SMD code 1Et 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, t, is lower case, which on NXP and Philips parts is a date or factory code, so it was set aside and 1E was searched.
34 parts in SOT-23 are printed 1Et
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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.
all SOT-23, 3 pins. What differs:
CMPT930SOT-23NPN transistor, HXYNPN transistorHXY
- What it is
- NPN transistor
- Maker
- HXY
- Package
- SOT-23
- Pins
- 3
- Details
- Bipolar transistor, 45 V, 0.1 A
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: NPN transistor.
EMBE0N10JSSOT-23N-channel MOSFET, Excelliance MOSN-channel MOSFETExcelliance MOS
- What it is
- N-channel MOSFET
- Maker
- Excelliance MOS
- Package
- SOT-23
- Pins
- 3
- Details
- 100 V, 0.9 A N-channel MOSFET
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: N-channel MOSFET.
IRLML6402TRSOT-23P-channel MOSFET, UMWP-channel MOSFETUMW
- What it is
- P-channel MOSFET
- Maker
- UMW
- Package
- SOT-23
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: P-channel MOSFET.
LBC847ALT1GSOT-23NPN transistor, LRCNPN transistorLRC
- What it is
- NPN transistor
- Maker
- LRC
- Package
- SOT-23
- Pins
- 3
- Details
- Bipolar transistor, NPN, IC 100 mA, VCEO 45 V
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: NPN transistor.
MMBT2412-QSOT-23NPN transistor, Good-ArkNPN transistorGood-Ark
- What it is
- NPN transistor
- Maker
- Good-Ark
- Package
- SOT-23
- Pins
- 3
- Details
- NPN transistor, 50 V, 0.15 A
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: NPN transistor.
S-LBC847ALT1GSOT-23NPN transistor, LRCNPN transistorLRC
- What it is
- NPN transistor
- Maker
- LRC
- Package
- SOT-23
- Pins
- 3
- Details
- Bipolar transistor, NPN, IC 100 mA, VCEO 45 V
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: NPN transistor.
TBC847ASOT-23NPN transistor, Galaxy MicroelectronicsNPN transistorGalaxy Microelectronics
- What it is
- NPN transistor
- Maker
- Galaxy Microelectronics
- Package
- SOT-23
- Pins
- 3
- Details
- 45V, 0.1A, General Purpose NPN Bipolar Transistor
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: NPN transistor.
CM9NB847ASOT-23NPN transistor, Canaan MicroelectronicsNPN transistorCanaan Microelectronics
- What it is
- NPN transistor
- Maker
- Canaan Microelectronics
- Package
- SOT-23
- Pins
- 3
- Details
- NPN transistor: AF, Sw, 50V, 100mA, 200mW, B=110..220, 100MHz
- Source
- Published code list
Is it dead? The meter test is below: NPN transistor.
FMMT-A43SOT-23Diodes IncorporatedNot recordedDiodes Incorporated
- What it is
- Not recorded
- Maker
- Diodes Incorporated
- Package
- SOT-23
- Pins
- 3
- Details
- equivalent MPSA43
- Source
- Published code list
Is it dead? The meter test is below: This part.
FMMTA43SOT-23Diodes IncorporatedNot recordedDiodes Incorporated
- What it is
- Not recorded
- Maker
- Diodes Incorporated
- Package
- SOT-23
- Pins
- 3
- Details
- Si-npn: 200V, 200mA, 330mW, B=50..200, >50MHz
- Source
- Published code list
Is it dead? The meter test is below: This part.
HABC847ASOT-23NPN transistor, Hottech ElectronicsNPN transistorHottech Electronics
- What it is
- NPN transistor
- Maker
- Hottech Electronics
- Package
- SOT-23
- Pins
- 3
- Details
- NPN transistor: GP, 50V, 100mA, 200mW, >100MHz, B=110..220
- Source
- Published code list
Is it dead? The meter test is below: NPN transistor.
IRLML6402SOT-23P-channel MOSFET, International RectifierP-channel MOSFETInternational Rectifier
- What it is
- P-channel MOSFET
- Maker
- International Rectifier
- Package
- SOT-23
- Pins
- 3
- Details
- P-channel MOSFET, 20 V, 4.2 A
- Source
- Published code list
Is it dead? The meter test is below: P-channel MOSFET.
KST43SOT-23FairchildNot recordedFairchild
- What it is
- Not recorded
- Maker
- Fairchild
- Package
- SOT-23
- Pins
- 3
- Details
- Si-npn: Vid, 200V, 500mA, 350mW, B>40, >50MHz
- Source
- Published code list
Is it dead? The meter test is below: This part.
KST43MTFSOT-23onsemiNot recordedonsemi
- What it is
- Not recorded
- Maker
- onsemi
- Package
- SOT-23
- Pins
- 3
- Details
- General purpose NPN Transistor
- Source
- Published code list
Is it dead? The meter test is below: Bipolar transistor.
MMBTA43SOT-23NPN transistor, ITT IntermetallNPN transistorITT Intermetall
- What it is
- NPN transistor
- Maker
- ITT Intermetall
- Package
- SOT-23
- Pins
- 3
- Details
- 200V, 0.5A, General Purpose NPN Bipolar Transistor
- Source
- Published code list
Is it dead? The meter test is below: NPN transistor.
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.
NPN transistor
Diode range, part lifted or its base leg off the pad.
Working, it reads
Red 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.
N-channel MOSFET
Diode range, part lifted. Test drain to source first, then short gate to source and test again.
Working, it reads
Red probe on the source, black on the drain: about 0.4 to 0.9 V, the body diode. Open the other way. The gate reads open to both other pins, both ways.
Dead, it reads
- Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
- The gate reads low to source or drain: gate shorted. Often all three pins end up shorted together.
- No body diode at all: failed open.
- On the board
- the gate usually has a resistor to the source, so gate to source reads that resistor, which is not a fault. A drain short can be the load. Lift a leg to be sure.
- 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 diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
P-channel MOSFET
Diode range, part lifted. Test drain to source first, then short gate to source and test again.
Working, it reads
Red probe on the drain, black on the source: about 0.4 to 0.9 V, the body diode. Open the other way. The gate reads open to both other pins, both ways.
Dead, it reads
- Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
- The gate reads low to source or drain: gate shorted. Often all three pins end up shorted together.
- No body diode at all: failed open.
- On the board
- the gate usually has a resistor to the source, so gate to source reads that resistor, which is not a fault. Lift a leg to be sure.
- 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 diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.
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.
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.
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