The **U74LVC573G-R20-R** is a high-performance CMOS octal transparent latch featuring 3-state outputs. It is commonly used in bus-oriented applications where high speed and low power consumption are required. --- ## 1. Technical Specifications The following table summarizes the key electrical and physical characteristics of the component: | Parameter | Value / Description | | :--- | :--- | | **Logic Family** | LVC (Low Voltage CMOS) | | **Function** | Octal Transparent D-Type Latch | | **Number of Bits** | 8-bit | | **Output Type** | 3-State (High Impedance mode supported) | | **Supply Voltage ($V_{CC}$)** | 1.65V to 3.6V | | **Input/Output Logic Levels** | 5V Tolerant inputs (allows voltage translation) | | **Output Drive Current** | $\pm24$ mA (at $V_{CC} = 3.0V$) | | **Propagation Delay** | ~6.4 ns (Max at 3.3V) | | **Operating Temperature** | -40°C to +85°C | --- ## 2. Pin Configuration and Functions The device is typically housed in a 20-pin package (such as SSOP or TSSOP, denoted by "R20" in the part number). * **D0 – D7 (Inputs):** Data inputs for the 8 latches. * **Q0 – Q7 (Outputs):** Data outputs. * **LE (Latch Enable):** When HIGH, the latches are transparent (outputs follow inputs). When LOW, the data is latched. * **$\overline{OE}$ (Output Enable):** When LOW, outputs are active. When HIGH, outputs are in a high-impedance state (Z). * **$V_{CC} / GND$:** Power supply and ground pins. --- ## 3. Key Functional Features ### A. Voltage Translation One of the most important features of the LVC family is that the inputs are **5V tolerant**. This means the chip can be powered at 3.3V while receiving signals from a 5V logic system, acting as a level shifter. ### B. 3-State Outputs The 3-state capability allows multiple device outputs to be connected to the same bus lines. When the Output Enable ($\overline{OE}$) pin is pulled high, the outputs effectively disconnect from the bus, preventing signal contention. ### C. Transparent Mode While the Latch Enable (LE) is high, the device acts like a buffer. The moment LE transitions to low, the data present at the inputs at that specific time is "frozen" or stored in the latch. --- ## 4. Typical Applications * **Address Latches:** Used in microcontroller systems to separate multiplexed address/data buses. * **I/O Expansion:** Increasing the number of output ports on a CPU. * **Bus Drivers:** Driving heavily loaded backplanes or memory arrays. * **Signal Buffering:** Isolating different sections of a digital circuit. ---