SMD code 8B in SMB
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.
1 part in SMB is printed 8B
Not sure which one you have?
Answer up to 4 quick questions and these 21 parts are ranked, with a meter test that settles it. It works on a dead part too.
SM6T7V5CASMBTVS diode, 2 pins, Fagor ElectronicaTVS diode2 pinsFagor Electronica
- What it is
- TVS diode
- Maker
- Fagor Electronica
- Package
- SMB
- Pins
- 2
- Details
- 600 W TVS diode, bidirectional
- Source
- Published code list
Is it dead? The meter test is below: TVS or ESD protection diode.
14 more parts have no package on record. Nothing rules them out, so they stay.
GSEZ8B450ESD protection diode, Good-ArkESD protection diodeNot recordedGood-Ark
- What it is
- ESD protection diode
- Maker
- Good-Ark
- Package
- Not recorded
- Pins
- Not recorded
- Details
- ESD protection diode, VRWM 8 V
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
LDTC124EET1GDigital transistor (NPN, resistors built in), LRCDigital transistor (NPN, resistors built in)Not recordedLRC
- What it is
- Digital transistor (NPN, resistors built in)
- Maker
- LRC
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Digital transistor (bias resistors built in), NPN, IC 100 mA, VCEO 50 V
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Digital transistor.
N08BT1006HESD protection diode, Formosa MicrosemiESD protection diodeNot recordedFormosa Microsemi
- What it is
- ESD protection diode
- Maker
- Formosa Microsemi
- Package
- Not recorded
- Pins
- Not recorded
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
AD5611ACPZ-RL76 pins, Analog DevicesNot recorded6 pinsAnalog Devices
- What it is
- Not recorded
- Maker
- Analog Devices
- Package
- Not recorded
- Pins
- 6
- Source
- Published code list
Is it dead? The meter test is below: This part.
AP7343D-09FS4-7BLDO regulator, Diodes IncorporatedLDO regulatorNot recordedDiodes Incorporated
- What it is
- LDO regulator
- Maker
- Diodes Incorporated
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Linear voltage regulator IC: LDO, 0.9V±1%, 300mA, +CE, CL
- Source
- Published code list
Is it dead? The meter test is below: Voltage regulator.
CDZ55C8V2TZener diode, Crownpo TechnologyZener diodeNot recordedCrownpo Technology
- What it is
- Zener diode
- Maker
- Crownpo Technology
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Zener diode: 7.79..8.61V, Zzt=7, Izt=5mA, 200mW
- Source
- Published code list
Is it dead? The meter test is below: Zener diode.
IXD5127C17DNRVoltage supervisor, IXYSVoltage supervisorNot recordedIXYS
- What it is
- Voltage supervisor
- Maker
- IXYS
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 1.7V±0.8%, -Reset PPO, -MR, 400ms Rt delay
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
IXD5127N17JNRVoltage supervisor, IXYSVoltage supervisorNot recordedIXYS
- What it is
- Voltage supervisor
- Maker
- IXYS
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 1.7V±0.8%, +Reset ODO, -MR, 400ms Rt delay
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
R1161D181ANisshinbo Micro DevicesNot recordedNot recordedNisshinbo Micro Devices
- What it is
- Not recorded
- Maker
- Nisshinbo Micro Devices
- Package
- Not recorded
- Pins
- Not recorded
- Details
- VR-IC: LDO, -CE, 1.8V±2%, 350mA
- Source
- Published code list
Is it dead? The meter test is below: Voltage regulator.
UN9212JPanNot recordedNot recordedPan
- What it is
- Not recorded
- Maker
- Pan
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Si-npn-Digi: Sw, 50V, 100mA, 125mW, 150MHz, R1/R2=22k/22k
- Source
- Published code list
Is it dead? The meter test is below: This part.
UNR9212JPanNot recordedNot recordedPan
- What it is
- Not recorded
- Maker
- Pan
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Si-npn-Digi: Sw, 50V, 100mA, 125mW, 150MHz, R1/R2=22k/22k
- Source
- Published code list
Is it dead? The meter test is below: This part.
XC6127C17DNRVoltage supervisor, TorexVoltage supervisorNot recordedTorex
- What it is
- Voltage supervisor
- Maker
- Torex
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 1.7V±0.8%, -Reset PPO, -MR, Rdt=400ms
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
XC6127N17JNRVoltage supervisor, TorexVoltage supervisorNot recordedTorex
- What it is
- Voltage supervisor
- Maker
- Torex
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 1.7V±0.8%, +Reset ODO, -MR, Rdt=400ms
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
XC6129C17J9R-GVoltage supervisor, TorexVoltage supervisorNot recordedTorex
- What it is
- Voltage supervisor
- Maker
- Torex
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 1.7V±0.8%,+Reset PPO, Detect Delay
- 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.
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.
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.
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.
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.
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 8B
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 1 more part.
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