what kind of relay driver used on impedance analyzer board?

[Maxxim]

its small 8 leg Ic with mark 743  used as IC 4 and IC5
 

[JColvin]

Hi @Maxxim,

Those are A3910 Dual Half Bridge Motor Drivers from Allegro Microsystems as shown in the Impedance Analyzer Schematic available on its Resource Center: https://digilent.com/reference/add-ons/impedance-analyzer/start#documentation.

Let me know if you have any questions.

Thanks,
JColvin

[Maxxim]

in datasheet drives only in 8-Contact DFN.  This one is different also as marking on case.
thanks make me kinds confused  What is 743?

May be really assembly different from the initial design?

Edited January 20 by Maxxim

[JColvin]

Hi @Maxxim,

I received confirmation from the Engineering Services Manager that the part I mentioned, A3910EEETR-T, is indeed the part loaded on the board; no alternates or substitues are approved for this product.

The 743 marking on your module is almost certainly some sort of manufacturing lot code that Allegro Microsystems uses, though I don't have any additional insight as to what it might indicate. The markings of the Impedance Analyzer module on my desk are 143 followed by a 10 on the next line.

The only other thing I can think of that might be part of your query is the fact that the landing pad traces extend beyond the edge of the DFN package which is standard for this type of package.

Let me know if you have any questions.

Thanks,
JColvin