SMD code 431 in SOT-23
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.
11 parts in SOT-23 are printed 431
Not sure which one you have?
Answer up to 4 quick questions and these 19 parts are ranked, with a meter test that settles it. It works on a dead part too.
BL431SOT-23Voltage reference, Galaxy MicroelectronicsVoltage referenceGalaxy Microelectronics
- What it is
- Voltage reference
- Maker
- Galaxy Microelectronics
- Package
- SOT-23
- Pins
- 3
- Details
- 2.5 V Voltage Reference
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
BL431-3LSOT-23Voltage reference, Galaxy MicroelectronicsVoltage referenceGalaxy Microelectronics
- What it is
- Voltage reference
- Maker
- Galaxy Microelectronics
- Package
- SOT-23
- Pins
- 3
- Details
- 2.5 V Voltage Reference
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
BL431-ASOT-23Voltage reference, Galaxy MicroelectronicsVoltage referenceGalaxy Microelectronics
- What it is
- Voltage reference
- Maker
- Galaxy Microelectronics
- Package
- SOT-23
- Pins
- 3
- Details
- 2.5 V Voltage Reference
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
GS431-TRSOT-23Voltage reference, GainsilVoltage referenceGainsil
- What it is
- Voltage reference
- Maker
- Gainsil
- Package
- SOT-23
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
TL431SOT-23Voltage reference, HXYVoltage referenceHXY
- What it is
- Voltage reference
- Maker
- HXY
- Package
- SOT-23
- Pins
- 3
- Details
- Voltage reference, 0.1 A
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
TL431A-CSOT-23Voltage reference, SeCoSVoltage referenceSeCoS
- What it is
- Voltage reference
- Maker
- SeCoS
- Package
- SOT-23
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
TL431ASFSOT-23Voltage reference, HTC KoreaVoltage referenceHTC Korea
- What it is
- Voltage reference
- Maker
- HTC Korea
- Package
- SOT-23
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
TL431BSOT-23Voltage reference, SeCoSVoltage referenceSeCoS
- What it is
- Voltage reference
- Maker
- SeCoS
- Package
- SOT-23
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
TL431N3SOT-23Voltage reference, CYStekVoltage referenceCYStek
- What it is
- Voltage reference
- Maker
- CYStek
- Package
- SOT-23
- Pins
- 3
- Details
- Adjustable shunt regulator, 2.495(Ref.) V reference
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
PZM4.3NB1SOT-23NexperiaNot recordedNexperia
- What it is
- Not recorded
- Maker
- Nexperia
- Package
- SOT-23
- Pins
- 3
- Details
- 4.3V 0.3W zener
- Source
- Published code list
Is it dead? The meter test is below: Zener diode.
TL431KSOT-23UnisonicNot recordedUnisonic
- What it is
- Not recorded
- Maker
- Unisonic
- Package
- SOT-23
- Pins
- 3
- Details
- Shunt reference
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
4 more parts have no package on record. Nothing rules them out, so they stay.
ET431BETEKNot recordedETEK
- What it is
- Not recorded
- Maker
- ETEK
- Package
- Not recorded
- Pins
- Not recorded
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: This part.
TL431CFVoltage reference, HTC KoreaVoltage referenceHTC Korea
- What it is
- Voltage reference
- Maker
- HTC Korea
- Package
- Not recorded
- Pins
- Not recorded
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
TL431CSFVoltage reference, HTC KoreaVoltage referenceHTC Korea
- What it is
- Voltage reference
- Maker
- HTC Korea
- Package
- Not recorded
- Pins
- Not recorded
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
TL431FVoltage reference, HTC KoreaVoltage referenceHTC Korea
- What it is
- Voltage reference
- Maker
- HTC Korea
- Package
- Not recorded
- Pins
- Not recorded
- Source
- Manufacturer 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.
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.
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.
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.
Printed with a code easy to misread as 431
One character differs, and it is one that is easy to confuse under a lamp. Each code has a page of its own.
Codes that begin with 431
For a marking with its end worn or burnt off. Each code has a page of its own.
Codes not listed here are printed on 1 more part.
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