The **M3H57FBD-R** is a high-reliability, radiation-hardened DC-DC converter module developed by **Moog Inc.** (formerly Ethos/VPT). It is specifically designed for space applications, including satellites and planetary probes. --- ### 1. Key Technical Specifications The M3H series is known for its high efficiency and hybrid circuit construction. | Parameter | Specification | | :--- | :--- | | **Input Voltage Range** | 18V to 50V DC (Typical 28V) | | **Output Voltage** | 5V DC (Fixed) | | **Output Power** | Up to 15 Watts | | **Topology** | Forward Converter (Fixed Frequency) | | **Operating Temp** | -55°C to +125°C | | **Radiation Hardness** | TID (Total Ionizing Dose) up to 100 krad(Si) | --- ### 2. Core Electronic Components & Architecture The module is a "Hybrid," meaning it combines discrete components with bare die technology on a ceramic substrate. #### A. Power Stage * **MOSFETs:** Utilizes radiation-hardened power MOSFETs to manage high-speed switching without degradation from heavy ions. * **Magnetic Components:** Custom-designed planar or toroidal transformers provide galvanic isolation and voltage scaling while maintaining a low profile. #### B. Control & Feedback * **PWM Controller:** A radiation-hardened Pulse Width Modulation (PWM) IC regulates the duty cycle based on the load. * **Optoisolators / Magnetic Feedback:** Uses radiation-tolerant feedback mechanisms to maintain output regulation without physical electrical connection between input and output. #### C. Filtering and Protection * **EMI Filters:** Internal LC filters are integrated to reduce conducted emissions and susceptibility. * **Protection Circuits:** Includes Under-Voltage Lockout (UVLO), Output Over-Voltage Protection, and Short Circuit protection. --- ### 3. Materials and Packaging The "FBD" in the part number often refers to the package style and screening level. * **Hermetic Seal:** The unit is housed in a seam-welded, hermetically sealed metallic package to prevent outgassing in vacuum environments. * **Internal Interconnects:** Uses gold-plated leads and alumina ceramic substrates for thermal conductivity and electrical insulation. --- ### 4. Space-Grade Features * **SEE/SEL Immunity:** Designed to be immune to Single Event Effects (SEE) and Single Event Latch-up (SEL) up to 80 MeV-cm²/mg. * **Screening:** Tested according to MIL-PRF-38534 Class H or K standards.