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SMD code D3

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.

18 parts are printed D3

Not sure which one you have?

Answer up to 4 quick questions and these 18 parts are ranked, with a meter test that settles it. It works on a dead part too.

  • 1N914BWSOD-123FSwitching diode, 2 pins, Taiwan Semiconductor
    What it is
    Switching diode
    Maker
    Taiwan Semiconductor
    Package
    SOD-123F
    Pins
    2
    Source
    From the manufacturer's datasheet

    Is it dead? The meter test is below: Silicon diode.

    Datasheetfor 1N914BW, opens in a new tab
  • AO6403SOT-23-6P-channel MOSFET, 6 pins, Alpha & Omega Semiconductor
    What it is
    P-channel MOSFET
    Maker
    Alpha & Omega Semiconductor
    Package
    SOT-23-6
    Pins
    6
    Details
    P-channel MOSFET (8-60 V)
    Source
    From the manufacturer's datasheet

    Is it dead? The meter test is below: P-channel MOSFET.

    Datasheetfor AO6403, opens in a new tab
  • AO6403LSOT-23-6P-channel MOSFET, 6 pins, Alpha & Omega Semiconductor
    What it is
    P-channel MOSFET
    Maker
    Alpha & Omega Semiconductor
    Package
    SOT-23-6
    Pins
    6
    Details
    P-channel MOSFET (8-60 V)
    Source
    From the manufacturer's datasheet

    Is it dead? The meter test is below: P-channel MOSFET.

    Datasheetfor AO6403L, opens in a new tab
  • BCW33SOT-23NPN transistor, 3 pins, Nexperia
    What it is
    NPN transistor
    Maker
    Nexperia
    Package
    SOT-23
    Pins
    3
    Source
    From the manufacturer's datasheet

    Is it dead? The meter test is below: NPN transistor.

    Datasheetfor BCW33, opens in a new tab
  • BZD27C4V7PSOD-123FZener diode, 2 pins, Vishay
    What it is
    Zener diode
    Maker
    Vishay
    Package
    SOD-123F
    Pins
    2
    Details
    4.7 V Zener diode
    Source
    From the manufacturer's datasheet

    Is it dead? The meter test is below: Zener diode.

    Datasheetfor BZD27C4V7P, opens in a new tab
  • BZT52-C56SOD-123Zener diode, 2 pins, Nexperia
    What it is
    Zener diode
    Maker
    Nexperia
    Package
    SOD-123
    Pins
    2
    Source
    From the manufacturer's datasheet

    Is it dead? The meter test is below: Zener diode.

    Datasheetfor BZT52-C56, opens in a new tab
  • EMD3SOT-563Digital transistor (resistors built in), 6 pins, JSCJ
    What it is
    Digital transistor (resistors built in)
    Maker
    JSCJ
    Package
    SOT-563
    Pins
    6
    Details
    Digital transistor (bias resistors built in), NPN PNP
    Source
    From the manufacturer's datasheet

    Is it dead? The meter test is below: Digital transistor.

    Datasheetfor EMD3, opens in a new tab
  • MMBZ5228BSOT-23Zener diode, 3 pins, Panjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOT-23
    Pins
    3
    Source
    From the manufacturer's datasheet

    Is it dead? The meter test is below: Zener diode.

    Datasheetfor MMBZ5228B, opens in a new tab
  • MMBZ5228BTWSOT-363Zener diode, 6 pins, Panjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOT-363
    Pins
    6
    Source
    From the manufacturer's datasheet

    Is it dead? The meter test is below: Zener diode.

    Datasheetfor MMBZ5228BTW, opens in a new tab
  • MMBZ5228BWSOT-323Zener diode, 3 pins, Panjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOT-323
    Pins
    3
    Source
    From the manufacturer's datasheet

    Is it dead? The meter test is below: Zener diode.

    Datasheetfor MMBZ5228BW, opens in a new tab
  • MMSZ5228BSOD-123Zener diode, 2 pins, Panjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOD-123
    Pins
    2
    Details
    SMD Planar Zener Diodes
    Source
    From the manufacturer's datasheet

    Is it dead? The meter test is below: Zener diode.

    Datasheetfor MMSZ5228B, opens in a new tab
  • MMSZ5228B-AUSOD-123Zener diode, 2 pins, Panjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOD-123
    Pins
    2
    Source
    From the manufacturer's datasheet

    Is it dead? The meter test is below: Zener diode.

    Datasheetfor MMSZ5228B-AU, opens in a new tab
  • MMSZ5228BSSOD-323Zener diode, 2 pins, Panjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOD-323
    Pins
    2
    Source
    From the manufacturer's datasheet

    Is it dead? The meter test is below: Zener diode.

    Datasheetfor MMSZ5228BS, opens in a new tab
  • MMSZ5228BS-AUSOD-323Zener diode, 2 pins, Panjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOD-323
    Pins
    2
    Source
    From the manufacturer's datasheet

    Is it dead? The meter test is below: Zener diode.

    Datasheetfor MMSZ5228BS-AU, opens in a new tab
  • PUMD3SOT-363Digital transistor (PNP, resistors built in), 6 pins, Nexperia
    What it is
    Digital transistor (PNP, resistors built in)
    Maker
    Nexperia
    Package
    SOT-363
    Pins
    6
    Details
    50 V, 100 mA NPN/PNP resistor-equipped double transistor; R1 = 10 kΩ, R2 = 10 kΩ
    Source
    From the manufacturer's datasheet

    Is it dead? The meter test is below: Digital transistor.

