SMD code QI- 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.
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.
15 parts have no package on record. Nothing rules them out, so they stay.
MTP2301V3printed 01P-channel MOSFET, CYStekP-channel MOSFETNot recordedCYStek
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
- CYStek
- Package
- Not recorded
- Pins
- Not recorded
- Details
- -20 V, -3.4 A P-channel MOSFET
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: P-channel MOSFET.
2SC5277-1printed D1Sanyo ElectricNot recordedNot recordedSanyo Electric
Printed D1 on the part. Easy to misread as QI-. Check that character with a loupe before you order anything.
- What it is
- Not recorded
- Maker
- Sanyo Electric
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Si-npn: UHF-S-band, 20V, 30mA, 100mW, B=60..120, 11GHz
- Source
- Published code list
Is it dead? The meter test is below: This part.
2SC5343UF-Lprinted DLNPN transistor, AUK SemiconductorNPN transistorNot recordedAUK 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
- Not recorded
- Pins
- Not recorded
- 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.
2SD1626printed DISanyo ElectricNot recordedNot recordedSanyo Electric
Printed DI on the part. Easy to misread as QI-. Check that character with a loupe before you order anything.
- What it is
- Not recorded
- Maker
- Sanyo Electric
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Si-npn-Darl: Drv, 80V, 1,5A, 500mW, B>4000, 120MHz
- Source
- Published code list
Is it dead? The meter test is below: This part.
2SD2099printed DLSanyo ElectricNot recordedNot recordedSanyo Electric
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
- Sanyo Electric
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Si-npn-Dg+D: Mtr-Drv, 40V, 3A, 1,5W, B>70, 100KHz, R1=90Ω, R2=800Ω
- Source
- Published code list
Is it dead? The meter test is below: This part.
74AUP1G00FW5printed Q1Diodes IncorporatedNot recordedNot recordedDiodes Incorporated
Printed Q1 on the part. Easy to misread as QI-. Check that character with a loupe before you order anything.
- What it is
- Not recorded
- Maker
- Diodes Incorporated
- Package
- Not recorded
- Pins
- Not recorded
- Details
- CMOS logic IC: 2-input NAND gate
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
AD5622ACPZ-2-RL7printed D16 pins, Analog DevicesNot recorded6 pinsAnalog Devices
Printed D1 on the part. Easy to misread as QI-. Check that character with a loupe before you order anything.
- 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.
AD8317ACPZ-WPprinted Q18 pins, Analog DevicesNot recorded8 pinsAnalog Devices
Printed Q1 on the part. Easy to misread as QI-. Check that character with a loupe before you order anything.
- What it is
- Not recorded
- Maker
- Analog Devices
- Package
- Not recorded
- Pins
- 8
- Source
- Published code list
Is it dead? The meter test is below: This part.
ADA4310-1ARHZprinted 0L10 pins, Analog DevicesNot recorded10 pinsAnalog Devices
Printed 0L on the part. Easy to misread as QI-. Check that character with a loupe before you order anything.
- What it is
- Not recorded
- Maker
- Analog Devices
- Package
- Not recorded
- Pins
- 10
- Source
- Published code list
Is it dead? The meter test is below: This part.
AP131-23TWprinted DIAnachipNot recordedNot recordedAnachip
Printed DI on the part. Easy to misread as QI-. Check that character with a loupe before you order anything.
- What it is
- Not recorded
- Maker
- Anachip
- Package
- Not recorded
- Pins
- Not recorded
- Details
- VR-IC: LDO, CE, 2,3V±2%, 300mA
- Source
- Published code list
Is it dead? The meter test is below: Voltage regulator.
AP131-26TWprinted DLAnachipNot recordedNot recordedAnachip
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
- Anachip
- Package
- Not recorded
- Pins
- Not recorded
- Details
- VR-IC: LDO, CE, 2,6V±2%, 300mA
- Source
- Published code list
Is it dead? The meter test is below: Voltage regulator.
AP131-42TWprinted D1AnachipNot recordedNot recordedAnachip
Printed D1 on the part. Easy to misread as QI-. Check that character with a loupe before you order anything.
- What it is
- Not recorded
- Maker
- Anachip
- Package
- Not recorded
- Pins
- Not recorded
- Details
- VR-IC: LDO, CE, 4,2V±2%, 300mA
- Source
- Published code list
Is it dead? The meter test is below: Voltage regulator.
AP8821C-31GIprinted D1Voltage supervisor, Anwell SemiconductorVoltage supervisorNot recordedAnwell 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
- Not recorded
- Pins
- Not recorded
- 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-31GSprinted D1Voltage supervisor, Anwell SemiconductorVoltage supervisorNot recordedAnwell 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
- Not recorded
- Pins
- Not recorded
- 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-31PIprinted D1Voltage supervisor, Anwell SemiconductorVoltage supervisorNot recordedAnwell 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
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 3.1V±2%, -Reset PPO
- 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.
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.
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.
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.
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