### 54ABT373CPCQB: Technical Overview The **54ABT373CPCQB** is a high-performance, military-grade integrated circuit. It belongs to the **ABT (Advanced BiCMOS Technology)** family and functions as an **Octal Transparent D-Type Latch** with 3-state outputs. --- ### 1. Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Logic Family** | ABT (Advanced BiCMOS) | | **Function** | Octal D-Type Latch (3-State) | | **Supply Voltage ($V_{CC}$)** | 4.5V to 5.5V | | **Package Type** | CQFP (Ceramic Quad Flatpack) | | **Temperature Range** | Military (-55°C to +125°C) | | **Output Drive ($I_{OH}/I_{OL}$)** | -24mA / 48mA | | **Propagation Delay** | ~3.5ns to 5ns (Typical) | --- ### 2. Operational Logic The device contains eight independent D-type latches. It operates based on two primary control pins: 1. **Latch Enable (LE):** * When **LE is High**, the latch is "transparent." The Q outputs follow the data (D) inputs. * When **LE is Low**, the data that meets the setup time requirements is latched and held at the outputs. 2. **Output Enable ($\overline{OE}$):** * When **$\overline{OE}$ is Low**, the eight outputs are active and show the latched data. * When **$\overline{OE}$ is High**, the outputs are placed in a **High-Impedance (High-Z)** state, effectively disconnecting them from the bus. --- ### 3. Part Number Breakdown (Nomenclature) The part number provides specific information about its construction and application: | Segment | Meaning | | :--- | :--- | | **54** | Military Grade (Standard temperature/reliability prefix) | | **ABT** | Advanced BiCMOS Technology (Combines CMOS low power with TTL speed) | | **373** | Function code for Octal D-Type Transparent Latch | | **C** | Ceramic Material | | **PQ** | Package Style: Quad Flatpack (CQFP) | | **B** | Military-level screening/processing (e.g., MIL-STD-883) | --- ### 4. Distinctive Features * **BiCMOS Technology:** Uses CMOS for low power consumption at idle and Bipolar transistors for high-speed switching and heavy drive capability. * **Bus Hold:** Many ABT devices include circuitry to hold the last valid logic state, preventing floating bus lines. * **Radiation/Reliability:** Because it is a "54" series ceramic part, it is designed for aerospace, defense, and harsh environment applications where plastic packages would fail.