The **HC393D** is a high-speed CMOS (Complementary Metal-Oxide-Semiconductor) integrated circuit. Specifically, it is a **Dual 4-Bit Binary Ripple Counter**. Below is a detailed breakdown of its electronic specifications and functions. --- ### 1. General Overview The "HC" in the name signifies **High-speed CMOS** logic, meaning it is compatible with standard CMOS logic levels while operating at speeds similar to older TTL (Transistor-Transistor Logic) components. The "D" suffix typically refers to the package type, most commonly an **SOIC-14** (Small Outline Integrated Circuit). ### 2. Key Specifications | Parameter | Typical Value | | :--- | :--- | | **Supply Voltage (Vcc)** | 2.0V to 6.0V | | **Operating Temperature** | -40°C to +85°C (Standard) | | **Frequency (at 6V)** | Up to 50 MHz | | **Logic Family** | 74HC | | **Package Type** | SOIC-14 (Surface Mount) | | **Number of Counters** | 2 Independent Counters | ### 3. Pinout Configuration The HC393D contains two separate 4-bit counters (8 bits total if cascaded) within a single 14-pin package. | Pin Number | Symbol | Function | | :--- | :--- | :--- | | 1 | 1CP | Clock Input (Counter 1) - Triggered on High-to-Low transition | | 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) | | 14 | Vcc | Positive Supply Voltage | --- ### 4. Functional Operation * **Ripple Counting:** This is an asynchronous counter. The clock pulse only triggers the first flip-flop (Q0). Each subsequent stage is triggered by the preceding stage. While this is simple, it introduces a small cumulative delay (ripple) across the bits. * **Counting Range:** Each 4-bit section can count from `0000` to `1111` (binary) or 0 to 15 (decimal). * **Cascading:** By connecting the output of the first counter (1Q3) to the clock input of the second counter (2CP), the device becomes an **8-bit counter**, capable of counting from 0 to 255. * **Master Reset (MR):** When the MR pin is pulled HIGH, all outputs (Q0-Q3) for that specific counter are immediately set to LOW, regardless of the clock input. --- ### 5. Common Applications * **Frequency Division:** Dividing a high-frequency clock signal into lower, usable frequencies. * **Time Delays:** Creating specific timing intervals in digital circuits. * **Event Counting:** Keeping track of pulses or triggers from sensors. * **Digital Clocks:** Used in the logic stages to count seconds, minutes, or hours. ---