SMD code A1t
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 A1 was searched.
209 parts are printed A1t
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.
1N4001WSOD-123FRectifier, 2 pins, Blue RocketRectifierSOD-123F2 pinsBlue Rocket
- What it is
- Rectifier
- Maker
- Blue Rocket
- Package
- SOD-123F
- Pins
- 2
- Details
- Rectifier diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
1N4148TGSOD-723Switching diode, 2 pins, YFWSwitching diodeSOD-7232 pinsYFW
- What it is
- Switching diode
- Maker
- YFW
- Package
- SOD-723
- Pins
- 2
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
1SS181SOT-23Switching diode, 3 pins, Formosa MicrosemiSwitching diodeSOT-233 pinsFormosa Microsemi
- What it is
- Switching diode
- Maker
- Formosa Microsemi
- Package
- SOT-23
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
ABAW56-HFSOT-23Switching diode, 3 pins, ComchipSwitching diodeSOT-233 pinsComchip
- What it is
- Switching diode
- Maker
- Comchip
- Package
- SOT-23
- Pins
- 3
- Details
- 75 V, 150 mA switching diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
ACGRTS4001-HFSOD-123FRectifier, 2 pins, ComchipRectifierSOD-123F2 pinsComchip
- What it is
- Rectifier
- Maker
- Comchip
- Package
- SOD-123F
- Pins
- 2
- Details
- 50 V, 1 A rectifier
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
AO3401SOT-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.
AO3401LSOT-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.
BAP64QSOT-23-5PIN diode, 5 pins, NXPPIN diodeSOT-23-55 pinsNXP
- What it is
- PIN diode
- Maker
- NXP
- Package
- SOT-23-5
- Pins
- 5
- Details
- 1 Product profile
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: PIN diode or varicap.
BAS16HSOD-123FSwitching diode, 2 pins, NexperiaSwitching diodeSOD-123F2 pinsNexperia
- What it is
- Switching diode
- Maker
- Nexperia
- Package
- SOD-123F
- Pins
- 2
- Pinout
- 1 cathode
- 2 anode
- Details
- 0.2A, 75V, Surface Mount Small Signal Switching Diodes
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
BAW56SOT-23Switching diode, 3 pins, InfineonSwitching diodeSOT-233 pinsInfineon
- What it is
- Switching diode
- Maker
- Infineon
- Package
- SOT-23
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
BAW56-CSOT-23Switching diode, 3 pins, SeCoSSwitching diodeSOT-233 pinsSeCoS
- What it is
- Switching diode
- Maker
- SeCoS
- Package
- SOT-23
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
BAW56-HFSOT-23Switching diode, 3 pins, ComchipSwitching diodeSOT-233 pinsComchip
- What it is
- Switching diode
- Maker
- Comchip
- Package
- SOT-23
- Pins
- 3
- Details
- 70 V, 200 mA switching diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
BAW56-P2-HFSOT-23Switching diode, 3 pins, ComchipSwitching diodeSOT-233 pinsComchip
- What it is
- Switching diode
- Maker
- Comchip
- Package
- SOT-23
- Pins
- 3
- Details
- 75 V, 250 mA switching diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
BAW56,215SOT-23Switching diode, 3 pins, HXYSwitching diodeSOT-233 pinsHXY
- What it is
- Switching diode
- Maker
- HXY
- Package
- SOT-23
- Pins
- 3
- Details
- Switching diode, 70 V, 0.2 A
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
1 more part has no package on record
BAV222Switching diode, InfineonSwitching diodeNot recordedNot 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.
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.
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.
PIN diode or varicap
Diode range, part lifted or one leg off the pad. Red probe on the anode.
Working, it reads
About 0.6 to 0.9 V anode to cathode, and open the other way.
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.
- 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 varicap that has drifted in capacitance reads normal on a meter. Only a capacitance meter or the tuning itself shows it.
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 A1t
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.
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