SMD code A4p
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, p, is lower case, which on NXP and Philips parts is a date or factory code, so it was set aside and A4 was searched.
243 parts are printed A4p
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.
BAV70HSOT-23Switching diode, 3 pins, Taiwan SemiconductorSwitching diodeSOT-233 pinsTaiwan Semiconductor
- What it is
- Switching diode
- Maker
- Taiwan Semiconductor
- Package
- SOT-23
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
BAV70LSOT-23Switching diode, 3 pins, onsemiSwitching diodeSOT-233 pinsonsemi
- What it is
- Switching diode
- Maker
- onsemi
- Package
- SOT-23
- Pins
- 3
- Details
- Small Signal Fast Switching Diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
BAV70MSOT-723Switching diode, 3 pins, Galaxy MicroelectronicsSwitching diodeSOT-7233 pinsGalaxy Microelectronics
- What it is
- Switching diode
- Maker
- Galaxy Microelectronics
- Package
- SOT-723
- Pins
- 3
- Details
- 0.15A, 75V, Surface Mount Small Signal Switching Diodes
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
BAV70SSOT-363Switching diode, 6 pins, NexperiaSwitching diodeSOT-3636 pinsNexperia
- What it is
- Switching diode
- Maker
- Nexperia
- Package
- SOT-363
- Pins
- 6
- Details
- High-speed switching diode, quadruple common cathode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
BAV70TSOT-416Switching diode, 3 pins, NexperiaSwitching diodeSOT-4163 pinsNexperia
- What it is
- Switching diode
- Maker
- Nexperia
- Package
- SOT-416
- Pins
- 3
- Details
- 0.15A, 75V, Surface Mount Small Signal Switching Diodes
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
BAV70WSOT-323Switching diode, 3 pins, HXYSwitching diodeSOT-3233 pinsHXY
- What it is
- Switching diode
- Maker
- HXY
- Package
- SOT-323
- Pins
- 3
- Details
- SMD Small Signal Diodes
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
BAV70W-CSOT-323Switching diode, 3 pins, SeCoSSwitching diodeSOT-3233 pinsSeCoS
- What it is
- Switching diode
- Maker
- SeCoS
- Package
- SOT-323
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
BZT52B2V0SOD-123Zener diode, 2 pins, YFWZener diodeSOD-1232 pinsYFW
- What it is
- Zener diode
- Maker
- YFW
- Package
- SOD-123
- Pins
- 2
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
CGRM4004-HFSOD-123FRectifier, 2 pins, ComchipRectifierSOD-123F2 pinsComchip
- What it is
- Rectifier
- Maker
- Comchip
- Package
- SOD-123F
- Pins
- 2
- Details
- 400 V, 1 A rectifier
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
CGRMT4004-HFSOD-123FRectifier, 2 pins, ComchipRectifierSOD-123F2 pinsComchip
- What it is
- Rectifier
- Maker
- Comchip
- Package
- SOD-123F
- Pins
- 2
- Details
- 400 V, 1 A rectifier
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
CGRTS4004-HFSOD-123FRectifier, 2 pins, ComchipRectifierSOD-123F2 pinsComchip
- What it is
- Rectifier
- Maker
- Comchip
- Package
- SOD-123F
- Pins
- 2
- Details
- 400 V, 1 A rectifier
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
CHEMA4GPSOT-553Digital transistor (PNP, resistors built in), 5 pins, ChenmkoDigital transistor (PNP, resistors built in)SOT-5535 pinsChenmko
- What it is
- Digital transistor (PNP, resistors built in)
- Maker
- Chenmko
- Package
- SOT-553
- Pins
- 5
- Details
- Dual Digital Silicon Transistor, 50 V, 100 mA
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Digital transistor.
CHN202KGPSOT-23Switching diode, 3 pins, ChenmkoSwitching diodeSOT-233 pinsChenmko
- What it is
- Switching diode
- Maker
- Chenmko
- Package
- SOT-23
- Pins
- 3
- Details
- SWITCHING DIODE, 80 V, 0.1 A
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
CHN222GPSOT-416Switching diode, 3 pins, ChenmkoSwitching diodeSOT-4163 pinsChenmko
- What it is
- Switching diode
- Maker
- Chenmko
- Package
- SOT-416
- Pins
- 3
- Details
- SWITCHING DIODE, 80 V, 0.1 A
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
1 more part has no package on record
BZX884B3V3Zener 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 3.3 V, 0.25 W
- 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.
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.
Did you find your part?
Open this in the search to correct a character or try another package.