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I have the following DC-DC convertor:

  • MEJ2D0512SC enter image description here

The output of the this module is ±12V and I need to reduce it to ±7V, Would you please share you though what is the best approach?

Possible approach:

  • Positive Rail (+12V → +7V): Using a linear voltage regulator like LM317 (adjustable) or 7807 (fixed) to regulate down to +7V.

  • Negative Rail (-12V → -7V): Using a negative voltage regulator like LM337 (adjustable) or 7907 (fixed) for -7V.

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    \$\begingroup\$ Sounds reasonable but watch the power dissipation. \$\endgroup\$ Commented Apr 1 at 12:27
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    \$\begingroup\$ Best approach depends on what situation you are in. For what components you need to drop the voltage and why? Is it possible to change those components so you can just use +/- 12V? \$\endgroup\$ Commented Apr 1 at 12:28
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    \$\begingroup\$ What is the max. load current? \$\endgroup\$ Commented Apr 1 at 13:06
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    \$\begingroup\$ if you need to add two regulators at the output of your regulator, would it make sense to maybe build an isolated DC/DC converter that directly produces the voltage you need right away? (also, +-7 V is pretty surprisingly specific, are you sure the same circuitry wouldn't work with +- 6 V or +- 9 V?) \$\endgroup\$ Commented Apr 1 at 18:18
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    \$\begingroup\$ What range of output current is required? \$\endgroup\$ Commented Apr 2 at 1:28

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I wouldn't like the chances of a -7V fixed regulator being in stock when needed, adjustable might be a better bet. Might be okay for +7V, but I would also look at an adjustable one.

Best approach is heavily dependent on the current range. Also many cheap regulators may not be able to reliably handle the 12V input- it can go higher if lightly loaded and have some hash on it, so I wouldn't put anything less than a 16V regulator in there.

The recommended minimum current for best performance is 10% of maximum, so that's 8.3mA, so the Iq of the regulator doesn't matter much.

Pay attention to the maximum power dissipation as Andy says, you may find a tiny regulator overheating- you're putting potentially about as much heat into the regulators as the entire rest of the circuit. Calcuate the worst-case junction temperature at the maximum ambient temperature and keep it well below the maximum limit in the datasheet.

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