I'm looking for a 4-poles (TRRS) 3.5mm jack socket with integrated switch, and stumbled upon this connector schematic:

FC68129 schematic

(this is an extract from the CLIFF FC68129 datasheet)

I understand that pins 1, 2, 3 and 4 are respectively the sleeve, rings and tip contacts, and pin 6 the tip normally-closed switch.

What about pin 5 and its associated switch on pin 7? The other pins already yield the right amount of connections for a TRRS jack socket.

My guess is that it could be some kind of "fully inserted plug" switch, but I cannot find the topmost "weird lengthy closed triangle" symbol in other datasheets.

This seller has a 360° photo view of the connector, but it does not help me.


1 Answer 1


I would say that terminal 1 is the sleeve, 2 is first ring, 3 is second ring and 4 is tip.

6 is a switch contact normally connected to 4/tip contact when there is no plug inserted.

5 and 7 form an isolated switch, closed with no plug inserted, and not connected to any of the other terminals at any time.

  • \$\begingroup\$ That's my thoughts as well. Given the placement of the two switches arrow 5/7 would open before the tip switch. Do you have any source for that ? \$\endgroup\$
    – strnk
    Mar 22, 2019 at 10:17
  • \$\begingroup\$ @strnk: I wouldn't count on any particular order of operation of the switches - you're supposed to push the plug all the way in... \$\endgroup\$ Mar 22, 2019 at 15:35

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