The **M3EH28XPA-R** is a high-reliability, radiation-hardened (Rad-Hard) DC-DC converter module typically manufactured by **Crane Aerospace & Electronics (Interpoint)**. These modules are specifically designed for space applications, satellites, and high-altitude aerospace systems. --- ### 1. General Specifications The part belongs to the **M3EH Series**, which is characterized by its triple output configuration and high power density. | Feature | Specification | | :--- | :--- | | **Input Voltage Range** | 18V to 50V DC (28V Nominal) | | **Output Power** | Up to 15 Watts (Total) | | **Number of Outputs** | Triple (3) | | **Operating Temperature** | -55°C to +125°C | | **Efficiency** | ~75% to 80% (Typical) | | **Package Type** | Hermetically sealed metal case | --- ### 2. Breakdown of the Part Number The alphanumeric code provides specific details regarding the configuration and screening level of the component: * **M3EH**: Series identifier (Triple output, high-reliability series). * **28**: Nominal input voltage (28 Volts). * **X**: Standard placeholder for output voltage configuration. * **PA**: Specific output voltage combination (typically +5V and ±12V or ±15V depending on the exact datasheet mapping). * **-R**: Radiation Hardness Assurance (RHA) level. This indicates the component is tested for Total Ionizing Dose (TID), often up to 100 krad(Si). --- ### 3. Key Electronic Characteristics #### A. Power Management & Regulation * **Galvanic Isolation:** Provides magnetic isolation between the input and output stages to prevent ground loops and protect sensitive loads. * **Fault Protection:** Includes integrated features such as over-current protection (short-circuit protection) and under-voltage lockout (UVLO). * **Inhibit Function:** Allows the converter to be turned on or off via a logic signal to conserve system power. #### B. Radiation Hardness Unlike commercial converters, the "R" suffix indicates that the internal semiconductors and circuitry are designed to survive: * **TID (Total Ionizing Dose):** Degradation over long-term exposure to radiation. * **SEE (Single Event Effects):** Resistance to sudden malfunctions caused by heavy ions or protons (Latch-up, Burnout). #### C. EMI Filtering While the module has internal filtering, it is often paired with an external EMI filter (like the SFME series) to meet rigorous military standards such as **MIL-STD-461**. --- ### 4. Typical Application Circuit The module is integrated into a system using a series of pins for input, output, and control: ```c [Input Source 28V] ----> [EMI Filter] ----> [M3EH28XPA-R] ----> [Output 1: +5V Digital] | +-----> [Output 2: +15V Analog] | +-----> [Output 3: -15V Analog] ``` ---