SMD code 12D
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.
12D on a chip resistor
130 kΩ
130 kΩ resistor, 1%
EIA-96 precision code: 12 stands for 130 in the E96 table, and the letter D is the multiplier, × 1 000. These are 1% parts.
Check it with a meter
Lift one end and measure across it. A good one reads 130 kΩ within 1%. Measuring it in circuit reads the parallel combination of everything around it, which is almost always lower, never higher: well above 130 kΩ on the board is a fault. Open, or well above 130 kΩ, means it has failed: burnt, cracked or corroded. That does not change what to fit: the marking still says 130 kΩ. 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-23-5, SOT-23, SMB), 12D is a part code instead. Those parts are listed below.
22 parts are printed 12D
Not sure which one you have?
Answer up to 4 quick questions and these 22 parts are ranked, with a meter test that settles it. It works on a dead part too.
ESD12VDHDFN1610-2ESD protection diode, 2 pins, Galaxy MicroelectronicsESD protection diodeDFN1610-22 pinsGalaxy Microelectronics
- What it is
- ESD protection diode
- Maker
- Galaxy Microelectronics
- Package
- DFN1610-2
- Pins
- 2
- Details
- 4.5V, 1500W, Surface Mount TVS
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
ESD12VDH-HFDFN1610-2ESD protection diode, 2 pins, ComchipESD protection diodeDFN1610-22 pinsComchip
- What it is
- ESD protection diode
- Maker
- Comchip
- Package
- DFN1610-2
- Pins
- 2
- Details
- 12 V unidirectional ESD protection diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
S-LESD23H12CLT1GSOT-23ESD protection diode, 3 pins, LRCESD protection diodeSOT-233 pinsLRC
- What it is
- ESD protection diode
- Maker
- LRC
- Package
- SOT-23
- Pins
- 3
- Details
- ESD protection diode, VRWM 12 V, IR @VRWM 0.1 μA, VBR Min 13 V
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
APR3012-26ASOT-233 pins, AnpecNot recordedSOT-233 pinsAnpec
- What it is
- Not recorded
- Maker
- Anpec
- Package
- SOT-23
- Pins
- 3
- Details
- CMOS-IC: Voltage detector, 2.63V, Reset Push-pull output
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
APR3012-26BSOT-23-55 pins, AnpecNot recordedSOT-23-55 pinsAnpec
- What it is
- Not recorded
- Maker
- Anpec
- Package
- SOT-23-5
- Pins
- 5
- Details
- CMOS-IC: Voltage detector, 2.63V, Reset Push-pull output
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
APR3012-26DSOT-893 pins, AnpecNot recordedSOT-893 pinsAnpec
- What it is
- Not recorded
- Maker
- Anpec
- Package
- SOT-89
- Pins
- 3
- Details
- CMOS-IC: Voltage detector, 2.63V, Reset Push-pull output
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
IXD1503P25APR-GSOT-89LDO regulator, 3 pins, IXYSLDO regulatorSOT-893 pinsIXYS
- What it is
- LDO regulator
- Maker
- IXYS
- Package
- SOT-89
- Pins
- 3
- Details
- Linear voltage regulator IC: LDO, 2.55V±1%, 500mA
- Source
- Published code list
Is it dead? The meter test is below: Voltage regulator.
MAZL120DSOT-23-5Zener diode, 5 pins, PanasonicZener diodeSOT-23-55 pinsPanasonic
- What it is
- Zener diode
- Maker
- Panasonic
- Package
- SOT-23-5
- Pins
- 5
- Details
- Zener diode: Quad, 12V, Zzt=30 (5mA), 200mW
- Source
- Published code list
Is it dead? The meter test is below: Zener diode.
P4SMAFJ12CASMAFTVS diode, 2 pins, Dongguan You Feng Wei ElectronicsTVS diodeSMAF2 pinsDongguan You Feng Wei Electronics
- What it is
- TVS diode
- Maker
- Dongguan You Feng Wei Electronics
- Package
- SMAF
- Pins
- 2
- Details
- Transient voltage supressor: Vrwm=12V, Vbr=13.3..15.3V, Ipp=20.1A, 400W(1ms), Bidir.
- Source
- Published code list
Is it dead? The meter test is below: TVS or ESD protection diode.
P4SMAJ12CASMA2 pins, YeashinNot recordedSMA2 pinsYeashin
- What it is
- Not recorded
- Maker
- Yeashin
- Package
- SMA
- Pins
- 2
- Details
- TVS: 12V, 20.1A, 400W(1ms), Bidirectional
- Source
- Published code list
Is it dead? The meter test is below: TVS or ESD protection diode.
P4SMFJ12CASOD-123FTVS diode, 2 pins, YeashinTVS diodeSOD-123F2 pinsYeashin
- What it is
- TVS diode
- Maker
- Yeashin
- Package
- SOD-123F
- Pins
- 2
- Details
- Transient voltage supressor: Vrwm=12V, Ipp=20.1A, 400W (1ms), Bidir.
- Source
- Published code list
Is it dead? The meter test is below: TVS or ESD protection diode.
R1182N231DSOT-23-55 pins, Nisshinbo Micro DevicesNot recordedSOT-23-55 pinsNisshinbo Micro Devices
- What it is
- Not recorded
- Maker
- Nisshinbo Micro Devices
- Package
- SOT-23-5
- Pins
- 5
- Details
- VR-IC: LDO, CE, auto discharge, 2.3V±2%, 150mA
- Source
- Published code list
Is it dead? The meter test is below: Voltage regulator.
RB491DSOT-23Schottky diode, 3 pins, PanjitSchottky diodeSOT-233 pinsPanjit
- What it is
- Schottky diode
- Maker
- Panjit
- Package
- SOT-23
- Pins
- 3
- Details
- Schottky diode, 20 V, 1 A
- Source
- Published code list
Is it dead? The meter test is below: Schottky diode.
2 more parts have no package on record
ESD5Z12CESD protection diode, Formosa MicrosemiESD protection diodeNot recordedNot 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.
LESD23H12CLT1GESD 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 0.1 μA, VBR Min 13 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.
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.
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.
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 12D
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 36 more parts.
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