SMD code B3-
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.
199 parts are printed B3-
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.
MM3Z47BWSOD-323Zener diode, 2 pins, YFWZener diodeSOD-3232 pinsYFW
- What it is
- Zener diode
- Maker
- YFW
- Package
- SOD-323
- Pins
- 2
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
MMBD717LSOT-323Schottky diode, 3 pins, onsemiSchottky diodeSOT-3233 pinsonsemi
- What it is
- Schottky diode
- Maker
- onsemi
- Package
- SOT-323
- Pins
- 3
- Details
- Common Anode Schottky Barrier Diodes
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Schottky diode.
PESD5V0U1BBSOD-523TVS diode, 2 pins, UMWTVS diodeSOD-5232 pinsUMW
- What it is
- TVS diode
- Maker
- UMW
- Package
- SOD-523
- Pins
- 2
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
PTVS60VS1UR-MSSOD-123FTVS diode, 2 pins, MSKSEMITVS diodeSOD-123F2 pinsMSKSEMI
- What it is
- TVS diode
- Maker
- MSKSEMI
- Package
- SOD-123F
- Pins
- 2
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
PUMB1SOT-363Digital transistor (PNP, resistors built in), 6 pins, NexperiaDigital transistor (PNP, resistors built in)SOT-3636 pinsNexperia
- What it is
- Digital transistor (PNP, resistors built in)
- Maker
- Nexperia
- Package
- SOT-363
- Pins
- 6
- Details
- 50 V, 100 mA PNP/PNP resistor-equipped transistor; R1 = 22 kΩ, R2 = 22 kΩ
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Digital transistor.
PUMD30SOT-363Digital transistor (PNP, resistors built in), 6 pins, NexperiaDigital transistor (PNP, resistors built in)SOT-3636 pinsNexperia
- What it is
- Digital transistor (PNP, resistors built in)
- Maker
- Nexperia
- Package
- SOT-363
- Pins
- 6
- Details
- 50 V, 100 mA NPN/PNP resistor-equipped double transistor; R1 = 2.2 kΩ, R2 = open
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Digital transistor.
RBS3LAM40CSOD-128Schottky diode, 2 pins, ROHMSchottky diodeSOD-1282 pinsROHM
- What it is
- Schottky diode
- Maker
- ROHM
- Package
- SOD-128
- Pins
- 2
- Details
- Schottky Barrier Diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Schottky diode.
S-L1SS184LT1GSOT-23Switching diode, 3 pins, LRCSwitching diodeSOT-233 pinsLRC
- What it is
- Switching diode
- Maker
- LRC
- Package
- SOT-23
- Pins
- 3
- Details
- Switching diode, VR 80 V, IF 100 mA, VF Max 1.2 V
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
S-LMBR0530T1GSOD-123Schottky diode, 2 pins, LRCSchottky diodeSOD-1232 pinsLRC
- What it is
- Schottky diode
- Maker
- LRC
- Package
- SOD-123
- Pins
- 2
- Details
- Schottky diode, VR 30 V, IF 0.5 A, VF Max 0.45 V
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Schottky diode.
SCS184KSOT-23Switching diode, 3 pins, SeCoSSwitching diodeSOT-233 pinsSeCoS
- What it is
- Switching diode
- Maker
- SeCoS
- Package
- SOT-23
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
SOD153-SHSOD-123FRectifier, 2 pins, LRCRectifierSOD-123F2 pinsLRC
- What it is
- Rectifier
- Maker
- LRC
- Package
- SOD-123F
- Pins
- 2
- Details
- Rectifier, VPK 200 V, IO @ TL 1.5 A, TL@°C 75
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
SS0530SOD-123Schottky diode, 2 pins, PanjitSchottky diodeSOD-1232 pinsPanjit
- What it is
- Schottky diode
- Maker
- Panjit
- Package
- SOD-123
- Pins
- 2
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Schottky diode.
3 more parts have no package on record
NC7SZ86FHLogic gate, onsemiLogic gateNot recordedNot recordedonsemi
- What it is
- Logic gate
- Maker
- onsemi
- Package
- Not recorded
- Pins
- Not recorded
- Details
- TinyLogic UHS Two-Input Exclusive-OR Gate
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
NC7SZ86L6Logic gate, onsemiLogic gateNot recordedNot recordedonsemi
- What it is
- Logic gate
- Maker
- onsemi
- Package
- Not recorded
- Pins
- Not recorded
- Details
- TinyLogic UHS Two-Input Exclusive-OR Gate
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
S-LTVS16H12T5GESD protection diode, LRCESD protection diodeNot recordedNot recordedLRC
- What it is
- ESD protection diode
- Maker
- LRC
- Package
- Not recorded
- Pins
- Not recorded
- Details
- ESD protection diode, VRWM 12 V, IR @VRWM 0.5 μA, VBR Min 13.5 V
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection 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.
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.
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.
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.
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.
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.
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