For a project i used some ACS712 and ACS758 current sensors. These are of the typical Chinese type found on Aliexpress and ebay. I'm doing a version 2 of this project with a actual custom PCB.
While shopping for these chips i found out that both chips are listed as "Not for New Design" since 2017, and the ACS723 and ACS770 are listed as replacements.
The old versions however are widely available on Aliexpress and are very cheap both in full breakout board or loose chips.
| **ACS712 ** | **ACS722 ** | **ACS758 ** | **ACS770 ** | |
|---|---|---|---|---|
| **Aliexpress (full board) ** | $ <$ 1,- | $ n/a | $ 5,- | $ 5,- |
| **Aliexpress (chip only) ** | $ <$ 1,- | $ n/a | $ 2,- | $ 1,50 |
| **LCSC (chip only) ** | $ 2,- | $ 5,50 | $ 5,- | $ 6,50 |
| **Farnell/digikey (cheapest) ** | $ 2,- | $ 3,50 | $ 5,- | $ 5,- |
I'm noticing a couple of things here.
-
Aliexpress is extremely cheap with all of these parts. Its hard to imagine they can build a full breakoutboard with a $ 2,- chip for less than $ 1,- Are these fake?
-
The ACS712 successor(ACS722) is not as easy available and is 2-3x more expensive
-
IT makes more sense to use the newer ACS770 instead of the older ACS758
I need several of these chips for my design. Currently this design is still intended just for me, but if i'm happy with the design and other people like it, i may want to sell it in small batches or make it open source. This means i want to keep the BOM costs down.
2x ACS770 + 3x ACS722 can cost me up to $ 30,- if i order trough LCSC or another renowned online shop.
2x ACS770 + 3x ACS712 can be bought on Aliexpress for only $ 6,-. That is a huge difference in costs.
So i'm wondering if anyone knows if the chips on Aliexpress are fake, and are of (much) worse quality.
Maybe some of you have experience with this.
I'm also wondering if i should go for the older ACS712, or ACS722. These do not use the same schematic and external pats.
Hope you guys can give some advice on this...
