SMD code 4Cs in SOT-23
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 4C was searched.
10 parts in SOT-23 are printed 4Cs
Not sure which one you have?
Answer up to 4 quick questions and these 38 parts are ranked, with a meter test that settles it. It works on a dead part too.
BC859CSOT-23Transistor, InfineonTransistorSOT-23Infineon
- What it is
- Transistor
- Maker
- Infineon
- Package
- SOT-23
- Pins
- 3
- Pinout
- 1 base
- 2 emitter
- 3 collector
- Details
- SMD General Purpose PNP Transistors
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Bipolar transistor.
BC859CLSOT-23PNP transistor, onsemiPNP transistorSOT-23onsemi
- What it is
- PNP transistor
- Maker
- onsemi
- Package
- SOT-23
- Pins
- 3
- Details
- General Purpose Transistors Series
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: PNP transistor.
PEC3824C2A-AUSOT-23ESD protection diode, PanjitESD protection diodeSOT-23Panjit
- What it is
- ESD protection diode
- Maker
- Panjit
- Package
- SOT-23
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
AD1584SOT-23Analog DevicesNot recordedSOT-23Analog Devices
- What it is
- Not recorded
- Maker
- Analog Devices
- Package
- SOT-23
- Pins
- 3
- Details
- 4.096 V Precision Series Mode Voltage Reference
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
FMMD3102SOT-23Diodes IncorporatedNot recordedSOT-23Diodes Incorporated
- What it is
- Not recorded
- Maker
- Diodes Incorporated
- Package
- SOT-23
- Pins
- 3
- Source
- Published code list
Is it dead? The meter test is below: This part.
FMMV3102SOT-23Not recordedSOT-23Not recorded
- What it is
- Not recorded
- Maker
- Not recorded
- Package
- SOT-23
- Pins
- 3
- Details
- C-diode: Tuning, 30V, 20..25pF, Q>300
- Source
- Published code list
Is it dead? The meter test is below: Silicon diode.
MMBV3102SOT-23onsemiNot recordedSOT-23onsemi
- What it is
- Not recorded
- Maker
- onsemi
- Package
- SOT-23
- Pins
- 3
- Details
- Hyperabrupt varicap
- Source
- Published code list
Is it dead? The meter test is below: PIN diode or varicap.
MMVB3102SOT-23onsemiNot recordedSOT-23onsemi
- What it is
- Not recorded
- Maker
- onsemi
- Package
- SOT-23
- Pins
- 3
- Details
- varicap 6-35pF
- Source
- Published code list
Is it dead? The meter test is below: PIN diode or varicap.
R3131N34ECSOT-23Nisshinbo Micro DevicesNot recordedSOT-23Nisshinbo Micro Devices
- What it is
- Not recorded
- Maker
- Nisshinbo Micro Devices
- Package
- SOT-23
- Pins
- 3
- Details
- CMOS-IC: Voltage Detector 3.4V, Reset Open drain output, 240ms
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
BC859CWSOT-323Transistor, YFWTransistorSOT-323YFW
- What it is
- Transistor
- Maker
- YFW
- Package
- SOT-323
- Pins
- 3
- Details
- SMD General Purpose PNP Transistors
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Bipolar transistor.
5 more parts have no package on record. Nothing rules them out, so they stay.
ESD8104MUESD protection diode, onsemiESD protection diodeNot recordedonsemi
- What it is
- ESD protection diode
- Maker
- onsemi
- Package
- Not recorded
- Pins
- Not recorded
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
GBLC24CDNESD protection diode, ProTek DevicesESD protection diodeNot recordedProTek Devices
- What it is
- ESD protection diode
- Maker
- ProTek Devices
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Ultra Low Capacitance TVS
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
NX5P2924CUKLoad switch, NXPLoad switchNot recordedNXP
- What it is
- Load switch
- Maker
- NXP
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Logic controlled high-side power switch
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Load switch.
SZESD8104MUESD protection diode, onsemiESD protection diodeNot recordedonsemi
- What it is
- ESD protection diode
- Maker
- onsemi
- Package
- Not recorded
- Pins
- Not recorded
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
TSCD034WTSchottky diode, Taitron ComponentsSchottky diodeNot recordedTaitron Components
- What it is
- Schottky diode
- Maker
- Taitron Components
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Low Profile Chip Type Schottky Rectifier
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Schottky 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.
Bipolar transistor
Diode range, part lifted or its base leg off the pad.
Working, it reads
From the base, one probe colour 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.
PNP transistor
Diode range, part lifted or its base leg off the pad.
Working, it reads
Black 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.
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.
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.
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.
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.
PIN diode or varicap
Diode range, part lifted or one leg off the pad. Red probe on the anode.
Working, it reads
About 0.6 to 0.9 V anode to cathode, 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.
- 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 varicap that has drifted in capacitance reads normal on a meter. Only a capacitance meter or the tuning itself shows it.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
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.
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.
Printed with a code easy to misread as 4Cs
One character differs, and it is one that is easy to confuse under a lamp. Each code has a page of its own.
Codes not listed here are printed on 13 more parts.
Did you find your part?
Open this in the search to correct a character or try another package.