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SMD code BP

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.

9 parts are printed BP

Not sure which one you have?

Answer up to 4 quick questions and these 9 parts are ranked, with a meter test that settles it. It works on a dead part too.

  • AO3451SOT-23P-channel MOSFET, 3 pins, Alpha & Omega Semiconductor
    What it is
    P-channel MOSFET
    Maker
    Alpha & Omega Semiconductor
    Package
    SOT-23
    Pins
    3
    Details
    P-channel MOSFET (8-60 V)
    Source
    From the manufacturer's datasheet

    Is it dead? The meter test is below: P-channel MOSFET.

  • BZT52H-C16SOD-123FZener diode, 2 pins, Nexperia
    What it is
    Zener diode
    Maker
    Nexperia
    Package
    SOD-123F
    Pins
    2
    Source
    From the manufacturer's datasheet

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

  • SMAJ16ASMATVS diode, 2 pins, Vishay
    What it is
    TVS diode
    Maker
    Vishay
    Package
    SMA
    Pins
    2
    Details
    400 W TVS diode, unidirectional
    Source
    From the manufacturer's datasheet

    Is it dead? The meter test is below: TVS or ESD protection diode.

  • SMF16ASOD-123FTVS diode, 2 pins, Vishay
    What it is
    TVS diode
    Maker
    Vishay
    Package
    SOD-123F
    Pins
    2
    Details
    SMD Transient Voltage Suppressor Diodes
    Source
    From the manufacturer's datasheet

    Is it dead? The meter test is below: TVS or ESD protection diode.

  • 5 more parts have no package on record
    • AOZ1331ADILoad switch, Alpha & Omega Semiconductor
      What it is
      Load switch
      Maker
      Alpha & Omega Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Smart load switch
      Source
      From the manufacturer's datasheet

      Is it dead? The meter test is below: Load switch.

    • BGA616RF amplifier (MMIC), Infineon
      What it is
      RF amplifier (MMIC)
      Maker
      Infineon
      Package
      Not recorded
      Pins
      Not recorded
      Source
      From the manufacturer's datasheet

      Is it dead? The meter test is below: RF amplifier.

    • BZX884B56LZener diode, Vishay
      What it is
      Zener diode
      Maker
      Vishay
      Package
      Not recorded
      Pins
      Not recorded
      Details
      56 V Zener diode
      Source
      From the manufacturer's datasheet

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

    • MSMP16ATVS diode, Vishay
      What it is
      TVS diode
      Maker
      Vishay
      Package
      Not recorded
      Pins
      Not recorded
      Details
      150 W TVS diode, unidirectional
      Source
      From the manufacturer's datasheet

      Is it dead? The meter test is below: TVS or ESD protection diode.

    • SMP16ATVS diode, Vishay
      What it is
      TVS diode
      Maker
      Vishay
      Package
      Not recorded
      Pins
      Not recorded
      Details
      400 W TVS diode, unidirectional
      Source
      From the manufacturer's datasheet

      Is it dead? The meter test is below: TVS or ESD protection 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.

P-channel MOSFET

Diode range, part lifted. Test drain to source first, then short gate to source and test again.

Working, it reads

Red probe on the drain, black on the source: about 0.4 to 0.9 V, the body diode. Open the other way. The gate reads open to both other pins, both ways.

Dead, it reads

  • Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
  • The gate reads low to source or drain: gate shorted. Often all three pins end up shorted together.
  • No body diode at all: failed open.
On the board
the gate usually has a resistor to the source, so gate to source reads that resistor, which is not a fault. Lift a leg to be sure.
Compare:
If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
Watch for:
The diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.

A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

Load switch

Voltage, board powered, black probe on ground.

Working, it reads

Switched on, the output pin sits at the input voltage. Switched off, it sits near 0 V.

Dead, it reads

  • Output at the input voltage while switched off: the pass element has shorted.
  • Input present and switched on, no output: failed open, or shut down into a shorted load. Power off and measure output to ground.
On the board:
An output near 0 Ω to ground is usually the load. Lift the output pin to see which.
Compare:
If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
Watch for:
The pinout and whether the enable is active high or low differ between parts. The datasheet gives both.

A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

RF amplifier

Voltage, board powered, on the output pin that the bias resistor or choke feeds.

Working, it reads

The output pin sits at the device voltage the datasheet gives, a few volts, below the supply.

Dead, it reads

  • Output pin at 0 V, or near 0 Ω to ground with the power off: shorted inside.
  • Output pin at the full supply voltage: open inside, no current flowing.
On the board:
Measured on the board with power on; the bias network is part of the reading.
Compare:
If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
Watch for:
The figures depend on the part and its bias resistor. The datasheet gives both.

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.

TVS or ESD protection diode

Diode range, from the protected line to ground, part lifted if you can.

Working, it reads

A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

Dead, it reads

  • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
  • A reading both ways on a one-way part: leaky.
  • A one-way part open both ways: failed open.
On the board
, a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
Compare:
The same part on the next line or connector pin is the healthy reading to compare with.
Watch for:
A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

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 BP

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 BP

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.