## Technical Overview of the 74ABT373CMSACX The **74ABT373CMSACX** is a high-performance integrated circuit (IC) belonging to the **Advanced BiCMOS Technology (ABT)** family. It is an octal transparent D-type latch with 3-state outputs. This device combines the high speed of bipolar logic with the low power consumption of CMOS technology. --- ### 1. Key Features and Specifications | Parameter | Specification | | :--- | :--- | | **Logic Family** | ABT (Advanced BiCMOS) | | **Logic Type** | Octal Transparent D-Latch | | **Output Type** | 3-State (Tri-state) | | **Voltage Supply Range** | 4.5V to 5.5V | | **Current Output (High/Low)** | -32 mA / 64 mA | | **Propagation Delay** | Approx. 3.3ns to 4.5ns | | **Package Type** | SSOP-20 (Shrink Small Outline Package) | | **Operating Temperature** | -40°C to +85°C | --- ### 2. Functional Description The device consists of eight D-type latches. It is designed specifically for driving high-capacitance loads or low-impedance backplanes. #### Pins and Control * **D0–D7 (Data Inputs):** These are the 8-bit parallel data input lines. * **Q0–Q7 (Data Outputs):** These are the 8-bit buffered outputs. * **LE (Latch Enable):** When high, the latches are transparent (outputs follow inputs). When low, data is latched and held. * **OE (Output Enable):** When low, outputs are active. When high, outputs are in a high-impedance state (Z). #### Logic Truth Table | OE | LE | D | Q (Output) | Mode | | :---: | :---: | :---: | :---: | :--- | | L | H | H | H | Transparent (High) | | L | H | L | L | Transparent (Low) | | L | L | X | Q0 | Latched (No change) | | H | X | X | Z | High Impedance | --- ### 3. Advantages of the ABT Series 1. **High Drive Capability:** The 64mA sink current makes it ideal for driving memory buses or backplanes. 2. **Low Static Power:** Uses CMOS for internal logic to keep idle power consumption minimal. 3. **Speed:** Bipolar transistors at the output stage allow for very fast switching times, comparable to the 74F (Fast) series. 4. **Live Insertion:** ABT parts are often designed to support "hot-plugging" or live insertion into a powered backplane without damaging the bus. --- ### 4. Application Areas * **Bus Buffers:** Used to isolate different sections of a computer bus. * **Data Registers:** Temporary storage of 8-bit data in microprocessor systems. * **I/O Ports:** Acting as an interface between a CPU and peripheral devices. * **Memory Address Latching:** Holding addresses constant during memory access cycles.