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SMD code X5s

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.

The last letter, s, is lower case, which on NXP and Philips parts is a date or factory code, so it was set aside and X5 was searched.

110 parts are printed X5s

Not sure which one you have?

Answer up to 4 quick questions and these 50 parts are ranked, with a meter test that settles it. It works on a dead part too.

  • BZX384C75SOD-323Zener diode, 2 pins, Taitron ComponentsZener diodeSOD-3232 pinsTaitron Components
    What it is
    Zener diode
    Maker
    Taitron Components
    Package
    SOD-323
    Pins
    2
    Source
    Manufacturer datasheet

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

  • BZX384C75-Q1SOD-323Zener diode, 2 pins, Formosa MicrosemiZener diodeSOD-3232 pinsFormosa Microsemi
    What it is
    Zener diode
    Maker
    Formosa Microsemi
    Package
    SOD-323
    Pins
    2
    Source
    Manufacturer datasheet

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

  • BZX584B39SOD-523Zener diode, 2 pins, Galaxy MicroelectronicsZener diodeSOD-5232 pinsGalaxy Microelectronics
    What it is
    Zener diode
    Maker
    Galaxy Microelectronics
    Package
    SOD-523
    Pins
    2
    Source
    Manufacturer datasheet

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

  • BZX584C75SOD-523Zener diode, 2 pins, PanjitZener diodeSOD-5232 pinsPanjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOD-523
    Pins
    2
    Details
    75V, 150mW, Surface Mount Zener Diodes
    Source
    Manufacturer datasheet

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

  • BZX584C75-AUSOD-523Zener diode, 2 pins, PanjitZener diodeSOD-5232 pinsPanjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOD-523
    Pins
    2
    Source
    Manufacturer datasheet

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

  • BZX784B6V8SOD-723Zener diode, 2 pins, SeCoSZener diodeSOD-7232 pinsSeCoS
    What it is
    Zener diode
    Maker
    SeCoS
    Package
    SOD-723
    Pins
    2
    Source
    Manufacturer datasheet

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

  • BZX784C6V8SOD-723Zener diode, 2 pins, SeCoSZener diodeSOD-7232 pinsSeCoS
    What it is
    Zener diode
    Maker
    SeCoS
    Package
    SOD-723
    Pins
    2
    Source
    Manufacturer datasheet

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

  • CZRV52C75S-P2-HFSOD-323Zener diode, 2 pins, ComchipZener diodeSOD-3232 pinsComchip
    What it is
    Zener diode
    Maker
    Comchip
    Package
    SOD-323
    Pins
    2
    Details
    75 V 0.2 mW zener diode
    Source
    Manufacturer datasheet

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

  • ET7H250YDFNLDO regulator, ETEKLDO regulatorDFNNot recordedETEK
    What it is
    LDO regulator
    Maker
    ETEK
    Package
    DFN
    Pins
    Not recorded
    Source
    Manufacturer datasheet

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

  • GZF75CSOD-123FZener diode, 2 pins, Galaxy MicroelectronicsZener diodeSOD-123F2 pinsGalaxy Microelectronics
    What it is
    Zener diode
    Maker
    Galaxy Microelectronics
    Package
    SOD-123F
    Pins
    2
    Details
    75V, 5%, Surface Mount Zener Diodes
    Source
    Manufacturer datasheet

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

  • MM1Z33BWSOD-123Zener diode, 2 pins, YFWZener diodeSOD-1232 pinsYFW
    What it is
    Zener diode
    Maker
    YFW
    Package
    SOD-123
    Pins
    2
    Source
    Manufacturer datasheet

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

  • MMSZ24SOD-123Zener diode, 2 pins, onsemiZener diodeSOD-1232 pinsonsemi
    What it is
    Zener diode
    Maker
    onsemi
    Package
    SOD-123
    Pins
    2
    Details
    Zener Voltage Regulators MMSZxxxT1G Series, SZMMSZxxxT1G Series
    Source
    Manufacturer datasheet

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

  • 3 more parts have no package on record
    • LD39030DTPU12RLDO regulator, STMicroelectronicsLDO regulatorNot recordedNot 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.

    • MM5Z39VBZener diode, Formosa MicrosemiZener diodeNot recordedNot recordedFormosa Microsemi
      What it is
      Zener diode
      Maker
      Formosa Microsemi
      Package
      Not recorded
      Pins
      Not recorded
      Source
      Manufacturer datasheet

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

    • MM5Z39VB-Q1Zener diode, Formosa MicrosemiZener diodeNot recordedNot recordedFormosa Microsemi
      What it is
      Zener diode
      Maker
      Formosa Microsemi
      Package
      Not recorded
      Pins
      Not recorded
      Source
      Manufacturer datasheet

      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.

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