Ratiomatic hall effect identification

I am trying to identify source for a magnetic field sensor which operates off 5V and has a ratiomatic signal output between 500mV and 4500mV depending on the proximity of a magnet.

The component has what looks like chips connected together with six open conductors and also the three conductors for the +5v VCC, ground, and signal connections.

The markings are as appears on the top section to be 17505 with what appears to be KMA 21C m2991 T01 on the bottom section.

Chip 3a


Unfortunately I could not find anything for the part markings on this one.

Hi rho,

It’s almost certainly an NXP sensor. These two look similar (KMA210:115, KMA215,118) though I can’t yet tell if it might be one of them or another related part. Assuming that the “C” might be a zero, it may well be the KMA210, but it looks like there are several variants. Also, unfortunately they are all obsolete.

Here’s page 31 of the datasheet for the KMA210.

Is it possible to get a better image of the markings?


Thanks to all. Greatly appreciated. I have found an alternate.