Ultra-compact GaN ATX power supply delivers up to 250 Watts

For me, an ATX power supply is one of those big boxes delivering 500W+ inside a PC tower, but since it’s not possible to build hardware with much lower power consumption, HDPLEX has designed an ultra-compact 250W passive ATX power supply using the same GaN (Gallium Nitride) found in some tiny USB-C power supplies.

With a footprint of 170 x 50 x 25mm, the company claims it’s the world’s smallest ATX power supply, and is particularly well-suited to SFF PC cases, but it should also perform quite well. well in other space-constrained applications with a board equipped with an ATX connector, or via an adapter board, or even some RGB LED projects.

GaN ATX power supply specifications:

  • Power – 250W (94% efficiency).
  • Input voltage – 90V-264V 50/60hz
  • DC output
    • +3.3V up to 10A
    • +5V up to 10A
    • +12V up to 20A
    • -12V up to 1A
    • +5VSb up to 3A
    • Max combined power for +3.3V and +5V – 80 W
    • Total power – 250W
  • Idle Power –
  • Noise level – zero dB operation with fully passive/fanless design,
  • PFC+LLC structure, energy efficiency level 5
  • 2x auto-grade GaN FETs on the PFC stage and 2x on the LLC stage
  • Power density of 1.18 W/cm³
  • Three-stage AC input filter to eliminate mains noise
  • 4x ATX 1KV 8A TTR8MF Full wave rectification
  • 150 µF Rubycon filter CAP and 9000 µF solid cap
  • Protections – UVP, OVP, SCP, OPP, OTP (See the Coolmaster article for an explanation of these terms)
  • Detachable IEC C14 connector to support other AC inputs for custom projects
  • Dimensions – 170 x 50 x 25mm, (aluminum housing to help dissipate heat)
  • Temperature range – -10°C – 75°C

500W GaN ATX power supply

If 250W is a little tight on the power budget, it is possible to connect (aka sync) two units for a combined 500W power output. The PSU comes with several cables:

  • 20cm IEC C14 AC cable – two ELR connectors
  • 25cm 24 pin (20+4) ATX power cable
  • 45cm CPU EPS 8 Pin (4+4) Cable
  • PCIe 45cm with red connector with dual 8 pin (6+2) cable
  • 45cm SATA power cable with 4 SATA power connectors
  • 45cm sync cable (45cm)

cables for 250W GaN ATX power supply

The HDPLEX 250W GaN All-in-One ATX Power Supply will be available in June for $145 with free shipping worldwide from warehouses in the US and Germany.


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Alan A. Seibert