2
\$\begingroup\$

PCB photo

As the title really, can you identify this component?

It's on a line connecting a USB-C switch IC (PI3USB30532) to the USB-C connector and I believe the line is for Display port functionality.

How Critical are the values of this part as i have no way of finding them?

\$\endgroup\$
  • \$\begingroup\$ Sorry, it does help if you put the picture in before posting \$\endgroup\$ – Pintglass Feb 7 at 22:33
  • 1
    \$\begingroup\$ No worries. Are there any markings on them you can discern? \$\endgroup\$ – Tom Carpenter Feb 7 at 22:34
  • \$\begingroup\$ They look like dual resistor networks - perhaps termination resistors. You could try measuring them with a multi-meter, see if you get approx. 50Ohm or 100Ohm across them. \$\endgroup\$ – Tom Carpenter Feb 7 at 22:36
  • \$\begingroup\$ No there are no markings on them. \$\endgroup\$ – Pintglass Feb 7 at 22:38
  • 4
    \$\begingroup\$ Most likely in-line ESD protection devices as they have pads for ground connection. They could also be common mode chokes. \$\endgroup\$ – Justme Feb 7 at 22:40
4
\$\begingroup\$

This is an EMI choke. Take a closer look or check with a magnet - the body of this component is made of ferrite.

\$\endgroup\$
  • \$\begingroup\$ Agreed. Looks like a package with ESD protection built in. Something like these \$\endgroup\$ – Brandon Hill Feb 7 at 23:18
3
\$\begingroup\$

This component is called "Common-mode Choke". Example: Murata DLP11TB800UL2L. The choke is placed into differential data line like this:

enter image description here

This CMC is meant to suppress common-mode ESD events and reduce unwanted emission (which may happen when the transmission line is not perfectly balanced).

See also TDK offerings and typical use of individual chokes.

enter image description here

These components don't incude TVS elements, these packages have more than 4 pins.

\$\endgroup\$
  • \$\begingroup\$ Actually, the last picture from TDK is silly, USB2.0 don't have DC-decoupling caps. Funny, a typical marketoidal glitch. \$\endgroup\$ – Ale..chenski Feb 8 at 5:02

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.