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enter image description here

The dimensions are 1.60mm x 3.20mm.

Schematically, the side without the white stripe is connected to this node in a buck/boost converter... enter image description here

Here is the part in context, with the transistors Q1-Q4 labeled in sharpie... enter image description here

I am unable to trace where the other side is connected except for the shown decoupling caps that go to ground.

While it seems like it could be that resistor shown to the left in the schematic, the right side does not seem to be connected to ACP. There also seems to be a 3rd contact on the bottom right corner of the package...

enter image description here

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    \$\begingroup\$ My guess is a 4-terminal sense resistor. Maybe one of the sense terminals is not visible because it's soldered under the package. \$\endgroup\$
    – John D
    Commented Jul 7 at 17:53
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    \$\begingroup\$ Could you show a wider view, perhaps there are designators around, other context clues? \$\endgroup\$
    – Tim Williams
    Commented Jul 7 at 17:54
  • \$\begingroup\$ Is this from a TI reference design for the BQ25703A, or from something else? Is a bill of materials available? \$\endgroup\$
    – Chester Gillon
    Commented Jul 7 at 17:55
  • \$\begingroup\$ @TimWilliams Context photo added. thx. \$\endgroup\$
    – bigjosh
    Commented Jul 7 at 17:59
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    \$\begingroup\$ @JohnD There was in fact an extra pin hiding under under the bottom left corner, and this is indeed the exact 4-pin resistor part chesterGillon posted in his answer below based on your suggestion. Thank you! \$\endgroup\$
    – bigjosh
    Commented Jul 7 at 18:16

1 Answer 1

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Based upon the comment from @John D, and the dimensions, it could be a Littelfuse L4CA0612 Four-Terminal Surface Mount Resistor

The datasheet has the following picture:

L4CA0612 Four-Terminal Surface Mount Resistor

L4CA0612 dimensions

The dimensions are:

  • Width: 3.20±0.20
  • Length: 1.55±0.20
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  • \$\begingroup\$ Interesting part! What purpose would a part like this be used for? I see the datasheet says it has separate voltage sensing terminals, though I'm curious why separate terminals are needed for that \$\endgroup\$
    – Jordan Melo
    Commented Jul 11 at 15:04
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    \$\begingroup\$ @JordanMelo The datasheet mentions Kelvin sensing, also known as Four-terminal sensing. As it says on that linked Wikipedia page It is common to provide 4-wire connections to current-sensing shunt resistors of low resistance operating at high current \$\endgroup\$
    – Chester Gillon
    Commented Jul 11 at 22:46

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