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SMD code W1s in SOT-323

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, s, is lower case, which on NXP and Philips parts is a date or factory code, so it was set aside and W1 was searched.

9 parts in SOT-323 are printed W1s

Not sure which one you have?

Answer up to 4 quick questions and these 22 parts are ranked, with a meter test that settles it. It works on a dead part too.

7 parts have no package on record. Nothing rules them out, so they stay.

  • AP8822C-31PSVoltage supervisor, Anwell SemiconductorVoltage supervisorNot recordedAnwell Semiconductor
    What it is
    Voltage supervisor
    Maker
    Anwell Semiconductor
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Voltage detector IC: 3.1V±2%, -Reset PPO, 200ms Rt delay
    Source
    Published code list

    Is it dead? The meter test is below: Integrated circuit.

  • BD46235GVoltage supervisor, ROHMVoltage supervisorNot recordedROHM
    What it is
    Voltage supervisor
    Maker
    ROHM
    Package
    Not recorded
    Pins
    Not recorded
    Details
    CMOS-IC: Voltage Detector 2,3V, -Reset Push-pull output, 500ms
    Source
    Published code list

    Is it dead? The meter test is below: Integrated circuit.

  • BZT52C2V7LPZener diode, Diodes IncorporatedZener diodeNot recordedDiodes Incorporated
    What it is
    Zener diode
    Maker
    Diodes Incorporated
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Zener diode: 2.5..2.9V, Izt=5mA, Zzt=100, 250mW
    Source
    Published code list

    Is it dead? The meter test is below: Zener diode.

  • EC95810C31C7IVoltage supervisor, E-CMOSVoltage supervisorNot recordedE-CMOS
    What it is
    Voltage supervisor
    Maker
    E-CMOS
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Voltage detector IC: 3.1V±2%, -Reset PPO, Td=200ms
    Source
    Published code list

    Is it dead? The meter test is below: Integrated circuit.

  • EC95810C31C7SVoltage supervisor, E-CMOSVoltage supervisorNot recordedE-CMOS
    What it is
    Voltage supervisor
    Maker
    E-CMOS
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Voltage detector IC: 3.1V±2%, -Reset PPO, Td=200ms
    Source
    Published code list

    Is it dead? The meter test is below: Integrated circuit.

  • HD74LV1GW98ACMRenesasNot recordedNot recordedRenesas
    What it is
    Not recorded
    Maker
    Renesas
    Package
    Not recorded
    Pins
    Not recorded
    Details
    CMOS logic IC: Configurable multiple-function gate
    Source
    Published code list

    Is it dead? The meter test is below: Integrated circuit.

  • PESD3V3V4UW5 pins, NexperiaNot recorded5 pinsNexperia
    What it is
    Not recorded
    Maker
    Nexperia
    Package
    Not recorded
    Pins
    5
    Source
    Published code list

    Is it dead? The meter test is below: This part.

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.

Did you find your part?

Open this in the search to correct a character or try another package.