I would like to use an isolated DC/DC converter SIP to generate 19 V from a 12 V input voltage for a gate drive application with approximately 1.2 W output power required. The isolation voltage should be 5.2 kV.

Looking at the Murata's DCDC catalog there seems to be no obvious solution. Choosing a slightly higher output voltage and using an additional linear regulator would be an option. For example, the MEJ2D1212SC could be used to generate +-12 V to generate 24 V essentially. However, this will cause quite some additional (possibly unnecessary) power dissipation in the linear regulator.

The actual question is regarding the MGJ2D121505SC with output voltages of +15 V and -5 V. Using this as a 20 V supply would be favorable. However, the specified output currents are relatively low compared to the 2 W power specification as can be seen here:

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Is the power rating just a general approximation and the output currents are the meaningful data? When using this as a 20 V source, would I be limited to the 40 mA of "Output Current 2"?

  • 2
    \$\begingroup\$ Assuming you can stack them in the way you want, since the same current would flow through both outputs you'd take the lower current rating. Below that I see they have a 20V 80mA module which amounts to 1.6W. \$\endgroup\$
    – K H
    Jan 27, 2021 at 8:23
  • \$\begingroup\$ @KH Good point. I suspect not using one of the outputs will be unproblematic. \$\endgroup\$ Jan 27, 2021 at 8:38
  • \$\begingroup\$ What gate do you need 19 volts to drive? Best drive voltage is usually less than absolute maximum. On the datasheet there should be a graph to see if you really need 19v or if 15 or 20 are ok. \$\endgroup\$
    – K H
    Jan 27, 2021 at 8:43
  • \$\begingroup\$ 5.2kV is very a very high isolation voltage. Is it 5.2kV DC or 1sec pulse? Or AC? Your requirement suggests a custom power supply with some serious transformer- which is pain in a neck. If you can somehow relax the isolation requirement and live with Muata or Recom or Traco (or something else) that would be much easier. Maybe you could use two supplies in series \$\endgroup\$
    – user76844
    Jan 27, 2021 at 8:48
  • 1
    \$\begingroup\$ @LarsHankeln one thing i saw very common in servo drives- a flyback supply (mains to DC) that has a transformer with a dozen of secondary outputs. all isolated and all rated to high voltage. Just keep in mind, such solutions are possible, though it's not easy to make a transformer. Wurth (medcom) can probably help. Overall it's a bit more complex, but cheaper solution. \$\endgroup\$
    – user76844
    Jan 27, 2021 at 9:58


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