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Given this MP2331H, datasheet says it can provide

2A of continuous output current with excellent load and line regulation over a wide input range

Now let's say I'm in a situation where normally 2A is more than enough for my needs, but sometimes my needs can be as large as 3.5A which is well above this tiny SMPS's limits.

My idea is to connect two of these devices parallel, i.e. connect their outputs and GNDs.

But this feels lame, I might also need some diodes which will introduce unnecessary heating issues.

Anyway I could just chose another one which can provide higher current, I know. But can I join two of these ICs together to reach my goal?

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  • \$\begingroup\$ "Sometimes" as in microseconds or days? \$\endgroup\$
    – Andy aka
    Jun 24 at 12:50
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    \$\begingroup\$ my needs can be as large as 3.5A Then just get a 3.5 A regulator chip/module. Or better, add some margin and get a 4 A or even a 5 A model. No you should never put DCDC converters in parallel unless they are specifically designed for that (good luck finding one). \$\endgroup\$ Jun 24 at 13:06
  • \$\begingroup\$ @Andyaka: sometimes means peak, in seconds or even minutes. \$\endgroup\$
    – Daniel
    Jun 25 at 12:11
  • \$\begingroup\$ You can get SMPS designed for parallel connection. I've just seen one designed in to commercial mass-production equipment, well two in parallel. But they are very much the rare exception, not the normal case. \$\endgroup\$
    – TonyM
    Jul 9 at 21:36
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The Switched Output of this device is a Totem Pole output, with a High Side FET driving high, and a Low Side FET pulling low. There is no synchronization provided on this part, so the two devices will cycle independently. When the High Side of one output is on, and the Low Side of the other is on, and they are connected together --- they will short circuit the 5-24V input power.

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My idea is to connect two of these devices parallel, i.e. connect their outputs and GNDs

In an ideal and perfect world this would work unfortunately, one of the devices will want to regulate the output voltage at a slightly different level to the other device and they'll fight real mean because they are synchronous buck converters. One may even destroy the other but, there is a possibility that one will supply all the output current whilst the other one sits and sulks and contributes no output current.

Synchronous bucks are particularly nasty (because they have a push-pull output) and can fight. Worst case scenario is that they both annihilate each other.

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