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SMD code 54-

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.

92 parts are printed 54-

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.

  • SOD54ASOD-123TVS diode, 2 pins, WeEn SemiconductorsTVS diodeSOD-1232 pinsWeEn Semiconductors
    What it is
    TVS diode
    Maker
    WeEn Semiconductors
    Package
    SOD-123
    Pins
    2
    Source
    Manufacturer datasheet

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

  • TDTA114YCASOT-23Digital transistor (PNP, resistors built in), 3 pins, Galaxy MicroelectronicsDigital transistor (PNP, resistors built in)SOT-233 pinsGalaxy Microelectronics
    What it is
    Digital transistor (PNP, resistors built in)
    Maker
    Galaxy Microelectronics
    Package
    SOT-23
    Pins
    3
    Details
    50V, 70mA, PNP Bipolar Digital Transistor
    Source
    Manufacturer datasheet

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

  • TDTA114YESOT-523Digital transistor (PNP, resistors built in), 3 pins, Galaxy MicroelectronicsDigital transistor (PNP, resistors built in)SOT-5233 pinsGalaxy Microelectronics
    What it is
    Digital transistor (PNP, resistors built in)
    Maker
    Galaxy Microelectronics
    Package
    SOT-523
    Pins
    3
    Details
    50V, 70mA, PNP Bipolar Digital Transistor
    Source
    Manufacturer datasheet

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

  • TDTA114YLSOT-883Digital transistor (PNP, resistors built in), 3 pins, Galaxy MicroelectronicsDigital transistor (PNP, resistors built in)SOT-8833 pinsGalaxy Microelectronics
    What it is
    Digital transistor (PNP, resistors built in)
    Maker
    Galaxy Microelectronics
    Package
    SOT-883
    Pins
    3
    Details
    -50V, -70mA, PNP Bipolar Digital Transistor
    Source
    Manufacturer datasheet

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

  • TDTA114YMSOT-723Digital transistor (PNP, resistors built in), 3 pins, Galaxy MicroelectronicsDigital transistor (PNP, resistors built in)SOT-7233 pinsGalaxy Microelectronics
    What it is
    Digital transistor (PNP, resistors built in)
    Maker
    Galaxy Microelectronics
    Package
    SOT-723
    Pins
    3
    Details
    50V, 70mA, PNP Bipolar Digital Transistor
    Source
    Manufacturer datasheet

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

  • TDTA114YUASOT-323Digital transistor (PNP, resistors built in), 3 pins, Galaxy MicroelectronicsDigital transistor (PNP, resistors built in)SOT-3233 pinsGalaxy Microelectronics
    What it is
    Digital transistor (PNP, resistors built in)
    Maker
    Galaxy Microelectronics
    Package
    SOT-323
    Pins
    3
    Details
    50V, 70mA, PNP Bipolar Digital Transistor
    Source
    Manufacturer datasheet

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

  • TPM27524A-DFSRDFN8 pins, 3PEAKNot recordedDFN8 pins3PEAK
    What it is
    Not recorded
    Maker
    3PEAK
    Package
    DFN
    Pins
    8
    Details
    Dual 5-A High-speed, Low-side Gate Driver
    Source
    Manufacturer datasheet

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

  • WNMD2154-6SOT-563N-channel MOSFET, 6 pins, WillsemiN-channel MOSFETSOT-5636 pinsWillsemi
    What it is
    N-channel MOSFET
    Maker
    Willsemi
    Package
    SOT-563
    Pins
    6
    Source
    Manufacturer datasheet

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

  • EIA-96:540603Precision resistor (EIA-96 code), 2 pinsPrecision resistor (EIA-96 code)06032 pinsNot recorded
    What it is
    Precision resistor (EIA-96 code)
    Maker
    Not recorded
    Package
    0603
    Pins
    2
    Details
    EIA-96 precision chip resistor, code 54 stands for 357 in the E96 table; the printed mark adds a multiplier letter (54A = 357 Ohm, 54B = 3.57 kOhm)
    Source
    Added by hand from a published table

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

  • 6 more parts have no package on record
    • SGM2572CDYGLoad switch, 4 pins, SG MicroLoad switchNot recorded4 pinsSG Micro
      What it is
      Load switch
      Maker
      SG Micro
      Package
      Not recorded
      Pins
      4
      Details
      5.5V, 2A, 34mΩ RON Load Switch with Reverse Current Protection
      Source
      Manufacturer datasheet

      Is it dead? The meter test is below: Load switch.

