SMD code A1 in SOT-89
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.
5 parts in SOT-89 are printed A1
Not sure which one you have?
Answer up to 4 quick questions and these 49 parts are ranked, with a meter test that settles it. It works on a dead part too.
D70G.05T1SOT-893 pins, GenNot recorded3 pinsGen
- What it is
- Not recorded
- Maker
- Gen
- Package
- SOT-89
- Pins
- 3
- Details
- Si-npn: Sw, 200/150V, 50mA
- Source
- Published code list
Is it dead? The meter test is below: This part.
ELM9821ABSOT-893 pins, ELM TechnologyNot recorded3 pinsELM Technology
- What it is
- Not recorded
- Maker
- ELM Technology
- Package
- SOT-89
- Pins
- 3
- Details
- Linear voltage regulator IC: 2.1V±2%, 200mA
- Source
- Published code list
Is it dead? The meter test is below: Voltage regulator.
ELM89211ASOT-89LDO regulator, 3 pins, ELM TechnologyLDO regulator3 pinsELM Technology
- What it is
- LDO regulator
- Maker
- ELM Technology
- Package
- SOT-89
- Pins
- 3
- Details
- Linear voltage regulator IC: LDO, 2.1V±2%, 300mA
- Source
- Published code list
Is it dead? The meter test is below: Voltage regulator.
RT9162-35CXSOT-89LDO regulator, 3 pins, RichtekLDO regulator3 pinsRichtek
- What it is
- LDO regulator
- Maker
- Richtek
- Package
- SOT-89
- Pins
- 3
- Details
- Linear voltage regulator IC: LDO, 3.5V±2%, 300mA
- Source
- Published code list
Is it dead? The meter test is below: Voltage regulator.
S-80737AL-A1SOT-893 pins, ABLICNot recorded3 pinsABLIC
- What it is
- Not recorded
- Maker
- ABLIC
- Package
- SOT-89
- Pins
- 3
- Details
- equivalent S-80737AL
- Source
- Published code list
Is it dead? The meter test is below: This part.
10 more parts have no package on record. Nothing rules them out, so they stay.
BAV222Switching diode, InfineonSwitching diodeNot recordedInfineon
- What it is
- Switching diode
- Maker
- Infineon
- Package
- Not recorded
- Pins
- Not recorded
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
BAW222Diode, InfineonDiodeNot recordedInfineon
- What it is
- Diode
- Maker
- Infineon
- Package
- Not recorded
- Pins
- Not recorded
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
BZX884B2V4Zener diode, Good-ArkZener diodeNot recordedGood-Ark
- What it is
- Zener diode
- Maker
- Good-Ark
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Zener diode, VZ 2.4 V, 0.25 W
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
FM4001-LRectifier, Formosa MicrosemiRectifierNot recordedFormosa Microsemi
- What it is
- Rectifier
- Maker
- Formosa Microsemi
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Rectifier diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
FM4001-L-Q1Rectifier, Formosa MicrosemiRectifierNot recordedFormosa Microsemi
- What it is
- Rectifier
- Maker
- Formosa Microsemi
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Rectifier diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
FM4001-MHRectifier, Formosa MicrosemiRectifierNot recordedFormosa Microsemi
- What it is
- Rectifier
- Maker
- Formosa Microsemi
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Rectifier diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
FM4001-MH-Q1Rectifier, Formosa MicrosemiRectifierNot recordedFormosa Microsemi
- What it is
- Rectifier
- Maker
- Formosa Microsemi
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Rectifier diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
FM4001-MSRectifier, Formosa MicrosemiRectifierNot recordedFormosa Microsemi
- What it is
- Rectifier
- Maker
- Formosa Microsemi
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Rectifier diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
FM4001-MS-Q1Rectifier, Formosa MicrosemiRectifierNot recordedFormosa Microsemi
- What it is
- Rectifier
- Maker
- Formosa Microsemi
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Rectifier diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
FM4001-MSTRectifier, Formosa MicrosemiRectifierNot recordedFormosa Microsemi
- What it is
- Rectifier
- Maker
- Formosa Microsemi
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Rectifier diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon 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.
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.
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.
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.
Printed with a code easy to misread as A1
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 9 more parts.
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