The **HCS166KMSR** is a high-reliability, radiation-hardened (RadHard) electronic component. Specifically, it is an **8-Bit Parallel-In/Serial-Out Shift Register** designed for extreme environments, such as aerospace, satellite systems, and military applications. Below is a detailed breakdown of its electronic characteristics and technical specifications. --- ### 1. Functional Overview The HCS166KMSR is a 16-pin integrated circuit (IC) that allows data to be loaded in parallel (8 bits at once) and shifted out serially. This is vital for reducing the number of wires needed for data transmission in complex systems. | Feature | Description | | :--- | :--- | | **Logic Family** | High-Speed CMOS (HCS) | | **Logic Type** | 8-Bit Shift Register (Parallel-In, Serial-Out) | | **Clocking** | Synchronous loading and shifting | | **Reset** | Asynchronous Master Reset | --- ### 2. Key Technical Specifications This part is engineered for high performance under thermal and electrical stress. | Parameter | Specification | | :--- | :--- | | **Supply Voltage ($V_{CC}$)** | 2.0V to 6.0V | | **Radiation Tolerance (TID)** | Typically up to 300k rad(Si) | | **Operating Temperature** | -55°C to +125°C | | **Package Type** | Ceramic Flatpack (K-Suffix) | | **Burn-in** | 100% Screened to MIL-STD-883 standards | --- ### 3. Pin Configuration and Logic The device operates using specific control signals to determine how data moves through the internal flip-flops. #### Pin Functions: * **$D_0$ - $D_7$**: Parallel data inputs. * **SER**: Serial data input (for cascading multiple registers). * **CLK / CLK INH**: Clock and Clock Inhibit inputs. * **SH/LD**: Shift/Load control (Low = Load Parallel; High = Shift Serial). * **MR**: Master Reset (Active Low). * **$Q_7$**: The serial output bit. --- ### 4. Radiation Hardening Features The "MSR" and "KMSR" designations indicate specific screening for space-grade reliability: 1. **Single Event Upset (SEU) Immunity**: Designed to prevent bit-flips caused by cosmic rays. 2. **Latch-up Immunity**: The CMOS structure is modified (often using Silicon-on-Sapphire or specific epitaxial layers) to prevent permanent destruction from high-energy particles. 3. **Post-Radiation Performance**: It maintains its switching speeds and leakage current limits even after significant radiation exposure. --- ### 5. Application Example (Pseudocode) In a satellite control system, you might interface this with a microcontroller to read 8 sensor states using only 3 wires (Clock, Data, Load). ```c // Example: Reading data from HCS166 digitalWrite(LD_PIN, LOW); // Capture 8-bit parallel input delayMicroseconds(1); digitalWrite(LD_PIN, HIGH); // Switch to Serial Shift mode for(int i=0; i<8; i++) { dataBit[i] = digitalRead(SER_OUT_PIN); // Read bit pulseClock(); // Shift to next bit } ``` ---