What is this IC U503? (QFN16)

[cheon7886]

This is the image of the part of the NVLink Bridge PCB.
I recognized that U504 is STM32L031, but have no idea about U503. What is the part number of the IC?

[Labrat101]

Does this help
Its hard to see from your photo how many pins ..??

[gamalot]

STM32L031G6U6

https://www.st.com/en/microcontrollers-microprocessors/stm32l031g6.html

[thm_w]

Does this help
Its hard to see from your photo how many pins ..??

Close but "2003 15B2V" not 8.
16 pin QFN.
25MHz xtal on pins 6 and 7.

MSP430 has a 2003 marking 16-VQFN, but the crystal pins don't match up: https://www.ti.com/packaging/docs/partlookup.tsp?parent=pf&partNumber=MSP430F2003TRSAT#divline so its not that.

[Labrat101]

Does this help
Its hard to see from your photo how many pins ..??

Close but 15B2V not 8.
16 pin QFN.
25MHz xtal on pins 6 and 7.

MSP430 has a 2003 marking 16-VQFN, but the crystal pins don't match up: https://www.ti.com/packaging/docs/partlookup.tsp?parent=pf&partNumber=MSP430F2003TRSAT#divline so its not that.

Your right. Sorry  it did look like an '8' ..  A better photo would have been good as well ..
15B2V would make more sense ..   

 

[T3sl4co1l]

The pairs of chips (resistors?) nearby look suspiciously like a diff pair bias/decoupling network.  Perhaps it's a PCIe interface, perhaps to serial for the humble STM to talk with?

25MHz is suggestive of Ethernet, but I highly doubt that little chip is a PHY, or that Ethernet would find its way here in the first place.  May just be a coincidence.

Wonder what they need anything on there for, but at the same time I kind of wonder how it's not exponentially more (e.g. very wide, high bandwidth bus bridges?).  Presumably they've done their homework so it's not the latter, at least.  Nothing on the other side, just connectors..?

Tim

[newbrain]

I think it could be this one: Microchip SM802

Thanks to T3sl4co1l for putting me on the right path (crystal and differential output).
We all focused on the bold marking, but the chip number is below: 802356.