SMD code ALs
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, s, is lower case, which on NXP and Philips parts is a date or factory code, so it was set aside and AL was searched.
154 parts are printed ALs
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.
1N4151WSOD-123Switching diode, 2 pins, VishaySwitching diodeSOD-1232 pinsVishay
- What it is
- Switching diode
- Maker
- Vishay
- Package
- SOD-123
- Pins
- 2
- Details
- SMD Switching Diodes (Two Terminals)
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
1N4151W-GSOD-123Switching diode, 2 pins, VishaySwitching diodeSOD-1232 pinsVishay
- What it is
- Switching diode
- Maker
- Vishay
- Package
- SOD-123
- Pins
- 2
- Details
- Small Signal Fast Switching Diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
ABCX53-16-HFSOT-89PNP transistor, 3 pins, ComchipPNP transistorSOT-893 pinsComchip
- What it is
- PNP transistor
- Maker
- Comchip
- Package
- SOT-89
- Pins
- 3
- Details
- -80 V, -1 A PNP transistor
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: PNP transistor.
AO3419SOT-23P-channel MOSFET, 3 pins, Alpha & Omega SemiconductorP-channel MOSFETSOT-233 pinsAlpha & Omega Semiconductor
- What it is
- P-channel MOSFET
- Maker
- Alpha & Omega Semiconductor
- Package
- SOT-23
- Pins
- 3
- Details
- P-channel MOSFET (8-60 V)
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: P-channel MOSFET.
AO3419LSOT-23P-channel MOSFET, 3 pins, Alpha & Omega SemiconductorP-channel MOSFETSOT-233 pinsAlpha & Omega Semiconductor
- What it is
- P-channel MOSFET
- Maker
- Alpha & Omega Semiconductor
- Package
- SOT-23
- Pins
- 3
- Details
- P-channel MOSFET (8-60 V)
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: P-channel MOSFET.
BAV70M3SOT-723Switching diode, 3 pins, onsemiSwitching diodeSOT-7233 pinsonsemi
- What it is
- Switching diode
- Maker
- onsemi
- Package
- SOT-723
- Pins
- 3
- Details
- Dual Switching Diode Common Cathode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
BCP53-16SOT-223PNP transistor, 4 pins, Galaxy MicroelectronicsPNP transistorSOT-2234 pinsGalaxy Microelectronics
- What it is
- PNP transistor
- Maker
- Galaxy Microelectronics
- Package
- SOT-223
- Pins
- 4
- Details
- -80V, -1A, General Purpose PNP Bipolar Transistor
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: PNP transistor.
BCX53-16SOT-89Transistor, 3 pins, InfineonTransistorSOT-893 pinsInfineon
- What it is
- Transistor
- Maker
- Infineon
- Package
- SOT-89
- Pins
- 3
- Details
- SMD General Purpose PNP Transistors
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Bipolar transistor.
BCX53-16-Q1SOT-89PNP transistor, 3 pins, Formosa MicrosemiPNP transistorSOT-893 pinsFormosa Microsemi
- What it is
- PNP transistor
- Maker
- Formosa Microsemi
- Package
- SOT-89
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: PNP transistor.
BCX53-16,115SOT-89PNP transistor, 3 pins, HXYPNP transistorSOT-893 pinsHXY
- What it is
- PNP transistor
- Maker
- HXY
- Package
- SOT-89
- Pins
- 3
- Details
- Bipolar transistor, 80 V, 1 A
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: PNP transistor.
BFP405SOT-343RF transistor, 4 pins, InfineonRF transistorSOT-3434 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.
4 more parts have no package on record
AOZ8300CI-03ESD protection diode, Alpha & Omega SemiconductorESD protection diodeNot recordedNot recordedAlpha & Omega Semiconductor
- What it is
- ESD protection diode
- Maker
- Alpha & Omega Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- ESD protection for high-speed interfaces
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
BZX884B5V1LZener diode, VishayZener diodeNot recordedNot recordedVishay
- What it is
- Zener diode
- Maker
- Vishay
- Package
- Not recorded
- Pins
- Not recorded
- Details
- 5.1 V Zener diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
BZX884B15Zener diode, Good-ArkZener diodeNot recordedNot recordedGood-Ark
- What it is
- Zener diode
- Maker
- Good-Ark
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Zener diode, VZ 15 V, 0.25 W
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
BZX884B15VZener diode, RectronZener diodeNot recordedNot recordedRectron
- What it is
- Zener diode
- Maker
- Rectron
- Package
- Not recorded
- Pins
- Not recorded
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener 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.
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.
PNP transistor
Diode range, part lifted or its base leg off the pad.
Working, it reads
Black 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.
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.
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.
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.
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 ALs
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 31 more parts.
Did you find your part?
Open this in the search to correct a character or try another package.