Skip to content
WhatSMDSign in

SMD code U72 in SOT-343

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.

3 parts in SOT-343 are printed U72

Not sure which one you have?

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

  • 2SK299U72SOT-343RenesasRenesas
    What it is
    Not recorded
    Maker
    Renesas
    Package
    SOT-343
    Pins
    4
    Source
    Published code list

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

  • 3SK299SOT-343RenesasRenesas
    What it is
    Not recorded
    Maker
    Renesas
    Package
    SOT-343
    Pins
    4
    Details
    dg GaAsfet Idss 5-15mA
    Source
    Published code list

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

  • 3SK299-72SOT-343NEC ElectronicsNEC Electronics
    What it is
    N-channel MOSFET
    Maker
    NEC Electronics
    Package
    SOT-343
    Pins
    4
    Details
    MOSFET n-type: GaAs, Dual gate, UHF, 13V, Idss=10..25mA
    Source
    Published code list

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

  • 1 more part has no package on record. Nothing rules it out, so it stays.
    • 3SK177-72NEC ElectronicsNEC Electronics
      What it is
      Not recorded
      Maker
      NEC Electronics
      Package
      Not recorded
      Pins
      Not recorded
      Details
      MESFET n-type: GaAs, Dual gate, UHF, 13V, 40mA, 200mW, Idss=10..25mA
      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.

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.

N-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 source, black on the drain: 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. A drain short can be the load. 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.

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.

Did you find your part?

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