TDK-Lambda’s New Digitally Controlled Power Supplies Meet Medical Specs
TDK-Lambda has introduced their new digitally controlled 300W power supplies that are designed specifically with medical applications in mind. With a 4kVac reinforced input to output isolation and other specifications such as an output-to-ground isolation of 1500Vac, the EFE300M meets the international safety standards of IEC 60601-1 for medical equipment, making it suitable for use in B and BF type medical applications. Regulated dc outputs of 12 or 24Vdc are standard and other voltages can be provided.
With a 3 x 6" footprint with less than a 1U profile (1.6" max), the EFE300M can be incorporated easily into designs where space is limited so end equipment can be smaller and cooler. Other features such as a redundant operation capability and a high current standby output make the EFE300M equally suitable for high integrity applications including broadcast, instrumentation, routers, servers and security networks, as well as, ATE, factory automation and mechatronics.
The EFE300M series includes an integrated magnetics transformer (transformer and inductor windings on the same core) to boost efficiency to typically 90% and employs an 8-bit microcontroller for full digital control of the output and to handle housekeeping routines. This resulted in a 25% parts count reduction to achieve a 45% smaller, and up to 56% lighter design when compared to similar competitive products. Power densities of up to 16.6W/in³ are achieved under peak load conditions and 12.5W/in³ under continuous loading.
TDK-Lambda’s control of the EFE300M allows the power supply’s performance, such as current limit and start-up characteristics, to be optimized digitally – this feature eliminates the hardware changes usually required in analog designs. A primary side control topology is used, supervised by the microcontroller. This is said to result in fewer parts and higher efficiency without sacrificing load regulation performance. Furthermore, the need for an opto-isolator is eliminated – a device which the company says is undesirable for long life power supply designs.
Additional features of the EFE300M include remote on/off and power-good signals; it also comes with a 5V/2A isolated standby supply, which is not affected by the remote on/off. The inclusion of an ORing FET allows redundant operation of EFE300M supplies with no external diodes required.
The EFE300M delivers 300W continuous power (400W peak for 10 seconds) with nominal outputs of 12V/25A or 24V/12.5A. However, non-standard output voltages can be accommodated easily by precise factory programming. An additional 12V/1A fan supply is also included and all models operate from 90 to 264Vac input with dual fusing as standard. Earth leakage current is less than 300µA at up to 264Vac, fully complying with medical safety requirements. Active power factor correction ensures EN61000-3-2 compliance. Other EMC improving design features include the use of SiC (silicon carbide) diodes that ensure Curve B EMC performance with a significant margin.
TDK-Lambda’s EFE300M is approved to IEC/EN/UL/CSA 60950-1 for general purpose applications, IEC/EN 61010-1 for laboratory and process control applications and, of course, IEC 60601-1 for medical equipment. In addition, the unit carries the CE mark according to the LV Directive and comes with a three-year warranty. The EFE300M is available in various configurations including: open-frame or L chassis, with or without an optional cover and a temperature-controlled fan.
The EFE300M series are available now with prices starting at $183.00 each in 500 piece quantities.
