Content last revised on October 25, 2025.
MDD26-14N1B | 1400V Dual Diode Module Engineered for High-Reliability Power Conversion
The MDD26-14N1B is a dual diode module engineered for robust thermal management and high electrical integrity in demanding power rectification circuits. It combines key specifications of 1400V | 36A | 3600 V~ Isolation into a standard TO-240AA package, delivering superior thermal performance and a significant electrical safety margin. This module directly addresses the need for durable components in industrial systems operating on 480V AC lines by providing ample voltage headroom to withstand line transients. For industrial power supplies where operational uptime is critical, the MDD26-14N1B's thermally efficient and high-isolation design provides a dependable foundation.
Key Parameter Overview
Decoding Specifications for Thermal and Electrical Robustness
The technical specifications of the MDD26-14N1B are optimized for performance and longevity in industrial power applications. The parameters are grouped by function to facilitate a clear evaluation for your design requirements.
| Parameter | Symbol | Value | Unit |
|---|---|---|---|
| Blocking Characteristics | |||
| Repetitive Peak Reverse Voltage | VRRM | 1400 | V |
| Forward Characteristics | |||
| Average Forward Current (180° sine) | IFAVM | 36 | A |
| RMS Forward Current (per diode) | IFRMS | 60 | A |
| Peak Forward Surge Current (10 ms, 50 Hz, TVJ=45°C) | IFSM | 650 | A |
| Thermal and Mechanical Characteristics | |||
| Operating Junction Temperature Range | TVJ | -40 to +150 | °C |
| Isolation Voltage (50/60 Hz, RMS) | VISOL | 3600 | V~ |
This table presents a selection of key parameters. It is not exhaustive.
Download the MDD26-14N1B datasheet for detailed specifications and performance curves.
Application Scenarios & Value
Achieving System-Level Reliability in Industrial Power Rectification
The MDD26-14N1B is an optimal component for uncontrolled rectifiers in a wide range of industrial equipment. What is the primary benefit of its high voltage rating? Enhanced system durability in electrically noisy environments. In a classic use case, such as the front-end rectifier for a Variable Frequency Drive (VFD) operating on a 480V three-phase line, the 1400V VRRM provides a substantial safety margin against voltage spikes and transients common in industrial plants. This headroom is critical for preventing device failure and ensuring the longevity of the entire drive system.
The module's construction, featuring a Direct Copper Bonded (DCB) Al2O3 ceramic base plate, provides excellent electrical isolation and efficient heat dissipation. This is crucial for maintaining a stable DC bus voltage under heavy loads. Think of the DCB substrate as a dedicated, high-efficiency conduit for heat, pulling it away from the silicon chip and transferring it to the heatsink. This efficient thermal pathway helps prevent the diodes from overheating, a primary cause of premature failure in power conversion systems. While the MDD26-14N1B is well-suited for applications requiring up to 36A, for systems demanding higher current handling in a similar package, the MDD95-12N1B is an available alternative.
Technical Deep Dive
The Engineering Behind a 3600V Isolation Voltage
The isolation voltage (VISOL) of 3600V~ is a defining feature of the MDD26-14N1B, directly contributing to system safety and reliability. This high isolation capability is achieved through the use of a Direct Copper Bonded (DCB) aluminum oxide (Al2O3) ceramic substrate. This design creates a robust dielectric barrier between the electrically live semiconductor chips and the module's metal baseplate, which is typically mounted to a grounded heatsink. For a system designer, this simplifies compliance with safety standards like UL and IEC, as the module itself provides a certified, high-integrity isolation barrier. This built-in isolation reduces the need for external insulating materials and complex mounting procedures, streamlining the assembly process and minimizing potential points of failure.
Frequently Asked Questions (FAQ)
How does the 3600V~ isolation voltage of the MDD26-14N1B benefit my system design?
The high isolation voltage provides a superior safety margin, ensuring robust electrical separation between the power circuit and grounded chassis components. This simplifies meeting stringent industrial safety regulations, enhances overall system reliability by preventing arc-over events, and can reduce the complexity and cost of system-level insulation schemes.
What is the significance of the planar passivated chip technology used in this module?
Planar passivated chips feature a protective layer over the semiconductor junctions. This process results in very stable and low reverse leakage currents, especially at elevated temperatures. For the end application, this translates into higher efficiency (less wasted energy) and increased reliability, as it makes the device less susceptible to degradation over its operational life.
