### Overview of the SN74HC393D The **SN74HC393D** is a high-speed CMOS device featuring dual 4-bit binary counters. It is widely used in digital electronics for frequency division, timing, and counting applications. --- ### Technical Specifications The following table summarizes the key electrical and physical characteristics of the SN74HC393D: | Parameter | Specification | | :--- | :--- | | **Logic Family** | HC (High-speed CMOS) | | **Function** | Dual 4-Bit Binary Counter | | **Operating Voltage (Vcc)** | 2.0V to 6.0V | | **Package Type** | SOIC-14 (Small Outline Integrated Circuit) | | **Max Frequency (at 6V)** | ~35 MHz | | **Current Consumption** | 40 µA (Static) | | **Operating Temperature** | -40°C to +85°C | --- ### Internal Architecture and Pinout The IC contains two independent 4-bit counters. Each counter has an individual **Clock (CP)** input and a **Master Reset (MR)** input. #### Pin Configuration Table | Pin Number | Symbol | Function | | :--- | :--- | :--- | | 1 | 1CP | Clock Input, Counter 1 (Negative edge triggered) | | 2 | 1MR | Master Reset, Counter 1 (Active High) | | 3, 4, 5, 6 | 1Q0 - 1Q3 | Parallel Outputs, Counter 1 | | 7 | GND | Ground (0V) | | 8, 9, 10, 11| 2Q3 - 2Q0 | Parallel Outputs, Counter 2 | | 12 | 2MR | Master Reset, Counter 2 (Active High) | | 13 | 2CP | Clock Input, Counter 2 (Negative edge triggered) | | 14 | VCC | Supply Voltage | --- ### Key Features * **Dual Functionality:** Contains two separate counters that can be used independently or cascaded to form an 8-bit counter. * **Negative-Edge Triggering:** The counter increments on the High-to-Low transition of the clock signal, which helps prevent false triggering from noise. * **Asynchronous Reset:** A logical High on the Master Reset (MR) pin immediately overrides the clock and resets all four output bits to Low (0000). * **High Noise Immunity:** As a CMOS device, it offers excellent resistance to electrical noise. --- ### Application Example: 8-Bit Counter To create an 8-bit counter, you connect the output of the first 4-bit counter to the clock input of the second. ```markdown Counter 1 (LSB) -> Q3 Output (Pin 6) | v Counter 2 (MSB) -> CP Input (Pin 13) ``` ---