SMD code R2 in SOT-343
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.
R2 on a chip resistor
0.2 Ω
0.2 Ω resistor
The R stands in for the decimal point, which is how sub-ohm and fractional values are printed.
Check it with a meter
Lift one end and measure across it. A good one reads 0.2 Ω. Measuring it in circuit reads the parallel combination of everything around it, which is almost always lower, never higher: well above 0.2 Ω on the board is a fault. Open, or well above 0.2 Ω, means it has failed: burnt, cracked or corroded. That does not change what to fit: the marking still says 0.2 Ω. A burnt resistor usually means the part it feeds drew too much, so find that before fitting a new one.
On a transistor or diode body (SOT-23, SOT-23-5, SOT-89), R2 is a part code instead. Those parts are listed below.
4 parts in SOT-343 are printed R2
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.
BFP620SOT-343RF transistor, 4 pins, InfineonRF transistor4 pinsInfineon
- What it is
- RF transistor
- Maker
- Infineon
- Package
- SOT-343
- Pins
- 4
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Bipolar transistor.
R3111Q521ASOT-3434 pins, RicohNot recorded4 pinsRicoh
- What it is
- Not recorded
- Maker
- Ricoh
- Package
- SOT-343
- Pins
- 4
- Details
- CMOS-IC: Voltage Detector 5,2V±2.0%, Reset Push-pull output
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
R3116Q091CSOT-343Voltage supervisor, 4 pins, RicohVoltage supervisor4 pinsRicoh
- What it is
- Voltage supervisor
- Maker
- Ricoh
- Package
- SOT-343
- Pins
- 4
- Details
- Voltage detector IC: 0.9V±0.8%, -Reset PPO
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
RP104Q151DSOT-343LDO regulator, 4 pins, RicohLDO regulator4 pinsRicoh
- What it is
- LDO regulator
- Maker
- Ricoh
- Package
- SOT-343
- Pins
- 4
- Details
- Linear voltage regulator IC: LDO, 1.5V±0.8%, 150mA, +CE, CL
- Source
- Published code list
Is it dead? The meter test is below: Voltage regulator.
11 more parts have no package on record. Nothing rules them out, so they stay.
ESDA08CPESD protection diode, LeiditechESD protection diodeNot recordedLeiditech
- What it is
- ESD protection diode
- Maker
- Leiditech
- Package
- Not recorded
- Pins
- Not recorded
- Details
- ESD protection diode, VRWM 8 V, Cj 7 pF
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
NUF4220MNESD protection diode, onsemiESD protection diodeNot recordedonsemi
- What it is
- ESD protection diode
- Maker
- onsemi
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Audio EMI Filter, 4 Line, with ESD Protection
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
VS12VUD1HSESD protection diode, ROHMESD protection diodeNot recordedROHM
- What it is
- ESD protection diode
- Maker
- ROHM
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Transient Voltage Suppressor
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
BD46E262G-MVoltage supervisor, ROHMVoltage supervisorNot recordedROHM
- What it is
- Voltage supervisor
- Maker
- ROHM
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 2.6V±1%, -MR, -Reset PPO, Rdt=200ms
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
BFP620FRF transistor, 4 pins, InfineonRF transistor4 pinsInfineon
- What it is
- RF transistor
- Maker
- Infineon
- Package
- Not recorded
- Pins
- 4
- Source
- An older or alternative marking, from a published code list
Is it dead? The meter test is below: Bipolar transistor.
DW84C5V1NND03Zener diode, JSCJZener diodeNot recordedJSCJ
- What it is
- Zener diode
- Maker
- JSCJ
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Zener diode: 5.1V±10%, If=10mA, 150mW
- Source
- Published code list
Is it dead? The meter test is below: Zener diode.
ELM9732CAAVoltage supervisor, ELMVoltage supervisorNot recordedELM
- What it is
- Voltage supervisor
- Maker
- ELM
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
FP6802-27CC8GVoltage supervisor, FitipowerVoltage supervisorNot recordedFitipower
- What it is
- Voltage supervisor
- Maker
- Fitipower
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 2.7V±-2%, -Reset PPO
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
ISL9016IRUGCZ-T6 pins, RenesasNot recorded6 pinsRenesas
- What it is
- Not recorded
- Maker
- Renesas
- Package
- Not recorded
- Pins
- 6
- Details
- equivalent [2.7/1.8V Dual LDO]
- Source
- Published code list
Is it dead? The meter test is below: Voltage regulator.
IXD1504A421NR-GLDO regulator, IXYSLDO regulatorNot recordedIXYS
- What it is
- LDO regulator
- Maker
- IXYS
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Linear voltage regulator IC: LDO, 4.2V±1%, 150mA, +CE
- Source
- Published code list
Is it dead? The meter test is below: Voltage regulator.
R5426D124CANisshinbo Micro DevicesNot recordedNot recordedNisshinbo Micro Devices
- What it is
- Not recorded
- Maker
- Nisshinbo Micro Devices
- Package
- Not recorded
- Pins
- Not recorded
- Details
- CMOS-IC: Li-Ion Battery Over-charge/discharge Protection, Vc/d=1,24V
- 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.
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.
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.
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.
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.
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.
Printed with a code easy to misread as R2
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 R2
For a marking with its end worn or burnt off. Each code has a page of its own.
Codes not listed here are printed on 86 more parts.
Did you find your part?
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