Skip to content
WhatSMDSign in

SMD code 12D in SMA

Marking codes are not standardised, and the same code is reused by unrelated makers for unrelated parts. Below is every part in our tables printed with it, and any printed with a code that is easy to misread as it, from the manufacturers' own marking tables and published code lists.

1 part in SMA is printed 12D

Not sure which one you have?

Answer up to 4 quick questions and these 3 parts are ranked, with a meter test that settles it. It works on a dead part too.

  • P4SMAJ12CASMAYeashinNot recordedYeashin
    What it is
    Not recorded
    Maker
    Yeashin
    Package
    SMA
    Pins
    2
    Details
    TVS: 12V, 20.1A, 400W(1ms), Bidirectional
    Source
    Published code list

    Is it dead? The meter test is below: TVS or ESD protection diode.

  • 2 more parts have no package on record. Nothing rules them out, so they stay.

Is it dead? One meter test per kind

Parts of the same kind are tested the same way, so each test is here once. Each part above points to its own.

TVS or ESD protection diode

Diode range, from the protected line to ground, part lifted if you can.

Working, it reads

A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

Dead, it reads

  • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
  • A reading both ways on a one-way part: leaky.
  • A one-way part open both ways: failed open.
On the board
, a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
Compare:
The same part on the next line or connector pin is the healthy reading to compare with.
Watch for:
A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

Printed with a code easy to misread as 12D

One character differs, and it is one that is easy to confuse under a lamp. Each code has a page of its own.

Codes that begin with 12D

For a marking with its end worn or burnt off. Each code has a page of its own.

Codes not listed here are printed on 44 more parts.

Did you find your part?

Open this in the search to correct a character or try another package.