TDK-Lambda News

Taking digital control to the next level, TDK-Lambda’s revolutionary EFE Series of embedded frontend power supplies delivers industry leading power density, high efficiency and enhanced reliability. The first products in the range are the 300W EFE-300 and the 400W EFE-400 single output supplies that deliver 133% peak power capability for 10 seconds and offer a class leading efficiency of up to 90%.

The EFE Series employs an 8-bit microcontroller for full digital control of the output and to handle housekeeping routines This brings a 25% parts count reduction to achieve a 45% smaller and up to 56% lighter design when compared to similar recently announced competitive products. Power densities of up to 22W/in3 are achieved under peak load conditions and 16.6W/in3 under continuous loading.

TDK-Lambda’s European Marketing Director, Martin Southam commented: ‘’This is the breakthrough that marks a new inflexion point in the power supply industry. Our UK design team have created revolutionary core IP that will spread rapidly across our product roadmap.‘”

Compact dimensions and a 1U profile (the EFE-300 is only 127mm x 76mm x 34mm and the EFE-400 is only 152mm x 76mm x 34mm) allow the EFE Series to be incorporated in designs where space is limited, so end equipment can be smaller, cooler and more feature rich. Typical markets include broadcast, instrumentation and industrial, and other applications, such as ATE, automation, routers, servers and security networks.


The new digitally controlled power supplies incorporate many innovative design features including an integrated magnetics transformer that increases efficiency by up to 1%. The digital control allows the power supply’s performance, such as current limit and start-up characteristics, to be optimised. A low cost primary side control topology is used, supervised by the microcontroller. This results in fewer parts and higher efficiency without sacrificing load regulation performance. Furthermore, the need for an opto-isolator is eliminated – a device which is undesirable for long life power supply designs.

TDK-Lambda UK’s Advanced Development Manager, Andrew Skinner commented: ‘’Many of the design features of the EFE Series directly enhance reliability. For example, having precise control of abnormal situations through proprietary algorithms prevents device overstress. In addition, better circuit noise immunity is achieved compared to analogue designs, and the substantial parts count reduction allows for more optimised component spacing leading to improved thermal performance.”

The EFE-300 delivers 300W continuous power (400W peak for 10 seconds) with nominal outputs of 12V / 25A or 24V / 12.5A, and the EFE-400 delivers 400W continuous power (530W peak for 10 seconds) with nominal outputs of 12V / 33.3A or 24V / 16.7A. All models can be precisely factory programmed to accommodate non-standard system voltages. An additional 12V / 0.25A fan supply is also available and all models operate from 90 - 264VAC input with dual fusing as standard. Active power factor correction ensures EN61000-3-2 compliance. Other EMC improving design features, such as the use of SiC diodes, ensure curve B EMC performance with a significant margin.

As well the impressive technical performance, the EFE Series meets TDK-Lambda’s design brief for environmentally responsible products by consuming less energy in manufacture and use, having fewer parts, weighing less and having a long life expectancy .

The EFE Series is available in a variety of case options, either open frame or enclosed. The use of low profile output connectors allows maximum airflow for optimised cooling efficiency.

All products in TDK-Lambda’s EFE Series are approved to IEC/EN/UL/CSA 60950-1 for general purpose applications and IEC/EN 61010-1 for laboratory and process control applications. In addition, the units carry the CE mark according to the LV Directive and come with a three-year warranty.