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SMD code 371B

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.

13 parts are printed 371B

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.

Zener diode, 2 pins. What differs:

  • 1SMC5371BSMCYFWSMCYFW
    What it is
    Zener diode
    Maker
    YFW
    Package
    SMC
    Pins
    2
    Source
    Manufacturer datasheet

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

  • CZRB5371B-HFSMBComchipSMBComchip
    What it is
    Zener diode
    Maker
    Comchip
    Package
    SMB
    Pins
    2
    Details
    60 V 5 mW zener diode
    Source
    Manufacturer datasheet

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

  • CZRC5371B-HFSMCComchipSMCComchip
    What it is
    Zener diode
    Maker
    Comchip
    Package
    SMC
    Pins
    2
    Details
    60 V 5 mW zener diode
    Source
    Manufacturer datasheet

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

  • SMB5371BSMBDOWOSMBDOWO
    What it is
    Zener diode
    Maker
    DOWO
    Package
    SMB
    Pins
    2
    Source
    Manufacturer datasheet

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

  • SMBJ5371BSMBGalaxy MicroelectronicsSMBGalaxy Microelectronics
    What it is
    Zener diode
    Maker
    Galaxy Microelectronics
    Package
    SMB
    Pins
    2
    Details
    60V, 10%, Surface Mount Zener Diodes
    Source
    Manufacturer datasheet

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

  • SMC5371BSMCDOWOSMCDOWO
    What it is
    Zener diode
    Maker
    DOWO
    Package
    SMC
    Pins
    2
    Source
    Manufacturer datasheet

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

  • 1SMB5371SMBFirst SilionSMBFirst Silion
    What it is
    Zener diode
    Maker
    First Silion
    Package
    SMB
    Pins
    2
    Details
    Zener diode: 57.0..63.0V, Zzt=40, Izt=20.0mA, 5W
    Source
    Published code list

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

  • 1SMB5371BSMBWon-Top ElectronicsSMBWon-Top Electronics
    What it is
    Zener diode
    Maker
    Won-Top Electronics
    Package
    SMB
    Pins
    2
    Details
    Zener diode: 60V±5%, Izt=20mA, Zzt=40, 5W
    Source
    Published code list

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

  • 1SMC5371SMCPanjitSMCPanjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SMC
    Pins
    2
    Details
    Z-diode: 60V±10%, 5W
    Source
    Published code list

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

  • ACZRC5371B-GSMCComchipSMCComchip
    What it is
    Zener diode
    Maker
    Comchip
    Package
    SMC
    Pins
    2
    Details
    Zener diode: 60.0V±5%, Izt=20mA, Zzt=40.0, 5W
    Source
    Published code list

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

  • CZRC5371B-GSMCComchipSMCComchip
    What it is
    Zener diode
    Maker
    Comchip
    Package
    SMC
    Pins
    2
    Details
    Zener diode: 60.0V±5%, Zzt=40.0, Izm=79mA, 5W
    Source
    Published code list

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

  • Z5SMB5371BSMBTaitron ComponentsSMBTaitron Components
    What it is
    Zener diode
    Maker
    Taitron Components
    Package
    SMB
    Pins
    2
    Details
    Zener diode: 57.0..63.0V, Izt=20mA, 5W
    Source
    Published code list

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

  • Z5SMC5371BSMCTaitron ComponentsSMCTaitron Components
    What it is
    Zener diode
    Maker
    Taitron Components
    Package
    SMC
    Pins
    2
    Details
    Zener diode: 57.0..63.0V, Izt=20mA, 5W
    Source
    Published code list

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

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.

Printed with a code easy to misread as 371B

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.