New Industry Products

XP Power Debuts Five Conduction-Cooled 75W AC-DC Power Supplies

April 21, 2021 by Gary Elinoff

The new units feature base plate cooling, an integral AC fuse, EMC filter and a hold-up capacitor to simplify design and save space

The ASB75 Series’ base plate cooling capability enables passive cold wall cooling to transfer heat to the outside of the equipment. The units also feature an optional heatsink, allowing for convection or forced air cooling if desired. 

The ASB75 Series. Image courtesy of XP Power
The ASB75 Series. Image courtesy of XP Power


All members of the new fanless series of power supplies operate from 90 to 264 VAC inputs and provide 75 watts of power with efficiencies of up to 90%. Single output voltages of either 12, 15, 24, 36 or 48 VDC are available. The units sport a power density of 20 watts per square inch and are offered in half brick sized (2.28 x 2.40 x 0.67 inch) packages.


Features Common to all Series Members

The output voltages of all five units are adjustable. Through the application of external resistors, the output voltage can be adjusted upwards or downwards by 10%.

These 75 watt units draw only 150 mW from the mains line during no load output conditions. Their switching frequency is 65 kHz, and the series members boast a MTBF of over 160 khrs as per MIL-HDBK-217F, +25°C GB

Derating, with the devices fitted to a heatsink with a thermal resistance of 2.91°C/W in natural convection, begins 50℃. The units’ power output also derates linearly down to 70 watts as the input voltage decreases from 100 to 90 VAC.

All members of the series are internally fused. Other protections include:

  • Overload protection
  • Overvoltage protection with auto recovery
  • Short circuit protection. Trip and restart (hiccup mode)
  • Thermal protection, auto restarting


The Individual Members of the Series

  Output voltage Output current Noise and Ripple Efficiency
ASB75US12  12.0 volts 6.25 amps 120 mV 88%
ASB75US15  15.0 volts 5.00 amps 150 mV 88%
ASB75US24  24.0 volts 3.12 amps 240 mV 89%
ASB75US36 36.0 volts 2.05 amps 360 mV 89%
ASB75US48  48.0 volts 1.56 amps 480 mV 90%



  • Industrial electronics
  • Information technology equipment (ITE)
  • IoT
  • Commercial off the shelf products (COTS)



All members of the ASB75 series are fully encapsulated, which provides for increased reliability in the harsh applications and environments that these tough power supplies are intended for. 

  • The half-brick sized units feature baseplate operating temperature ranges of -40 to +85℃
  • Unit weight is 0.26 lb
  • Shock as per IEC68-2-27
  • Vibration as per IEC68-2-6


EMC Emissions and Immunity

No external components are required to meet tough EMC emissions and immunity standards. See the datasheet for details.

For EMC Immunity phenomenon, the relevant subsections of EN61000-4 apply to:

  • ESD
  • Radiated
  • EFT/Burst
  • Surge
  • Conducted
  • Dips and Interruptions


For EMC Emissions: 

  • Emissions: EN55032 
  • Harmonic Current: EN61000-3-2 
  • Voltage Flocker: EN61000-3-3 


Regulatory and Safety

The power supplies feature earth leakage currents of 500µA and satisfy UL- TUV- and EN- 62368-1



  • Input to output 3000 VAC
  • Input to ground 1500 VAC
  • Output to ground 500 VDC