The **M3H28TBD-R** is a high-performance, radiation-hardened (Rad-Hard) isolated DC-DC converter specifically designed for space and satellite applications. It is manufactured by **Infineon Technologies** (formerly IR HiRel). --- ### ## 1. Technical Specifications The M3H series is known for its high efficiency and reliability in extreme environments. | Feature | Specification | | :--- | :--- | | **Input Voltage Range** | 18V to 50V DC (28V Nominal) | | **Output Power** | Up to 40 Watts | | **Configuration** | Triple Output (T) | | **Isolation** | Magnetic coupling (Input to Output) | | **Efficiency** | ~80% to 83% (depending on load) | | **Operating Temp** | -55°C to +125°C | --- ### ## 2. Key Electronic Components & Architecture The internal circuitry of the M3H28TBD-R utilizes a sophisticated power stage to ensure stability against radiation effects: * **Forward Converter Topology:** It typically uses a single-ended forward topology with resonant reset to minimize switching losses. * **Radiation Hardened MOSFETs:** The internal power switches are Rad-Hard MOSFETs that are resistant to **Single Event Effects (SEE)**. * **Magnetic Feedback:** To maintain electrical isolation while providing precise regulation, it uses a magnetic feedback loop rather than optocouplers (which degrade quickly under radiation). * **EMI Filtering:** The unit includes internal thick-film ceramic capacitors and inductors to reduce conducted emissions and susceptibility. --- ### ## 3. Radiation Performance This part is categorized as "Space Grade," meaning it is tested to withstand the harsh vacuum and radiation belts. * **TID (Total Ionizing Dose):** Guaranteed performance up to **100 krad(Si)**. * **SEE (Single Event Effects):** Rated for Linear Energy Transfer (LET) up to **82 MeV·cm²/mg**. * **No Derating:** Designed so that electronic parameters remain within spec even after the full radiation dose is absorbed. --- ### ## 4. Application Context The "TBD" in the part number indicates the specific voltage configuration for the triple outputs. Generally, these are used to power: 1. **Digital Logic:** FPGAs and Microprocessors. 2. **Analog Circuitry:** Operational amplifiers and sensors. 3. **Telemetry Systems:** Communication equipment on satellites. --- ### ## 5. Physical Packaging The device is housed in a **hermetically sealed**, low-profile package. * **Construction:** Thick-film hybrid technology. * **Sealing:** Seam-welded to prevent outgassing in a vacuum. * **Weight:** Approximately 110 grams.