    • TAV1-541+RF amplifier (MMIC), Mini-CircuitsRF amplifier (MMIC)Not recordedNot recordedMini-Circuits
      What it is
      RF amplifier (MMIC)
      Maker
      Mini-Circuits
      Package
      Not recorded
      Pins
      Not recorded
      Details
      MMIC amplifier, 0.045-6 GHz
      Source
      Manufacturer datasheet

      Is it dead? The meter test is below: RF amplifier.

    • 74AUP1G74GFNXPNot recordedNot recordedNot recordedNXP
      What it is
      Not recorded
      Maker
      NXP
      Package
      Not recorded
      Pins
      Not recorded
      Details
      CMOS logic IC: Positive edge-triggered D-type flip-flop with set and reset
      Source
      Published code list

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

    • 74AUP1G74GNNXPNot recordedNot recordedNot recordedNXP
      What it is
      Not recorded
      Maker
      NXP
      Package
      Not recorded
      Pins
      Not recorded
      Details
      CMOS logic IC: Positive edge-triggered D-type flip-flop with set and reset
      Source
      Published code list

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

    • 74AUP1G74GSNXPNot recordedNot recordedNot recordedNXP
      What it is
      Not recorded
      Maker
      NXP
      Package
      Not recorded
      Pins
      Not recorded
      Details
      CMOS logic IC: Positive edge-triggered D-type flip-flop with set and reset
      Source
      Published code list

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

    • 74AUP1G74GXNXPNot recordedNot recordedNot recordedNXP
      What it is
      Not recorded
      Maker
      NXP
      Package
      Not recorded
      Pins
      Not recorded
      Details
      CMOS logic IC: Positive edge-triggered D-type flip-flop with set and reset
      Source
      Published code list

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

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.

Load switch

Voltage, board powered, black probe on ground.

Working, it reads

Switched on, the output pin sits at the input voltage. Switched off, it sits near 0 V.

Dead, it reads

  • Output at the input voltage while switched off: the pass element has shorted.
  • Input present and switched on, no output: failed open, or shut down into a shorted load. Power off and measure output to ground.
On the board:
An output near 0 Ω to ground is usually the load. Lift the output pin to see which.
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 pinout and whether the enable is active high or low differ between parts. The datasheet gives both.

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.

RF amplifier

Voltage, board powered, on the output pin that the bias resistor or choke feeds.

Working, it reads

The output pin sits at the device voltage the datasheet gives, a few volts, below the supply.

Dead, it reads

  • Output pin at 0 V, or near 0 Ω to ground with the power off: shorted inside.
  • Output pin at the full supply voltage: open inside, no current flowing.
On the board:
Measured on the board with power on; the bias network is part of the reading.
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 figures depend on the part and its bias resistor. The datasheet gives both.

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.

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.

N-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 source, black on the drain: 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. A drain short can be the load. 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.

Resistor

Ohms range, across it, power off.

Working, it reads

Its marked value, within tolerance. On the board it reads the same or lower, because everything around it sits in parallel.

Dead, it reads

  • Open: burnt, cracked, or eaten through by sulphur. The commonest failure.
  • Well above its marked value: drifted high.
  • On the board, clearly higher than its marked value: it has failed, since the board can only pull a reading down.
On the board:
A reading lower than marked on the board proves nothing; lift one end. A reading higher than marked is a fault even on the board.
Compare:
The same position on another channel usually carries the same value, and so does the matching part on another board.
Watch for:
A burnt resistor usually means the part it feeds pulled too much. Find that before fitting a new one, or it burns too. The marking, not the reading, says what to fit.

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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