## Overview of the 74ABT373CFCX The **74ABT373CFCX** is a high-performance integrated circuit belonging to the **ABT (Advanced BiCMOS Technology)** family. It is an octal transparent D-type latch with 3-state outputs. This component is widely used in bus-oriented systems where high speed, high drive capability, and low power consumption are required. --- ### 1. Key Technical Specifications | Parameter | Value / Description | | :--- | :--- | | **Logic Family** | ABT (Advanced BiCMOS) | | **Function** | Octal Transparent D-Latch | | **Output Type** | 3-State (High-Z capability) | | **Supply Voltage (Vcc)** | 4.5V to 5.5V | | **Propagation Delay** | ~3.3 ns (Typical) | | **Output Current ($I_{OH}/I_{OL}$)** | -32 mA / 64 mA | | **Package Type** | SSOP (Shrink Small Outline Package) | | **Packing** | Tape & Reel (indicated by the 'X' suffix) | --- ### 2. Functional Description The 74ABT373 consists of eight D-type latches with 3-state outputs. It operates based on two primary control signals: 1. **Latch Enable (LE):** * When **LE is High**, the Q outputs follow the Data (D) inputs (Transparent mode). * When **LE goes Low**, the data present at the inputs is latched and held at the outputs. 2. **Output Enable ($\overline{OE}$):** * When **$\overline{OE}$ is Low**, the latched data is sent to the output pins. * When **$\overline{OE}$ is High**, the outputs enter a high-impedance state (High-Z), effectively disconnecting the device from the bus. --- ### 3. Logic Table | Operating Mode | $\overline{OE}$ | LE | D | Output (Q) | | :--- | :--- | :--- | :--- | :--- | | **Transparent** | L | H | L | L | | **Transparent** | L | H | H | H | | **Latched** | L | L | X | $Q_0$ (No change) | | **High Impedance** | H | X | X | Z | *Legend: L = Low, H = High, X = Don't Care, Z = High Impedance.* --- ### 4. Hardware Pinout Considerations The "CFCX" suffix specifically denotes the package style (SSOP). The pins are typically organized as follows: * **$D_0 - D_7$:** 8-bit Data Inputs. * **$Q_0 - Q_7$:** 8-bit Data Outputs. * **LE:** Latch Enable pin. * **$\overline{OE}$:** Output Enable pin (Active Low). * **Vcc / GND:** Power supply pins. --- ### 5. Key Advantages of ABT Technology * **BiCMOS Architecture:** Combines the low power consumption of CMOS with the high-speed, high-drive capabilities of Bipolar transistors. * **Live Insertion Support:** ABT circuitry is designed to allow the device to be powered up or down without generating bus glitches. * **High Drive:** The 64mA sink current ($I_{OL}$) makes it ideal for driving heavily loaded backplanes or long bus lines. ---