# Technical Overview: U74LVC574G-P20-R The **U74LVC574G-P20-R** is a high-performance, low-voltage CMOS octal D-type flip-flop. It is designed for low-voltage (1.65V to 3.6V) operation with the capability of interfacing with 5V systems. --- ## 1. Key Specifications | Parameter | Specification | | :--- | :--- | | **Logic Family** | LVC (Low Voltage CMOS) | | **Function** | Octal D-Type Flip-Flop (Edge-Triggered) | | **Output Type** | 3-State (Tri-state) | | **Operating Voltage ($V_{CC}$)** | 1.65V to 3.6V | | **Input Tolerance** | 5V tolerant inputs | | **Output Drive ($I_{OH}/I_{OL}$)** | $\pm$24 mA at 3.0V | | **Package Type** | TSSOP-20 (indicated by P20) | | **Packing** | Tape & Reel (indicated by -R) | --- ## 2. Functional Description The device consists of eight edge-triggered D-type flip-flops. On the positive transition of the **Clock (CLK)** input, the $Q$ outputs are set to the logic states that were setup at the **Data (D)** inputs. ### Control Pins * **Output Enable ($\overline{OE}$):** When $\overline{OE}$ is LOW, the 8 outputs are active. When $\overline{OE}$ is HIGH, the outputs are placed in a high-impedance (Hi-Z) state. * **Clock (CLK):** Information from the D inputs is transferred to the Q outputs on the positive-going edge of the clock pulse. ### Truth Table | Inputs ($\overline{OE}$) | Inputs (CLK) | Inputs (D) | Output (Q) | | :---: | :---: | :---: | :---: | | L | $\uparrow$ | H | H | | L | $\uparrow$ | L | L | | L | L/H/$\downarrow$ | X | $Q_0$ (No Change) | | H | X | X | Z (High Impedance) | --- ## 3. Notable Features ### 5V Tolerance One of the most critical features of the LVC family is that the inputs are 5V tolerant even when the device is powered at 3.3V. This allows it to act as a **level shifter** in mixed-voltage systems. ### High-Drive Capability With a $\pm$24 mA output drive, this chip is capable of driving heavily loaded backplanes or high-speed memory buses without significant signal degradation. ### Power-Down Mode ($I_{off}$) The device supports partial-power-down mode operation. The $I_{off}$ circuitry disables the outputs, preventing damaging current backflow through the device when it is powered down. --- ## 4. Typical Applications * **Buffer Registers:** Temporary storage of data between a CPU and a peripheral. * **Bus Drivers:** Driving data lines in multi-drop bus architectures. * **I/O Ports:** Expanding the output capabilities of microcontrollers. * **Voltage Translation:** Moving signals from 5V logic levels to 3.3V logic levels.