    Datasheetfor PUMD3, opens in a new tab
  • UMD3NSOT-363Digital transistor (resistors built in), 6 pins, JSCJ
    What it is
    Digital transistor (resistors built in)
    Maker
    JSCJ
    Package
    SOT-363
    Pins
    6
    Details
    Digital transistor (bias resistors built in), PNP NPN
    Source
    From the manufacturer's datasheet

    Is it dead? The meter test is below: Digital transistor.

    Datasheetfor UMD3N, opens in a new tab
  • 2 more parts have no package on record
    • ESH1DMRectifier, Taiwan Semiconductor
      What it is
      Rectifier
      Maker
      Taiwan Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Source
      From the manufacturer's datasheet

      Is it dead? The meter test is below: Silicon diode.

      Datasheetfor ESH1DM, opens in a new tab
    • ESH1DMHRectifier, Taiwan Semiconductor
      What it is
      Rectifier
      Maker
      Taiwan Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Source
      From the manufacturer's datasheet

      Is it dead? The meter test is below: Silicon diode.

      Datasheetfor ESH1DMH, opens in a new tab

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.

Silicon diode

Diode range, part lifted or one leg off the pad. Red probe on the anode.

Working, it reads

About 0.5 to 0.8 V anode to cathode, and open the other way. Small switching diodes read about 0.6 to 0.7 V; large rectifiers can read a little lower.

Dead, it reads

  • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
  • Open both ways: failed open.
  • A reading the wrong way round as well: leaky.
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.
Watch for:
A three-pin body can hold two diodes. With a common pin they read two junctions from that pin, just like a transistor; in series they read two drops end to end. Test each pair the datasheet names.

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

P-channel MOSFET

Diode range, part lifted. Test drain to source first, then short gate to source and test again.

Working, it reads

Red probe on the drain, black on the source: about 0.4 to 0.9 V, the body diode. Open the other way. The gate reads open to both other pins, both ways.

Dead, it reads

  • Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
  • The gate reads low to source or drain: gate shorted. Often all three pins end up shorted together.
  • No body diode at all: failed open.
On the board
the gate usually has a resistor to the source, so gate to source reads that resistor, which is not a fault. Lift a leg to be sure.
Compare:
If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
Watch for:
The diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.

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

NPN transistor

Diode range, part lifted or its base leg off the pad.

Working, it reads

Red probe on the base reads about 0.6 to 0.75 V to the emitter and to the collector, and open the other way round. Collector to emitter reads open both ways.

Dead, it reads

  • Collector to emitter the same both ways, near 0 V with a continuous beep: shorted. The commonest failure.
  • The base the same both ways to another pin, near 0 V or a middling value: a shorted junction.
  • Only one junction reads, or none: a junction has failed open. It then looks like a diode.
  • A reading the wrong way round, where it should be open: leaky.
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.
Watch for:
A pair of diodes with a common pin reads just like a transistor, and some transistors carry a built-in diode or resistor. The datasheet says which.

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

Zener diode

Diode range for the forward check, part lifted, red probe on the anode. A bench supply for the Zener voltage.

Working, it reads

About 0.6 to 0.8 V forward and open in reverse on the diode range. Its Zener voltage shows only on a supply: feed it through a resistor that sets about 5 mA, cathode to positive, read quickly, and it should hold near its rated voltage.

Dead, it reads

  • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
  • Open both ways, forward too: failed open.
  • Holds well off its rated voltage on the supply test: drifted.
  • A soft knee, or a voltage that creeps on the supply test: leaky.
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.
Watch for:
A meter's diode range stops at about 2 to 3 V, so almost every Zener reads open in reverse on it, good or bad; a 3 V meter may just show a 2.4 or 2.7 V part. Above about 3 V the meter cannot tell a Zener from a plain diode.

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

Digital transistor

Ohms range, part lifted. The datasheet gives the built-in resistors: R1 in series with the base, R2 from base to emitter.

Working, it reads

Base to emitter reads about R1 plus R2 either way round, about 20 kΩ on a 10 k and 10 k part, give or take their wide tolerance. Collector to emitter reads open. A part with no R2 reads a junction behind R1 one way instead.

Dead, it reads

  • Collector to emitter the same both ways, near 0 Ω with a continuous beep: shorted.
  • From the base, open or far above R1 plus R2: R1 has failed. Static damage shows here most often.
  • Base to emitter near 0 Ω: failed short.
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:
The readings depend on the resistor values, so an identical part elsewhere on the board is the surest reference. Measure it the same way.
Watch for:
On the diode range a good part with 10 kΩ resistors reads open on every pair, so a good part looks dead there. Use the ohms range.

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

Digital transistor

Ohms range, part lifted. The datasheet gives the built-in resistors: R1 in series with the base, R2 from base to emitter.

Working, it reads

Base to emitter reads about R1 plus R2 either way round, about 20 kΩ on a 10 k and 10 k part, give or take their wide tolerance. Collector to emitter reads open. A part with no R2 reads a junction behind R1 one way instead.

Dead, it reads

  • Collector to emitter the same both ways, near 0 Ω with a continuous beep: shorted.
  • From the base, open or far above R1 plus R2: R1 has failed. Static damage shows here most often.
  • Base to emitter near 0 Ω: failed short.
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:
The readings depend on the resistor values, so an identical part elsewhere on the board is the surest reference. Measure it the same way.
Watch for:
On the diode range a good part with 10 kΩ resistors reads open on every pair, so a good part looks dead there. Use the ohms range.

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 D3

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 D3

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

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