New Industry Products

TDK’s Series of 350W Convection Cooled Medical Power Supplies Can Deliver Peak Power of up to 1,000W

July 13, 2021 by Gary Elinoff

In addition to offering either 24, 30, 36, or 48 volts, all four members of the series provide a 5-volt, 0.3A isolated standby voltage output.

TDK’s CUS350MP series of medical power supplies’ ability to deliver higher peak power allows designers to skip the added expense of larger power supplies to contend with occasional elevated power demands.

TDK’s Open-Frame CUS350MP series. Image courtesy of TDK

This series of medical power supplies feature a range of medical and industrial safety certificates. They operate over an input range of 85 to 265 VAC, at 47 to 63 Hz. At 230VAC, they deliver a full load operating efficiency of 94%. They can also be supplied by DC power, over a voltage range of 120 to 370 VDC, but TDK cautions that the units aren’t safety certified for DC input.


The Four Models of the Series

There are four members of the CUS350MP series, each offering either 24, 30, 36, or 48 volts. The outputs are adjustable, as illustrated below.

Image courtesy of datasheet

Members of the CUS350MP series need no minimum load for proper operation. Although the units can’t be operated in parallel, it is possible to employ them in series if higher voltages are required.


Electrical Specifications

  • Power factor correction is as high as 0.98
  • Hold-up times are 20 or 15ms with convection or forced air cooling. respectively.
  • Switching Frequency is from 75 to 120 kHz. When the output load is light, series members will operate in intermediate burst mode.
  • Line regulation is 4%
  • Load regulation is 8%
  • External load capacitances are 10,000, 8,750, 7,500 and 5,000 µF for the 24, 30, 36 and 48 volt models, respectively.


Optional Features

These include:

  • A cover
  • Screw terminal connections
  • An AC fuse
  • Double-sided board coating


Physical Considerations

  • Series members operate over a range of -20 to +70°C. However, power output derates linearly at temperatures above 50°C, with 30% power available at +70°C.
  • The power supplies measure 88 x 183 x 44mm (including baseplate) and weigh 770g.



The units’ two means of protection (2 x MoPP) make them applicable for B and BF-rated medical equipment.

  • Input to output isolation is 4,000VAC with two means of protection.
  • Input to ground 1,500VAC (1 x MoPP) .
  • 1,500VAC (1 x MoPP) output to ground.


Regulatory, Safety, and Environmental Considerations

  • IEC/EN/ES 60601-1
  • IEC/UL/CSA/EN 62368-1
  • EN 62477-1 (OVC III)
  • CE Markings to the Low Voltage, EMC, and RoHS Directives.
  • EN 55011-B and EN 55032-B for conducted and radiated emissions.
  • EN 61000-3-2 for harmonics.
  • IEC60601-1-2 Edition 4 and IEC 61000-4 immunity standard.



These quiet units can deliver a peak power of 1,000 Watts, making them well-suited applications demanding low noise operation and capable of occasionally supplying high peak power. These can include:

  • Industrial printers 
  • Medical equipment utilizing DC motors