Sata-to-mSata-adapter Review

Summary

The adapter I purchased outputs quiet little current (power), so a lot of drives (especially large (power hungry drives)) can not be used with it.

Especially the drive I intended to use with it doesn't work.

I think the seller should have to have a warning label "Warning, can only supply 0.8 A (2.64 W)".

Intro

The mSata interface uses 3.3 V vs the sata interface which typically uses 5 V. (search internet for "msata voltage")

Looking at the adapter there is only one active component, which has the text:

ST L1117 33 ...

Searching the internet: one finds: https://www.st.com/resource/en/datasheet/ld1117.pdf

It is a 3.3 V LDO (Low dropout voltage converter). It drops the voltage to 3.3 V

How much power can the adapter (LDO) provide

Output current according to the LDO datasheet

Reading from the datasheet (page 12) it typically outputs 0.95 A (Although it is specified as a range (min 0.8 A to max 1.3 A) (so if you are unlucky you only get 0.8 A)

Output current, as tested with resistors

Using ohms law

V=I*R

(Voltage=Current*Resistance)

R=4.7 Ω => V=3.30 V, I=V/R=0.70 A
R=3.29 Ω => V=3.197 V, I=V/R=0.97 A
R=2.35 Ω => V=2.5 V, I=V/R=1.06 A

The mSata interface requires 3.30 (+-5%) V (search internet for "msata voltage").

So when below 0.95*3.3 = 3.135 [V] you are outside the specs.

So looking at the measured voltages above:

at 0.97 A (V=3.197 V) (inside the specs)

at 1.06 A (V=2.5 V) (outside the specs)

With Linear interpolation I estimate the adapter can provide 0.98 A (@3.135 V). (Linear interpolation calculator)

Calculating the output power using Electric power formula:

P=V*I

(Power=Voltage*Current)

So putting in the numbers (for the typical circuit from the datasheet), one gets:

Ptyp=3.3*0.95 = 3.135 [W]

How much power does typical mSata-drives need?

By searching the internet for: "msata drive power consumption" I found this page

Note, that the power consumed when idle is much lower, what one should look at is the power required when writing.

Note, also that the larger drives (more GB) seem to be more power hungry.

Of the 22 drives listed, more than half need more power than the 3.135 W the adapter typically can provide.