Skip to content

SMD code IV-

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.

20 parts are printed IV-

Not sure which one you have?

Answer up to 4 quick questions and these 20 parts are ranked, with a meter test that settles it. It works on a dead part too.

  • P4SMAFJ20ASMAFTVS diode, 2 pins, Blue RocketTVS diodeSMAF2 pinsBlue Rocket
    What it is
    TVS diode
    Maker
    Blue Rocket
    Package
    SMAF
    Pins
    2
    Details
    TVS diode, unidirectional
    Source
    Manufacturer datasheet

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

  • PTVSHC1RF20VBSOD-123FTVS diode, 2 pins, PrisemiTVS diodeSOD-123F2 pinsPrisemi
    What it is
    TVS diode
    Maker
    Prisemi
    Package
    SOD-123F
    Pins
    2
    Details
    TVS diode, 20 V working, bidirectional
    Source
    Manufacturer datasheet

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

  • SDFL20A-CSOD-123FTVS diode, 2 pins, SeCoSTVS diodeSOD-123F2 pinsSeCoS
    What it is
    TVS diode
    Maker
    SeCoS
    Package
    SOD-123F
    Pins
    2
    Source
    Manufacturer datasheet

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

  • SMAJ20ASMATVS diode, 2 pins, JieJieTVS diodeSMA2 pinsJieJie
    What it is
    TVS diode
    Maker
    JieJie
    Package
    SMA
    Pins
    2
    Source
    Manufacturer datasheet

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

  • SMAJ20A-AUSMATVS diode, 2 pins, JieJieTVS diodeSMA2 pinsJieJie
    What it is
    TVS diode
    Maker
    JieJie
    Package
    SMA
    Pins
    2
    Source
    Manufacturer datasheet

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

  • SMF20ASOD-123FTVS diode, 2 pins, Taitron ComponentsTVS diodeSOD-123F2 pinsTaitron Components
    What it is
    TVS diode
    Maker
    Taitron Components
    Package
    SOD-123F
    Pins
    2
    Source
    Manufacturer datasheet

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

  • TLV803EA18DPWX2SONVoltage supervisor, 5 pins, Texas InstrumentsVoltage supervisorX2SON5 pinsTexas Instruments
    What it is
    Voltage supervisor
    Maker
    Texas Instruments
    Package
    X2SON
    Pins
    5
    Details
    Low Power 250-nA IQ and Small Size Supply Voltage Supervisors
    Source
    Manufacturer datasheet

    Is it dead? The meter test is below: Integrated circuit.

  • CD214A-T20ASMATVS diode, 2 pins, BournsTVS diodeSMA2 pinsBourns
    What it is
    TVS diode
    Maker
    Bourns
    Package
    SMA
    Pins
    2
    Details
    TVS: 20V, 12.3A, 400W(1ms)
    Source
    Published code list

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

  • MAX6315US26D3SOT-1434 pins, Analog DevicesNot recordedSOT-1434 pinsAnalog Devices
    What it is
    Not recorded
    Maker
    Analog Devices
    Package
    SOT-143
    Pins
    4
    Source
    Published code list

    Is it dead? The meter test is below: This part.

  • MAX6315US26D3-TSOT-1434 pins, Analog DevicesNot recordedSOT-1434 pinsAnalog Devices
    What it is
    Not recorded
    Maker
    Analog Devices
    Package
    SOT-143
    Pins
    4
    Details
    CMOS-IC: Voltage Detector 2.63V, MR, -Reset ODO, 140ms
    Source
    Published code list

    Is it dead? The meter test is below: Integrated circuit.

  • P2SMLJ20A-ASOD-123FTVS diode, 2 pins, YeashinTVS diodeSOD-123F2 pinsYeashin
    What it is
    TVS diode
    Maker
    Yeashin
    Package
    SOD-123F
    Pins
    2
    Details
    Transient voltage supressor: Vrwm=20.0V, Vbr=22.20..24.50V, Ipp=6.2A, 200W(1ms)
    Source
    Published code list

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

  • 4 more parts have no package on record
    • SM4F20A-ATTVS diode, WayonTVS diodeNot recordedNot recordedWayon
      What it is
      TVS diode
      Maker
      Wayon
      Package
      Not recorded
      Pins
      Not recorded
      Source
      Manufacturer datasheet

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

    • SMF20A-ATTVS diode, WayonTVS diodeNot recordedNot recordedWayon
      What it is
      TVS diode
      Maker
      Wayon
      Package
      Not recorded
      Pins
      Not recorded
      Source
      Manufacturer datasheet

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

    • TESDA13VU1052Q3ESD protection diode, Taiwan SemiconductorESD protection diodeNot recordedNot recordedTaiwan Semiconductor
      What it is
      ESD protection diode
      Maker
      Taiwan Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Source
      Manufacturer datasheet

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

    • LT4ME20ATVS diode, Lite-On SemiconductorTVS diodeNot recordedNot recordedLite-On Semiconductor
      What it is
      TVS diode
      Maker
      Lite-On Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Transient voltage supressor: Vrwm=20V, Vbr=22.2..24.5V, Ipp=12.3A, 400W(1ms)
      Source
      Published code list

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

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.

Integrated circuit

Voltage with the board powered; ohms from each pin to ground with it off.

Working, it reads

Supply pin at its voltage and the output doing what the datasheet says. Readings between pins depend on the part.

Dead, it reads

  • A pin near 0 Ω to ground or to the supply pin where an identical part does not read that: failed short.
  • Supply present, output stuck: failed, or its load has.
On the board:
A pin shorted to ground on the board can be anything on that net. Lift the pin to be sure.
Compare:
The surest reference is the same IC on a working board, measured pin by pin.
Watch for:
Its protection diodes can read like junctions between pins, even like a transistor. That proves nothing either way.

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

This part

Diode range and ohms range, part lifted.

Working, it reads

Depends on what it is. The datasheet, or an identical part, says.

Dead, it reads

  • Between two pins, the same reading both ways, near 0 V with a continuous beep: shorted.
  • Open between every pair of pins: failed open, or a part that reads open when working.
On the board
this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
Compare:
If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.

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 IV-

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

Codes not listed here are printed on 3 more parts.

Did you find your part?

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