Skip to content

SMD code POs 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 PO was searched.

2 parts in SOT-323 are printed POs

Not sure which one you have?

Answer up to 4 quick questions and these 13 parts are ranked, with a meter test that settles it. It works on a dead part too.

  • KRA313SOT-323Digital transistor (PNP, resistors built in), 3 pins, KECDigital transistor (PNP, resistors built in)3 pinsKEC
    What it is
    Digital transistor (PNP, resistors built in)
    Maker
    KEC
    Package
    SOT-323
    Pins
    3
    Source
    Manufacturer datasheet

    Is it dead? The meter test is below: Digital transistor.

  • BAR64-04WSOT-323PIN diode, 3 pins, InfineonPIN diode3 pinsInfineon
    What it is
    PIN diode
    Maker
    Infineon
    Package
    SOT-323
    Pins
    3
    Details
    dual series 200V RF pin
    Source
    Published code list

    Is it dead? The meter test is below: PIN diode or varicap.

  • 11 more parts have no package on record. Nothing rules them out, so they stay.
    • KRA313EDigital transistor (PNP, resistors built in), KECDigital transistor (PNP, resistors built in)Not recordedKEC
      What it is
      Digital transistor (PNP, resistors built in)
      Maker
      KEC
      Package
      Not recorded
      Pins
      Not recorded
      Source
      Manufacturer datasheet

      Is it dead? The meter test is below: Digital transistor.

    • KRA313VDigital transistor (PNP, resistors built in), KECDigital transistor (PNP, resistors built in)Not recordedKEC
      What it is
      Digital transistor (PNP, resistors built in)
      Maker
      KEC
      Package
      Not recorded
      Pins
      Not recorded
      Source
      Manufacturer datasheet

      Is it dead? The meter test is below: Digital transistor.

    • KRA563EDigital transistor (PNP, resistors built in), KECDigital transistor (PNP, resistors built in)Not recordedKEC
      What it is
      Digital transistor (PNP, resistors built in)
      Maker
      KEC
      Package
      Not recorded
      Pins
      Not recorded
      Source
      Manufacturer datasheet

      Is it dead? The meter test is below: Digital transistor.

    • KRA563UDigital transistor (PNP, resistors built in), KECDigital transistor (PNP, resistors built in)Not recordedKEC
      What it is
      Digital transistor (PNP, resistors built in)
      Maker
      KEC
      Package
      Not recorded
      Pins
      Not recorded
      Source
      Manufacturer datasheet

      Is it dead? The meter test is below: Digital transistor.

    • KRA763EDigital transistor (PNP, resistors built in), KECDigital transistor (PNP, resistors built in)Not recordedKEC
      What it is
      Digital transistor (PNP, resistors built in)
      Maker
      KEC
      Package
      Not recorded
      Pins
      Not recorded
      Source
      Manufacturer datasheet

      Is it dead? The meter test is below: Digital transistor.

    • KRA763UDigital transistor (PNP, resistors built in), KECDigital transistor (PNP, resistors built in)Not recordedKEC
      What it is
      Digital transistor (PNP, resistors built in)
      Maker
      KEC
      Package
      Not recorded
      Pins
      Not recorded
      Source
      Manufacturer datasheet

      Is it dead? The meter test is below: Digital transistor.

    • AX6645WCTLDO regulator, AXElite TechnologyLDO regulatorNot recordedAXElite Technology
      What it is
      LDO regulator
      Maker
      AXElite Technology
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Linear voltage regulator IC: LDO, Dual out., Vo1/Vo2=1.2V/2.8V±2%, 200mA, +CE
      Source
      Published code list

      Is it dead? The meter test is below: Voltage regulator.

    • S-1132B33-A6T16 pins, ABLICNot recorded6 pinsABLIC
      What it is
      Not recorded
      Maker
      ABLIC
      Package
      Not recorded
      Pins
      6
      Details
      equivalent [3.3V LDO]
      Source
      Published code list

      Is it dead? The meter test is below: Voltage regulator.

    • S-1132B33-I6T26 pins, ABLICNot recorded6 pinsABLIC
      What it is
      Not recorded
      Maker
      ABLIC
      Package
      Not recorded
      Pins
      6
      Details
      equivalent [3.3V LDO]
      Source
      Published code list

      Is it dead? The meter test is below: Voltage regulator.

    • S-1200B33-A6T1SLDO regulator, Seiko InstrumentsLDO regulatorNot recordedSeiko Instruments
      What it is
      LDO regulator
      Maker
      Seiko Instruments
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Linear voltage regulator IC: LDO, 3.3V±1.0%, 150mA, +CE
      Source
      Published code list

      Is it dead? The meter test is below: Voltage regulator.

    • S-1200B33-I6T2GLDO regulator, Seiko InstrumentsLDO regulatorNot recordedSeiko Instruments
      What it is
      LDO regulator
      Maker
      Seiko Instruments
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Linear voltage regulator IC: LDO, 3.3V±1.0%, 150mA, +CE
      Source
      Published code list

      Is it dead? The meter test is below: Voltage regulator.

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.

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.

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.

Voltage regulator

Voltage, board powered, black probe on ground. Then ohms with the power off.

Working, it reads

Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.

Dead, it reads

  • Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
  • Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
  • Power off, input to output near 0 Ω: shorted.
On the board:
An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
Compare:
The same regulator on another rail or another board shows the right voltages and the right resistances.
Watch for:
Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.

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 POs

One character differs, and it is one that is easy to confuse under a lamp. Each code has a page of its own.

Did you find your part?

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