### Overview of the 54ACTQ241 The **54ACTQ241** is a high-performance, radiation-hardened (or military-grade) octal buffer and line driver designed for high-speed, low-power system applications. It belongs to the **FACT (Fairchild Advanced CMOS Technology)** family and is specifically engineered to drive high-capacitance loads while minimizing noise. --- ### Key Technical Specifications | Parameter | Specification | |:---|:---| | **Logic Type** | Octal Buffer / Line Driver (3-State) | | **Logic Family** | 54ACTQ (Advanced CMOS with TTL inputs) | | **Supply Voltage (Vcc)** | 4.5V to 5.5V | | **Input Threshold** | TTL Compatible | | **Output Current** | ±24 mA | | **Propagation Delay** | ~5.0 ns (Typical) | | **Operating Temperature** | -55°C to +125°C (Military Grade) | --- ### Internal Architecture and Functionality The device features eight non-inverting buffers grouped into two sets of four. Each group is controlled by a specific **Output Enable (OE)** pin: 1. **Group 1 (Inputs A1-A4):** Controlled by an active-low enable pin ($\overline{OE}_A$). When LOW, data passes through. 2. **Group 2 (Inputs A5-A8):** Controlled by an active-high enable pin ($OE_B$). When HIGH, data passes through. #### Truth Table | Control Input ($\overline{OE}_A$ / $OE_B$) | Data Input (A) | Output (Y) | |:---:|:---:|:---:| | L / H | L | L | | L / H | H | H | | H / L | X | High-Z (High Impedance) | --- ### Notable Features * **Quiet Series™ Noise Shaping:** The "Q" in ACTQ denotes "Quiet." This technology incorporates internal circuitry to reduce "ground bounce" (noise generated when multiple outputs switch simultaneously). * **High Impedance in Power-Off:** The outputs are designed to be in a high-impedance state when the device is powered down, preventing current backflow. * **3-State Outputs:** Ideal for bus-oriented architectures where multiple devices share the same signal line. * **ACT Technology:** Combines the high speed of FAST™ (Fairchild Advanced Schottky TTL) with the low power consumption of CMOS. --- ### Common Applications 1. **Bus Drivers:** Interfacing microprocessors with memory or peripheral devices over long PCB traces. 2. **Signal Buffering:** Strengthening weak signals to drive multiple gates or high-capacitance loads. 3. **Military and Aerospace:** Due to the 54-series prefix, these parts are often used in harsh environments requiring extended temperature ranges and high reliability. --- ### Typical Pin Configuration (20-Pin Package) ```text +---U---+ OE1 |1 20| VCC A1 |2 19| OE2 Y1 |3 18| A5 A2 |4 17| Y5 Y2 |5 16| A6 A3 |6 15| Y6 Y3 |7 14| A7 A4 |8 13| Y7 Y4 |9 12| A8 GND |10 11| Y8 +-------+ ```