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SMD code N in DFN

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.

Not sure which one you have?

Answer up to 4 quick questions and these 37 parts are ranked, with a meter test that settles it. It works on a dead part too.

15 parts have no package on record. Nothing rules them out, so they stay.

  • KDZ110VZener diode, KECZener diodeNot recordedKEC
    What it is
    Zener diode
    Maker
    KEC
    Package
    Not recorded
    Pins
    Not recorded
    Source
    Manufacturer datasheet

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

  • LDLN025J32RLDO regulator, STMicroelectronicsLDO regulatorNot recordedSTMicroelectronics
    What it is
    LDO regulator
    Maker
    STMicroelectronics
    Package
    Not recorded
    Pins
    Not recorded
    Source
    Manufacturer datasheet

    Is it dead? The meter test is below: Voltage regulator.

  • PHS518CESD protection diode, ProTek DevicesESD protection diodeNot recordedProTek Devices
    What it is
    ESD protection diode
    Maker
    ProTek Devices
    Package
    Not recorded
    Pins
    Not recorded
    Details
    High Powered Surge Protection TVS Array
    Source
    Manufacturer datasheet

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

  • PMEG4002AESFSchottky diode, 2 pins, NexperiaSchottky diode2 pinsNexperia
    What it is
    Schottky diode
    Maker
    Nexperia
    Package
    Not recorded
    Pins
    2
    Details
    40 V, 0.2 A low VF MEGA Schottky barrier rectifier
    Source
    Manufacturer datasheet

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

  • SCS222DSTL-CSwitching diode, SeCoSSwitching diodeNot recordedSeCoS
    What it is
    Switching diode
    Maker
    SeCoS
    Package
    Not recorded
    Pins
    Not recorded
    Source
    Manufacturer datasheet

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

  • TCR3UG15ALDO regulator, ToshibaLDO regulatorNot recordedToshiba
    What it is
    LDO regulator
    Maker
    Toshiba
    Package
    Not recorded
    Pins
    Not recorded
    Details
    TCR3UG series
    Source
    Manufacturer datasheet

    Is it dead? The meter test is below: Voltage regulator.

  • TCR4DG185LDO regulator, ToshibaLDO regulatorNot recordedToshiba
    What it is
    LDO regulator
    Maker
    Toshiba
    Package
    Not recorded
    Pins
    Not recorded
    Details
    TCR4DG series
    Source
    Manufacturer datasheet

    Is it dead? The meter test is below: Voltage regulator.

  • TCR5RG18ALDO regulator, ToshibaLDO regulatorNot recordedToshiba
    What it is
    LDO regulator
    Maker
    Toshiba
    Package
    Not recorded
    Pins
    Not recorded
    Details
    TCR5RG series
    Source
    Manufacturer datasheet

    Is it dead? The meter test is below: Voltage regulator.

  • TVSG25VCESGPESD protection diode, ChenmkoESD protection diodeNot recordedChenmko
    What it is
    ESD protection diode
    Maker
    Chenmko
    Package
    Not recorded
    Pins
    Not recorded
    Details
    STANDARD CAPACITANCE TVS, 5 V
    Source
    Manufacturer datasheet

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

  • VCUT03B1-DD1ESD protection diode, VishayESD protection diodeNot recordedVishay
    What it is
    ESD protection diode
    Maker
    Vishay
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Bidirectional Symmetrical (BiSy) Single Line ESD-Protection Diode in LLP1006-2M
    Source
    Manufacturer datasheet

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

  • VS3V3BB1FSESD protection diode, ROHMESD protection diodeNot recordedROHM
    What it is
    ESD protection diode
    Maker
    ROHM
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Transient Voltage Suppressor
    Source
    Manufacturer datasheet

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

  • 2SC6114NPN transistor, 3 pins, ROHMNPN transistor3 pinsROHM
    What it is
    NPN transistor
    Maker
    ROHM
    Package
    Not recorded
    Pins
    3
    Details
    gp npn 50V 100mA comp 2SA2199
    Source
    Published code list

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

  • BAR65-02W2 pins, InfineonNot recorded2 pinsInfineon
    What it is
    Not recorded
    Maker
    Infineon
    Package
    Not recorded
    Pins
    2
    Source
    Published code list

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

  • BU28UA3WNVXLDO regulator, ROHMLDO regulatorNot recordedROHM
    What it is
    LDO regulator
    Maker
    ROHM
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Linear voltage regulator IC: LDO, 2.8V±1%, 300mA, +CE
    Source
    Published code list

    Is it dead? The meter test is below: Voltage regulator.

  • CDZ12BZener diode, ROHMZener diodeNot recordedROHM
    What it is
    Zener diode
    Maker
    ROHM
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Z-diode: 12V±2,5%, 20mA, 1W
    Source
    Published code list

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

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.

Voltage regulator

Voltage, board powered, black probe on ground. Then ohms with the power off.

Working, it reads

Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.

Dead, it reads

  • Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
  • Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
  • Power off, input to output near 0 Ω: shorted.
On the board:
An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
Compare:
The same regulator on another rail or another board shows the right voltages and the right resistances.
Watch for:
Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.

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

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.

Schottky diode

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

Working, it reads

About 0.15 to 0.45 V anode to cathode, roughly half a silicon diode, and open the other way.

Dead, it reads

  • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
  • A reading the wrong way round as well: leaky.
  • Open both ways: failed open.
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 large Schottky can read about 0.1 V forward and beep like a short, and leaks a little the wrong way when good, more when warm. It is shorted only if it reads the same both ways. Measure it cold, beside an identical cold one.

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

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.

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.

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.

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