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SMD code FY in DFN

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.

Not sure which one you have?

Answer up to 4 quick questions and these 26 parts are ranked, with a meter test that settles it. It works on a dead part too.

  • R3114K291CDFNVoltage supervisor, RicohVoltage supervisorRicoh
    What it is
    Voltage supervisor
    Maker
    Ricoh
    Package
    DFN
    Pins
    Not recorded
    Details
    Voltage detector IC: 2.9V±0.8%, -Reset PPO
    Source
    Published code list

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

  • R3134K31ECDFNVoltage supervisor, RicohVoltage supervisorRicoh
    What it is
    Voltage supervisor
    Maker
    Ricoh
    Package
    DFN
    Pins
    Not recorded
    Details
    Voltage detector IC: 3.1V±1.8%, -Reset PPO, -MR
    Source
    Published code list

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

  • 13 more parts have no package on record. Nothing rules them out, so they stay.
    • MM5Z3V6BZener diode, Formosa MicrosemiZener diodeFormosa Microsemi
      What it is
      Zener diode
      Maker
      Formosa Microsemi
      Package
      Not recorded
      Pins
      Not recorded
      Source
      Manufacturer datasheet

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

    • MM5Z3V6B-Q1Zener diode, Formosa MicrosemiZener diodeFormosa Microsemi
      What it is
      Zener diode
      Maker
      Formosa Microsemi
      Package
      Not recorded
      Pins
      Not recorded
      Source
      Manufacturer datasheet

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

    • RQ5L030ATP-channel MOSFET, ROHMP-channel MOSFETROHM
      What it is
      P-channel MOSFET
      Maker
      ROHM
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Pch -60V -3.0A Small Signal MOSFET
      Source
      Manufacturer datasheet

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

    • BD48L30GVoltage supervisor, ROHMVoltage supervisorROHM
      What it is
      Voltage supervisor
      Maker
      ROHM
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage Detector
      Source
      Published code list

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

    • BU45L262GVoltage supervisor, ROHMVoltage supervisorROHM
      What it is
      Voltage supervisor
      Maker
      ROHM
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage detector IC: 2.6V±1%, -Reset ODO, Rdt=200ms
      Source
      Published code list

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

    • FSA2156FHXFairchild SemiconductorNot recordedFairchild Semiconductor
      What it is
      Not recorded
      Maker
      Fairchild Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      CMOS logic IC: Single-pole/single-throw analog switch
      Source
      Published code list

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

    • FSA2156P6XFairchild SemiconductorNot recordedFairchild Semiconductor
      What it is
      Not recorded
      Maker
      Fairchild Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      CMOS logic IC: Single-pole/single-throw analog switch
      Source
      Published code list

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

    • IXD5127C52ANRVoltage supervisor, IXYSVoltage supervisorIXYS
      What it is
      Voltage supervisor
      Maker
      IXYS
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage detector IC: 5.2V±0.8%, -Reset PPO, -MR, 50ms Rt delay
      Source
      Published code list

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

    • IXD5127N52FNRVoltage supervisor, IXYSVoltage supervisorIXYS
      What it is
      Voltage supervisor
      Maker
      IXYS
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage detector IC: 5.2V±0.8%, +Reset ODO, -MR, 50ms Rt delay
      Source
      Published code list

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

    • KDZ3.3VVYZener diode, KECZener diodeKEC
      What it is
      Zener diode
      Maker
      KEC
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Zener diode: 3.25..3.50V, Izt=5mA, Zzt=130, 100mW
      Source
      Published code list

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

    • KTA2013F-YPNP transistor, KECPNP transistorKEC
      What it is
      PNP transistor
      Maker
      KEC
      Package
      Not recorded
      Pins
      Not recorded
      Details
      PNP transistor: AF, Sw, 20V, 150mA, 50mW, B=120..240, >80MHz
      Source
      Published code list

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

    • RP300K28DCVoltage supervisor, RicohVoltage supervisorRicoh
      What it is
      Voltage supervisor
      Maker
      Ricoh
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage detector IC: 2.8V±1%, +Reset PPO, -MR, Rdt=200ms
      Source
      Published code list

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

    • XC6127C52ANRVoltage supervisor, TorexVoltage supervisorTorex
      What it is
      Voltage supervisor
      Maker
      Torex
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Voltage detector IC: 5.2V±0.8%, -Reset PPO, -MR, Rdt=50ms
      Source
      Published code list

      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.

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.

PNP transistor

Diode range, part lifted or its base leg off the pad.

Working, it reads

Black probe on the base reads about 0.6 to 0.75 V to the emitter and to the collector, and open the other way round. Collector to emitter reads open both ways.

Dead, it reads

  • Collector to emitter the same both ways, near 0 V with a continuous beep: shorted. The commonest failure.
  • The base the same both ways to another pin, near 0 V or a middling value: a shorted junction.
  • Only one junction reads, or none: a junction has failed open. It then looks like a diode.
  • A reading the wrong way round, where it should be open: 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 pair of diodes with a common pin reads just like a transistor, and some transistors carry a built-in diode or resistor. The datasheet says which.

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 FY

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 7 more parts.

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