DC/DC Front-end Filters: EMI Filter + Transient Protector

The MCF series complies with the requirements of MIL-STD 1275D (Characteristic of 28 volt DC electrical systems in military vehicles) and MIL-STD 461 (Requirement for the control of electromagnetic interference characteristics of subsystems and equipment). This filter series accepts 9-36Vdc input voltage (50Vdc for 1 sec.) which is suitable for military vehicle with 28V bus systems respectively 24V bus systems. They are also applicable for both heavy industrial and rolling stock applications.

block diagram front end filters - EMI filter and protection

The MCF series offers active input over-voltage protection which clamps over-voltages for maximum 50ms up to 100V to a safe level of 40V and absorbs +/-250V spikes with the internal protection circuits. By connecting the MCF module with a few additional MLCCs, its internal EMI filter meets MIL-STD 461G limits. Besides, it also features other active protection functions for an advanced protection of the DC/DC converter module such as remote on/off control, overload protection, output short-circuit protection, reverse polarity protection, inrush current limitation, etc.

Active Surge Voltage Protection

The MCF filter module is a fully integrated front-end module. In addition to complying with MIL-STD 1275D and MIL-STD 461G, it also fulfills the EN 50155, RIA 12 and NF F 01-510 standards for rolling stock 24V bus systems. It greatly reduces the time to design the EMI-filter and peripheral circuits, save system space and provide a comprehensive system protection. The MCF filters meet the environmental MIL-STD 810F specification for shock and vibration. The operating temperature range of -40°C to 105°C (optionally -55°C) allows to use these MCF filters with P-Duke DC/DC converters in a wide range of demanding applications.


Operating input voltage range9-36VDC
Inrush currentWith 1000μF connected to the output5A
Start up voltage9VDC
Transient voltage1 second, max.50VDC
50 ms, max.100VDC
Spikes70μs , 15mJ(-)250to (+)250VDC
Reverse polarity protectionInternal series MOSFET is held in an off state to avoid reverse current flow(-)36VDC
Output voltageVin-1 – Vin VDC
Clamping voltageInput transient voltage mode40VDC
Output current15A
Output power range250W
Over load protectionHiccup mode35A
Short circuit protectionContinuous, automatics recovery


StandardUn(VDC)Permanent Operating Input Range (VDC)BrownoutTransientSpike
MIL-STD-1275D2823 – 33n/a40V / 500ms±250V / 70μs
100V / 50ms
EN 501552416.6 – 3014.4V / 100ms33.6V / 1000msn/a
RIA122416.6 – 3014.4V / 100ms36V / 1000msn/a
84V / 20ms
NF F 01-5102418 – 3412V / 100ms40V / 100msn/a

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Selecting the right power supply for your application is not a small task. Let our technical sales engineers guide you through the process of choosing the right solution for your needs.

Below some parameters usually required to size and select the right power supply:

  • Power & control requirements
  • Output & Input Voltage / Multioutput Voltage / Variable Voltage
  • Redundancy level
  • Mounting
  • Inrush Current
  • Environmental specifications (Temperature, altitude, vibration, shock)
  • Specific Industries Standards (Railway, Military, Medical)
  • Terminals

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