SMD code P54
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.
P54 on a chip capacitor
0.54 pF
0.54 pF capacitor
The p is both the decimal point and the unit: 0.54 pF.
Check it with a meter
Lift one end and measure it on a capacitance range. A good one reads close to 0.54 pF. In circuit the meter also sees everything connected across it, so the reading means little until it is out. A failed one usually reads near 0 Ω, or a steady low resistance, on the ohms range, often from a crack. On the board a shorted capacitor shorts its whole rail. A failed reading does not change what to fit: the marking still says 0.54 pF.
On a transistor or diode body (SOT-23-5, SOT-89-5, SMA), P54 is a part code instead. Those parts are listed below.
5 parts are printed P54
Not sure which one you have?
Answer up to 4 quick questions and these 5 parts are ranked, with a meter test that settles it. It works on a dead part too.
PDTC143ZUSOT-323Digital transistor (NPN, resistors built in), 3 pins, NXPDigital transistor (NPN, resistors built in)SOT-3233 pinsNXP
- What it is
- Digital transistor (NPN, resistors built in)
- Maker
- NXP
- Package
- SOT-323
- Pins
- 3
- Details
- 50 V, 100 mA NPN resistor-equipped transistor; R1 = 4.7 kΩ, R2 = 47 kΩ
- Source
- Published code list
Is it dead? The meter test is below: Digital transistor.
XC6368E542MRSOT-23-5DC-DC converter, 5 pins, TorexDC-DC converterSOT-23-55 pinsTorex
- What it is
- DC-DC converter
- Maker
- Torex
- Package
- SOT-23-5
- Pins
- 5
- Details
- DC/DC voltage converter IC: PWM/PFM st-up, 5.4V±2.5%, 200mA, 180kHz, +CE
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
XC6382F541MSOT-23-5DC-DC converter, 5 pins, TorexDC-DC converterSOT-23-55 pinsTorex
- What it is
- DC-DC converter
- Maker
- Torex
- Package
- SOT-23-5
- Pins
- 5
- Details
- DC/DC voltage converter IC: PFM st-up, 5.4V±2.5%, 400mA, 100kHz, internal Vdd, ext. transistor
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
XC6382F541PSOT-89-5DC-DC converter, 5 pins, TorexDC-DC converterSOT-89-55 pinsTorex
- What it is
- DC-DC converter
- Maker
- Torex
- Package
- SOT-89-5
- Pins
- 5
- Details
- DC/DC voltage converter IC: PFM st-up, 5.4V±2.5%, 400mA, 100kHz, int. Vdd, ext. transis.
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
1 more part has no package on record
PCA955416 pins, NXPNot recordedNot recorded16 pinsNXP
- What it is
- Not recorded
- Maker
- NXP
- Package
- Not recorded
- Pins
- 16
- Details
- 8-bit I2C-bus and SMBus I/O port with interrupt
- Source
- Published code list
Is it dead? The meter test is below: This part.
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.
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.
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.
Printed with a code easy to misread as P54
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 P54
For a marking with its end worn or burnt off. Each code has a page of its own.
Did you find your part?
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