The **MQME-270-R** is a high-reliability, radiation-hardened DC-DC converter specifically designed for space and satellite applications. It is manufactured by **Micropac Industries** (originally under the VPT, Inc. brand line for space heritage). Below is a detailed breakdown of its electronic specifications and features. --- ## 1. Core Technical Specifications The MQME series is characterized by its high power density and ability to withstand the harsh environment of Earth's orbit. | Feature | Specification | | :--- | :--- | | **Input Voltage (Nominal)** | 270 VDC | | **Input Voltage Range** | 160 VDC to 400 VDC | | **Output Power** | Up to 120 Watts | | **Efficiency** | Up to 90% | | **Operating Temperature** | -55°C to +125°C | | **Isolation** | 500V Input to Output / Input to Case | --- ## 2. Key Electronic Features ### A. Power Conversion Topology The device utilizes a **Fixed Frequency Magnetic Isolated Flyback/Forward** topology (depending on the specific sub-configuration). This ensures stable performance across varying loads and minimizes Electromagnetic Interference (EMI). ### B. Radiation Hardness (Space Grade) The "R" suffix typically denotes specific radiation performance levels. These parts are designed to survive: * **TID (Total Ionizing Dose):** Usually rated for 100 krad(Si). * **SEE (Single Event Effects):** Immune to Single Event Latch-up (SEL) and designed to minimize Single Event Upset (SEU) impacts up to high LET (Linear Energy Transfer) levels. ### C. Protection Circuitry The internal electronics include several layers of protection to prevent failure of the satellite's power bus: * **Over-Voltage Protection (OVP):** Clamps output if it exceeds safe limits. * **Short Circuit Protection:** Current limiting with automatic recovery. * **Under-Voltage Lockout (UVLO):** Ensures the converter does not attempt to start until the input voltage is high enough for stable operation. --- ## 3. Package and Interface The MQME-270-R is housed in a hermetically sealed, low-profile package to ensure longevity in a vacuum. * **Case Material:** Steel or Aluminum with Gold plating. * **Lead Finish:** Gold-plated or Solder-dipped options. * **Control Pins:** Includes pins for **Remote Sense**, **Output Trim**, and **Inhibit** (to turn the unit on/off electronically). --- ## 4. Typical Applications 1. **Low Earth Orbit (LEO) Satellites:** High efficiency for power-constrained platforms. 2. **Geostationary (GEO) Satellites:** Long-term radiation resistance for missions lasting 15+ years. 3. **Deep Space Probes:** Wide input voltage tolerance for varying battery/solar conditions.