2.5" parallel hard disk input voltage? \ VOGONS

2.5" parallel hard disk input voltage?

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First post, by Kahenraz

Posted on 2020-01-11, 17:13

Kahenraz Offline

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I ordered two msata to 2.5” pata adaptors off of eBay. Both use the same logic chip (JM20330) but one has a switch for selecting the input voltage of 5V or 3.3V.

As it is labeled as input, is this the voltage coming from the motherboard or is it instead a way to limit the voltage required by the msata device?

I'm also concerned that both use the same chip but only one offers voltage selection. What then is the input voltage of the second adaptor? I may need to pull out my multimeter for this...

Reply 1 of 2, by jtchip

Posted on 2020-01-13, 01:31

jtchip Offline

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According to the pinouts, 44-pin IDE only has 5V outputs (from the motherboard) while mSATA only has 3.3V input (to the SSD). The latter is different from regular SATA (3.5" or 2.5") which runs off 5V, and originally had 3.3V but was used so rarely that in SATA 3.2 it was redefined as DevSleep (usually implemented in laptops). The mSATA connector already has a separate DevSleep pin defined.
Given that mSATA only runs on 3.3V, my guess would be to set it to 3.3V but I'm not sure as "input" is a little vague (input to what?).

Reply 2 of 2, by jmarsh

Posted on 2020-01-13, 01:43

jmarsh Offline

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It's not an input setting, but will be for controlling the voltage on the IDE side. 3.3V can be used (most of the time) when a compact flash card is connected. A lot of PATA<->CF adapters only support higher PIO and DMA modes when 3.3V is selected but no idea if it would affect this adapter.

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