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MU4 Series

For medical, industrial and test and measurement

Quiet by design, extremely low audible noise, up to 800W in 1U footprint

The MU4 series eliminates the need for additional power supplies and the extremely low audible noise enhances both patient and user experience.

  • 1U height, reduces the required system space and enables low profile design.
  • Extremely low noise level ensures both patients and users are not disturbed by excessive fan noise.
  • Thermally managed intelligent fan control* (IFC)
  • Ideal for medical, industrial and test and measurement applications.

* patent pending

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Simplifying system design with full MOPP isolation – including Body Floating (BF) applications

  • Full MOPP isolation, input to earth (1.5kVac), input to output (4kVac) and output to earth (1.5kVac)
  • Modular design offers known leakage current and EMC certified performance, this minimises or eliminates the need for additional EMI filters and further reduces the system cost and space required.
  • Up to 4 user-definable output channels each selectable from 5V to 104V for ultimate flexibility.
  • Remote monitoring and control via PMBusTM communication.

The TDK-Lambda Difference

MU4, with its intelligent fan control* (IFC), is quietly managing your system’s power needs, so you don't have to!

The MU4 utilises multipoint thermal measurement to monitor its internal temperature and manage the required airflow by adjusting the fan speed accordingly. As the fan RPM is directly related to audible noise, delivering the necessary airflow only when needed is key to low audible noise.

  • Under nominal conditions of 25°C, 80% load and 240Vac the fan rotates slowly producing less than 36dB** of audible noise.
  • Minimised fan noise improves patient and operator experience in medical and laboratory environments.
  • MU4, when peace and quiet matters most.

* patent pending
** configuration dependent

MU4, the only fan cooled 1U modular power supply with 1 x MOPP output to earth. Safety without compromise.

The medical equipment segment is rapidly evolving. Today's medical systems demand increasing complexity and reliability for improved patient care.

The flexibility of modular power design helps accelerate system development time and reduces design risk, enabling patients to benefit sooner

  • BF* rated, designed for easy system integration and compliance.
  • CB certified compliant to IEC/EN/UL 60601-1 and IEC/EN60601-1-2 4th Edition.
  • Suitable for medical, laboratory and industrial environments.

* BF - Body Floating

Helping to achieve your system compliance

TDK-Lambda MU4’s EMI performance is a combination of our design know-how - accumulated over decades - and thorough, meticulous evaluation.

MU4 achieves excellent margin to IEC/EN55011 Class B conducted and radiated emissions which provides easy integration for system engineers and equipment manufacturers.

  • EMI design validation is performed by in-house engineers at our state of the art EMI centre and backed up by independent regulatory approvals
  • IEC/EN60601-1-2 4th Edition compliant for emissions and immunity

- over 70 years of power supply design and manufacturing
- over 40 years of modular experience

In 1979, under the company name of Coutant Electronics Ltd., the world’s first 150 – 300W modular power supply – the ML series - was launched. Product evolution has seen the introduction of modular series covering 200 to 1500W, achieving many industry firsts and patents. A history underpinning TDK-Lambda’s position as the leading AC-DC modular power supply specialist.

The MU4 series continues this trend being the first 1U fan cooled modular with full MOPP isolation, (input and output to Earth and primary to secondary) and incorporating an intelligent fan control* (IFC).

* patent pending

Managing complex power problems with MU4 modular flexibility

  • Continuous output voltage coverage from 3.3Vdc – 104Vdc.
  • Parallel and series connected module options for increased power and output voltage.
  • Control of every output channel (enable/disable) and diagnostics via PMBusTM.
  • EMI/EMC certification for easy system integration.


Flexible for a wide variety of medical, industrial and diagnostic applications

Medical Equipment

MU4, FULL MOPP, is the heart of any Medical system

The Needs

IEC/EN/UL60601-1 medical systems demand reliability and quality from every system element, including the power supply. The power supply is at the heart of the system and therefore needs to be trusted to operate safely and reliably whenever needed.

Our Solutions

TDK-Lambda’s MU4 modular series is approved to the latest IEC/EN/UL60601-1 medical standards, ensuring compliance for the customers final application. The intelligent fan control is designed to ensure efficient and reliable operation i.e providing enhanced cooling only when necessary, minimising audible noise.

Our power experts are on hand to assist you with selecting and integrating any one of our medical grade power supplies into your system.

To demonstrate TDK-Lambda's quality and reliability, the MU4 has a 7 year warranty.

Factory Automation

Light weight and sturdy aluminium case for industrial applications

The Needs

Industrial technology covers an almost infinite range of applications. However they all share common requirements from their chosen power source. These include;

  • Safety: The power supply is the interface between the dangerous voltages of the mains supply and the low voltages used in the user/equipment interface.
  • Efficiency: Increasing factory automation brings 24/7 365 day operation. Therefore running costs need to be kept to a minimum.
  • Reliability: Often replacing failed power supplies costs more than the power supply itself (downtime, service engineer etc) and not forgetting the risk to reputation.

Our Solutions

Modular power supplies provide flexibility, using pre-built assemblies they can be configured to fulfil multiple customer output requirements with PMBusTM connectivity and pre-approved to safety & EMI standards.

By choosing the MU4, you know it is backed up by over 70 years of power experience. Every component has been individually selected and evaluated by a specialist TDK-Lambda components team.

All design validation and safety pre-approvals have been performed by in-house engineers at our state-of-the-art EMC and DVT centres and backed up by independent regulatory approvals.

Test & Measurement

Low EMI and audible noise supporting sensitive environments

The Needs

Test and measurement covers many applications including mass spectrometry, blood/tissue analysis and many types of automated test equipment (ATE) for factory automation. In these critical and demanding environments reliability is paramount. Just as important, invisible electro-magnetic noise that all electronic equipment emit, including power supplies, should not interfere with sensitive measuring and analysis equipment

Our Solutions

With a range of output voltages (3.3Vdc to 104Vdc), PMBusTM communication and TDK-Lambda's quality and reliability, the MU4 provides the solution for a wide range of applications. The MU4's impressive EMI performance betters Class B requirements reducing implementation costs in sensitive environments.

Modified Standard and Power+ Solutions

The Needs

We understand that there is never a one size fits all solution. This could mean your application requires:

  • Non-standard voltages
  • Cable looms & connectors
  • Ruggedisation for shock, vibration, high G and outdoor environments

Or you just have an idea how to make integration easier or simpler.

Our Solutions

Our power experts are here to listen and discuss how best to realise your requirements, whether it is a modification to a standard product or a full custom design to your specification.

So before looking anywhere else, challenge us.

Technical Data

Output Power 600 - 800W
Number of outputs including standby supply 1 - 5
Output Voltage 3.3 – 104Vdc
Input Voltage 85 – 264Vac
Size (W x H x L) 89 x 41 x 254mm
Warranty 7 Years
Cooling Options Air flowFan
Efficiency: up to 90%

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Additional Material

MU4 Overview Video

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