SMD code A4
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.
11 parts are printed A4
Not sure which one you have?
Answer up to 4 quick questions and these 11 parts are ranked, with a meter test that settles it. It works on a dead part too.
BAT760SOD-323Schottky diode, 2 pins, NexperiaSchottky diodeSOD-3232 pinsNexperia
- What it is
- Schottky diode
- Maker
- Nexperia
- Package
- SOD-323
- Pins
- 2
- Details
- Medium power Schottky barrier single diode
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: Schottky diode.
BAV70SOT-23Switching diode, 3 pins, DiotecSwitching diodeSOT-233 pinsDiotec
- What it is
- Switching diode
- Maker
- Diotec
- Package
- SOT-23
- Pins
- 3
- Details
- Dual surface-mount switching diode, common cathode
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: Silicon diode.
BAV70DWSOT-363Switching diode, 6 pins, DiotecSwitching diodeSOT-3636 pinsDiotec
- What it is
- Switching diode
- Maker
- Diotec
- Package
- SOT-363
- Pins
- 6
- Details
- SMD Small Signal Diode Arrays
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: Silicon diode.
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
- From the manufacturer's 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
- From the manufacturer's 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
- High-speed switching diode, dual common cathode
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: Silicon diode.
BAV70WSOT-323Switching diode, 3 pins, NexperiaSwitching diodeSOT-3233 pinsNexperia
- What it is
- Switching diode
- Maker
- Nexperia
- Package
- SOT-323
- Pins
- 3
- Details
- SMD Small Signal Diodes
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: Silicon diode.
MMBD4148CCSOT-23Switching diode, 3 pins, Taiwan SemiconductorSwitching diodeSOT-233 pinsTaiwan Semiconductor
- What it is
- Switching diode
- Maker
- Taiwan Semiconductor
- Package
- SOT-23
- Pins
- 3
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: Silicon diode.
PMEG3005EHSOD-123FSchottky diode, 2 pins, NexperiaSchottky diodeSOD-123F2 pinsNexperia
- What it is
- Schottky diode
- Maker
- Nexperia
- Package
- SOD-123F
- Pins
- 2
- Details
- 30 V, 0.5 A very low VF MEGA Schottky barrier rectifier
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: Schottky diode.
SN74AUP1G00DPWX2SONLogic gate, 5 pins, Texas InstrumentsLogic gateX2SON5 pinsTexas Instruments
- What it is
- Logic gate
- Maker
- Texas Instruments
- Package
- X2SON
- Pins
- 5
- Details
- Low-Power Single 2-Input Positive-NAND Gate
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: Integrated circuit.
TPS3831G12DQNX2SONVoltage supervisor, 4 pins, Texas InstrumentsVoltage supervisorX2SON4 pinsTexas Instruments
- What it is
- Voltage supervisor
- Maker
- Texas Instruments
- Package
- X2SON
- Pins
- 4
- Details
- 150-nA, Ultralow Power, Supply Voltage Monitor
- Source
- From the manufacturer's datasheet
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.
Schottky diode
Diode range, part lifted or one leg off the pad. Red probe on the anode.
Working, it reads
About 0.15 to 0.45 V anode to cathode, roughly half a silicon diode, 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.
- A reading the wrong way round as well: leaky.
- 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 large Schottky can read about 0.1 V forward and beep like a short, and leaks a little the wrong way when good, more when warm. It is shorted only if it reads the same both ways. Measure it cold, beside an identical cold one.
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.
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.
Codes that begin with A4
For a marking with its end worn or burnt off. Each code has a page of its own.
Open this in the search to correct a character or try another package.