up resistor. * **Signal Inversion:** Simple NOT gate logic for control signals. ---