SMD code QI- in SOT-323

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.

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.

Nothing is printed exactly QI-

These parts are printed with a character that is easy to misread as what you typed. The odd one out is marked on each.

all SOT-323, 3 pins. What differs:

CHT2301WGPprinted 01SOT-323P-channel MOSFET, ChenmkoP-channel MOSFETChenmko
Printed 01 on the part. Easy to misread as QI-. Check that character with a loupe before you order anything.
What it is
P-channel MOSFET
Maker
Chenmko
Package
SOT-323
Pins
3
Details
P-Channel Enhancement Mode Field Effect Transistor, 20 V, 2.3 A
Source
Manufacturer datasheet
Is it dead? The meter test is below: P-channel MOSFET.
Datasheetfor CHT2301WGP, opens in a new tab
MMBD4448Wprinted Q1SOT-323Switching diode, Formosa MicrosemiSwitching diodeFormosa Microsemi
Printed Q1 on the part. Easy to misread as QI-. Check that character with a loupe before you order anything.
What it is
Switching diode
Maker
Formosa Microsemi
Package
SOT-323
Pins
3
Source
Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
Datasheetfor MMBD4448W, opens in a new tab
MMBZ5226BWprinted D1SOT-323Zener diode, DC ComponentsZener diodeDC Components
Printed D1 on the part. Easy to misread as QI-. Check that character with a loupe before you order anything.
What it is
Zener diode
Maker
DC Components
Package
SOT-323
Pins
3
Source
Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
Datasheetfor MMBZ5226BW, opens in a new tab
PDTA143EUprinted 01SOT-323Digital transistor (PNP, resistors built in), NexperiaDigital transistor (PNP, resistors built in)Nexperia
Printed 01 on the part. Easy to misread as QI-. Check that character with a loupe before you order anything.
What it is
Digital transistor (PNP, resistors built in)
Maker
Nexperia
Package
SOT-323
Pins
3
Details
50 V, 100 mA PNP resistor-equipped transistor; R1 = 4.7 kΩ, R2 = 4.7 kΩ
Source
Manufacturer datasheet
Is it dead? The meter test is below: Digital transistor.
Datasheetfor PDTA143EU, opens in a new tab
SM1401PSSprinted 01SOT-323P-channel MOSFET, Sinopower SemiconductorP-channel MOSFETSinopower Semiconductor
Printed 01 on the part. Easy to misread as QI-. Check that character with a loupe before you order anything.
What it is
P-channel MOSFET
Maker
Sinopower Semiconductor
Package
SOT-323
Pins
3
Details
20 V, 3.3 A P-channel MOSFET
Source
Manufacturer datasheet
Is it dead? The meter test is below: P-channel MOSFET.
Datasheetfor SM1401PSS, opens in a new tab
2SC4117-BLprinted DLSOT-323NPN transistor, ToshibaNPN transistorToshiba
Printed DL on the part. Easy to misread as QI-. Check that character with a loupe before you order anything.
What it is
NPN transistor
Maker
Toshiba
Package
SOT-323
Pins
3
Details
Si-npn: AF-Amp, 120V, 100mA, 100mW, 100MHz, B=350..700
Source
Published code list
Is it dead? The meter test is below: NPN transistor.
2SC4117BLprinted DLSOT-323ToshibaNot recordedToshiba
Printed DL on the part. Easy to misread as QI-. Check that character with a loupe before you order anything.
What it is
Not recorded
Maker
Toshiba
Package
SOT-323
Pins
3
Source
Published code list
Is it dead? The meter test is below: This part.
2SC4261printed QI-SOT-323RF transistor, RenesasRF transistorRenesas
Printed QI- on the part. Easy to misread as QI-. Check that character with a loupe before you order anything.
What it is
RF transistor
Maker
Renesas
Package
SOT-323
Pins
3
Details
Si-npn: VHF/UHF, 25V, 50mA, 100mW, B=50..180, >1.8GHz
Source
Published code list
Is it dead? The meter test is below: Bipolar transistor.
2SC5343U-Lprinted DLSOT-323NPN transistor, AUK SemiconductorNPN transistorAUK Semiconductor
Printed DL on the part. Easy to misread as QI-. Check that character with a loupe before you order anything.
What it is
NPN transistor
Maker
AUK Semiconductor
Package
SOT-323
Pins
3
Details
NPN transistor: GP, 60V, 150mA, 200mW, >80MHz, B=300..700
Source
Published code list
Is it dead? The meter test is below: NPN transistor.
AP8821C-31GTprinted D1SOT-323Voltage supervisor, Anwell SemiconductorVoltage supervisorAnwell Semiconductor
Printed D1 on the part. Easy to misread as QI-. Check that character with a loupe before you order anything.
What it is
Voltage supervisor
Maker
Anwell Semiconductor
Package
SOT-323
Pins
3
Details
Voltage detector IC: 3.1V±2%, -Reset PPO, H-free
Source
Published code list
Is it dead? The meter test is below: Integrated circuit.
AP8821C-31PTprinted D1SOT-323Voltage supervisor, Anwell SemiconductorVoltage supervisorAnwell Semiconductor
Printed D1 on the part. Easy to misread as QI-. Check that character with a loupe before you order anything.
What it is
Voltage supervisor
Maker
Anwell Semiconductor
Package
SOT-323
Pins
3
Details
Voltage detector IC: 3.1V±2%, -Reset PPO
Source
Published code list
Is it dead? The meter test is below: Integrated circuit.
AP8822C-41GTprinted 01SOT-323Voltage supervisor, Anwell SemiconductorVoltage supervisorAnwell Semiconductor
Printed 01 on the part. Easy to misread as QI-. Check that character with a loupe before you order anything.
What it is
Voltage supervisor
Maker
Anwell Semiconductor
Package
SOT-323
Pins
3
Details
Voltage detector IC: 4.1V±2%, -Reset PPO, Rdt=200ms, H-free
Source
Published code list
Is it dead? The meter test is below: Integrated circuit.
AP8822C-41PTprinted 01SOT-323Voltage supervisor, Anwell SemiconductorVoltage supervisorAnwell Semiconductor
Printed 01 on the part. Easy to misread as QI-. Check that character with a loupe before you order anything.
What it is
Voltage supervisor
Maker
Anwell Semiconductor
Package
SOT-323
Pins
3
Details
Voltage detector IC: 4.1V±2%, -Reset PPO, Rdt=200ms
Source
Published code list
Is it dead? The meter test is below: Integrated circuit.
EC95808C31C1Nprinted D1SOT-323Voltage supervisor, E-CMOSVoltage supervisorE-CMOS
Printed D1 on the part. Easy to misread as QI-. Check that character with a loupe before you order anything.
What it is
Voltage supervisor
Maker
E-CMOS
Package
SOT-323
Pins
3
Details
Voltage detector IC: 3.1V±2%, -Reset PPO
Source
Published code list
Is it dead? The meter test is below: Integrated circuit.
EC95810C41C1Nprinted 01SOT-323Voltage supervisor, E-CMOSVoltage supervisorE-CMOS
Printed 01 on the part. Easy to misread as QI-. Check that character with a loupe before you order anything.
What it is
Voltage supervisor
Maker
E-CMOS
Package
SOT-323
Pins
3
Details
Voltage detector IC: 4.1V±2%, -Reset PPO, Rdt=200ms
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.

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.

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.

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.

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.

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.

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.

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.

Codes that begin with QI-

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 4,008 more parts.

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