The **MH28FCG-R** is a specific type of high-reliability, radiation-hardened DC-DC converter, typically manufactured by **Crane Aerospace & Electronics (Interpoint)**. These components are designed for extreme environments, such as aerospace, satellite systems, and defense applications. --- ## 1. Core Technical Specifications The MH28 series is known for its compact size and high power density. Below are the primary electrical characteristics for the **MH28FCG-R** model: | Parameter | Specification | | :--- | :--- | | **Input Voltage Range** | 16V to 40V DC (28V Nominal) | | **Output Voltage** | 5V DC | | **Output Power** | Up to 15 Watts | | **Efficiency** | ~75% to 80% | | **Isolation** | 100MΩ @ 500VDC | | **Operating Temp** | -55°C to +125°C | | **Package Style** | Flanged, Hermetically Sealed Metal Case | --- ## 2. Key Internal Electronic Components The device is a sophisticated hybrid circuit rather than a single chip. It contains several functional stages: ### A. Input Filter Stage * **Inductors and Capacitors:** Used to suppress EMI (Electromagnetic Interference) and handle input surges. * **Undervoltage Lockout (UVLO):** Circuitry that prevents the converter from operating if the input voltage is too low to maintain regulation. ### B. Power Conversion Stage * **PWM Controller:** A Pulse Width Modulation controller that regulates the output by switching the primary MOSFET. * **Power MOSFETs:** High-speed switches that convert DC to high-frequency AC for the transformer. * **Isolation Transformer:** Provides galvanic isolation between the input (28V) and output (5V) side. ### C. Feedback and Regulation * **Optocoupler or Magnetic Feedback:** Used to send a signal from the output side back to the input controller to maintain a steady 5V, even as the load changes. * **Schottky Rectifiers:** Used on the output side for low-voltage drop rectification. --- ## 3. The "R" Suffix: Radiation Hardness The **-R** in the part number is critical. It signifies that the internal electronics are **Radiation Hardened**. 1. **TID (Total Ionizing Dose):** Components are tested to withstand high levels of radiation (often up to 100k rads) without performance degradation. 2. **SEE (Single Event Effects):** The design is hardened against "latch-up" or "burnout" caused by heavy ions or protons in space environments. --- ## 4. Typical Applications Due to its high reliability and "Flight Heritage," this part is used in: * **Satellite Bus Power:** Providing regulated 5V for onboard computers. * **Launch Vehicles:** Powering telemetry units. * **Military Aircraft:** Used in mission-critical avionics where power failure is not an option. ---