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SMD marking

R5Ain SOT-23

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.

2 parts are printed R5A

Not sure which one you have?

Answer up to 4 quick questions and these 2 parts are ranked, with a meter test that settles it. It works on a dead part too.

Voltage reference, all SOT-23, 3 pins, all Texas Instruments.

  • LM4040AIM3-5.0SOT-23
    What it is
    Voltage reference
    Maker
    Texas Instruments
    Package
    SOT-23
    Pins
    3
    Details
    LM4040-N/-Q1 Precision Micropower Shunt Voltage Reference
    Source
    From the manufacturer's datasheet

    Is it dead?

    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.

  • LM4040AIM3X-5.0SOT-23
    What it is
    Voltage reference
    Maker
    Texas Instruments
    Package
    SOT-23
    Pins
    3
    Details
    LM4040-N/-Q1 Precision Micropower Shunt Voltage Reference
    Source
    From the manufacturer's datasheet

    Is it dead?

    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.

3 more parts are printed with a code easy to misread as R5A

Printed with a code easy to misread

One character differs, and it is one that is easy to confuse under a lamp. The odd one out is marked on each.

Voltage reference, all SOT-23, 3 pins, all Texas Instruments.

  • LM4050QAEM3-2.0printed RSASOT-23

    Printed RSA on the part. Easy to misread as R5A. Check that character with a loupe before you order anything.

    What it is
    Voltage reference
    Maker
    Texas Instruments
    Package
    SOT-23
    Pins
    3
    Details
    LM4050-N/-Q1 Precision Micropower Shunt Voltage Reference
    Source
    From the manufacturer's datasheet

    Is it dead?

    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.

  • LM4050QAEM3X2.0printed RSASOT-23

    Printed RSA on the part. Easy to misread as R5A. Check that character with a loupe before you order anything.

    What it is
    Voltage reference
    Maker
    Texas Instruments
    Package
    SOT-23
    Pins
    3
    Details
    LM4050-N/-Q1 Precision Micropower Shunt Voltage Reference
    Source
    From the manufacturer's datasheet

    Is it dead?

    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.

  • LM4050QAIM3-2.0printed RSASOT-23

    Printed RSA on the part. Easy to misread as R5A. Check that character with a loupe before you order anything.

    What it is
    Voltage reference
    Maker
    Texas Instruments
    Package
    SOT-23
    Pins
    3
    Details
    LM4050-N/-Q1 Precision Micropower Shunt Voltage Reference
    Source
    From the manufacturer's datasheet

    Is it dead?

    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.

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