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SMD code H1-

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.

188 parts are printed H1-

Not sure which one you have?

Answer up to 4 quick questions and these 50 parts are ranked, with a meter test that settles it. It works on a dead part too.

  • CZRV5241B-HFSOD-323Zener diode, 2 pins, ComchipZener diodeSOD-3232 pinsComchip
    What it is
    Zener diode
    Maker
    Comchip
    Package
    SOD-323
    Pins
    2
    Details
    11 V 0.2 mW zener diode
    Source
    Manufacturer datasheet

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

  • CZRV5241BS-P2-HFSOD-323Zener diode, 2 pins, ComchipZener diodeSOD-3232 pinsComchip
    What it is
    Zener diode
    Maker
    Comchip
    Package
    SOD-323
    Pins
    2
    Details
    11 V 0.2 mW zener diode
    Source
    Manufacturer datasheet

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

  • EH1AxialRectifier, 2 pins, SankenRectifierAxial2 pinsSanken
    What it is
    Rectifier
    Maker
    Sanken
    Package
    Axial
    Pins
    2
    Details
    Fast Recovery Diode (VRM = 200 V, IF(AV) = 0.6 A, trr = 4 μs)
    Source
    Manufacturer datasheet

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

  • EM5220VDTDFNLoad switch, Excelliance MOSLoad switchDFNNot recordedExcelliance MOS
    What it is
    Load switch
    Maker
    Excelliance MOS
    Package
    DFN
    Pins
    Not recorded
    Details
    Power switch
    Source
    Manufacturer datasheet

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

  • EMH1SOT-563Digital transistor (NPN, resistors built in), 6 pins, JSCJDigital transistor (NPN, resistors built in)SOT-5636 pinsJSCJ
    What it is
    Digital transistor (NPN, resistors built in)
    Maker
    JSCJ
    Package
    SOT-563
    Pins
    6
    Details
    Digital transistor (bias resistors built in), NPN, 30 mA
    Source
    Manufacturer datasheet

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

  • FH1SOD-123FRectifier, 2 pins, Good-ArkRectifierSOD-123F2 pinsGood-Ark
    What it is
    Rectifier
    Maker
    Good-Ark
    Package
    SOD-123F
    Pins
    2
    Details
    Rectifier, 50 V, 1 A
    Source
    Manufacturer datasheet

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

  • HFM101-MSOD-123Rectifier, 2 pins, Formosa MicrosemiRectifierSOD-1232 pinsFormosa Microsemi
    What it is
    Rectifier
    Maker
    Formosa Microsemi
    Package
    SOD-123
    Pins
    2
    Details
    Rectifier diode
    Source
    Manufacturer datasheet

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

  • LESD8D12CT5GSOD-882ESD protection diode, 2 pins, LRCESD protection diodeSOD-8822 pinsLRC
    What it is
    ESD protection diode
    Maker
    LRC
    Package
    SOD-882
    Pins
    2
    Details
    ESD protection diode, VRWM 12 V, IR @VRWM 1 μA, VBR Min 13.3 V
    Source
    Manufacturer datasheet

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

  • LMSZ5241BT1GSOD-123Zener diode, 2 pins, LRCZener diodeSOD-1232 pinsLRC
    What it is
    Zener diode
    Maker
    LRC
    Package
    SOD-123
    Pins
    2
    Details
    Zener diode, VZ Min 10.45 V, VZ Nom 11 V, VZ Max 11.55 V
    Source
    Manufacturer datasheet

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

  • 6 more parts have no package on record
    • HFM101-MHRectifier, Formosa MicrosemiRectifierNot recordedNot recordedFormosa Microsemi
      What it is
      Rectifier
      Maker
      Formosa Microsemi
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Rectifier diode
      Source
      Manufacturer datasheet

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

    • HFM101-MSRectifier, Formosa MicrosemiRectifierNot recordedNot recordedFormosa Microsemi
      What it is
      Rectifier
      Maker
      Formosa Microsemi
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Rectifier diode
      Source
      Manufacturer datasheet

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

    • HSP051-4M5ESD protection diode, STMicroelectronicsESD protection diodeNot recordedNot recordedSTMicroelectronics
      What it is
      ESD protection diode
      Maker
      STMicroelectronics
      Package
      Not recorded
      Pins
      Not recorded
      Source
      Manufacturer datasheet

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

    • IMH1ADigital transistor (resistors built in), ROHMDigital transistor (resistors built in)Not recordedNot recordedROHM
      What it is
      Digital transistor (resistors built in)
      Maker
      ROHM
      Package
      Not recorded
      Pins
      Not recorded
      Details
      General purpose (dual digital transistors)
      Source
      Manufacturer datasheet

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

    • LDTC123TKT1GDigital transistor (NPN, resistors built in), LRCDigital transistor (NPN, resistors built in)Not recordedNot recordedLRC
      What it is
      Digital transistor (NPN, resistors built in)
      Maker
      LRC
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Digital transistor (bias resistors built in), NPN, IC 100 mA, VCEO 50 V
      Source
      Manufacturer datasheet

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

    • LFCN-2500+RF filter, Mini-CircuitsRF filterNot recordedNot recordedMini-Circuits
      What it is
      RF filter
      Maker
      Mini-Circuits
      Package
      Not recorded
      Pins
      Not recorded
      Details
      LTCC filter
      Source
      Manufacturer datasheet

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

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.

Silicon diode

Diode range, part lifted or one leg off the pad. Red probe on the anode.

Working, it reads

About 0.5 to 0.8 V anode to cathode, and open the other way. Small switching diodes read about 0.6 to 0.7 V; large rectifiers can read a little lower.

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: failed open.
  • A reading the wrong way round as well: 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 three-pin body can hold two diodes. With a common pin they read two junctions from that pin, just like a transistor; in series they read two drops end to end. Test each pair the datasheet names.

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.

Digital transistor

Ohms range, part lifted. The datasheet gives the built-in resistors: R1 in series with the base, R2 from base to emitter.

Working, it reads

Base to emitter reads about R1 plus R2 either way round, about 20 kΩ on a 10 k and 10 k part, give or take their wide tolerance. Collector to emitter reads open. A part with no R2 reads a junction behind R1 one way instead.

Dead, it reads

  • Collector to emitter the same both ways, near 0 Ω with a continuous beep: shorted.
  • From the base, open or far above R1 plus R2: R1 has failed. Static damage shows here most often.
  • Base to emitter near 0 Ω: failed short.
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:
The readings depend on the resistor values, so an identical part elsewhere on the board is the surest reference. Measure it the same way.
Watch for:
On the diode range a good part with 10 kΩ resistors reads open on every pair, so a good part looks dead there. Use the ohms range.

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.

Digital transistor

Ohms range, part lifted. The datasheet gives the built-in resistors: R1 in series with the base, R2 from base to emitter.

Working, it reads

Base to emitter reads about R1 plus R2 either way round, about 20 kΩ on a 10 k and 10 k part, give or take their wide tolerance. Collector to emitter reads open. A part with no R2 reads a junction behind R1 one way instead.

Dead, it reads

  • Collector to emitter the same both ways, near 0 Ω with a continuous beep: shorted.
  • From the base, open or far above R1 plus R2: R1 has failed. Static damage shows here most often.
  • Base to emitter near 0 Ω: failed short.
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:
The readings depend on the resistor values, so an identical part elsewhere on the board is the surest reference. Measure it the same way.
Watch for:
On the diode range a good part with 10 kΩ resistors reads open on every pair, so a good part looks dead there. Use the ohms range.

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

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.

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