## Technical Overview: CD74ACT05EE4 The **CD74ACT05EE4** 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 Family** | ACT (Advanced CMOS TTL-Compatible) | | **Logic Type** | Inverter (Hex) | | **Output Type** | Open-Drain | | **Supply Voltage ($V_{CC}$)** | 4.5V to 5.5V | | **Input Logic High ($V_{IH}$)** | 2.0V (Min) | | **Input Logic Low ($V_{IL}$)** | 0.8V (Max) | | **Propagation Delay** | ~5ns to 8.5ns (Typical) | | **Package Type** | PDIP-14 (Plastic Dual In-Line Package) | | **Operating Temperature** | -55°C to +125°C | --- ### 2. Functional Characteristics #### Open-Drain Output Unlike standard push-pull outputs, an **open-drain** output can only pull the signal to Ground (Low). To achieve a Logic High state, an external **pull-up resistor** must be connected to a voltage source. * **Advantage:** This allows for "Wired-AND" logic configurations. * **Voltage Shifting:** You can pull the output to a higher or lower voltage than the chip's $V_{CC}$ (up to 5.5V). #### TTL Compatibility The "ACT" designation means the input thresholds are designed to be compatible with standard TTL (Transistor-Transistor Logic) levels, even though the internal structure is CMOS. This allows the chip to be driven by older 5V TTL systems while maintaining low CMOS power consumption. --- ### 3. Pinout Configuration (14-Pin PDIP) | Pin Number | Symbol | Function | | :--- | :--- | :--- | | 1, 3, 5, 9, 11, 13 | 1A to 6A | Data Inputs | | 2, 4, 6, 8, 10, 12 | 1Y to 6Y | Open-Drain Outputs | | 7 | GND | Ground | | 14 | $V_{CC}$ | Supply Voltage (5V) | --- ### 4. Common Applications * **Level Shifting:** Converting signals between different logic families. * **Driving LEDs/Relays:** Since it can sink current effectively, it is often used to drive small loads. * **Wired-OR/AND Logic:** Multiple open-drain outputs can be tied together to a single pull-up resistor. * **Bus Interfacing:** Managing data lines where multiple devices might need to control a single wire. --- ### 5. Implementation Example (Verilog) If you were simulating the behavior of one gate of this IC in a hardware description language: ```verilog // Behavioral model of one open-drain inverter module act05_inverter ( input wire A, output wire Y ); // Y is driven to 0 if A is high; // Y is high-impedance (tri-state) if A is low. assign Y = (A) ? 1'b0 : 1'bz; endmodule ```