SMD code U8-
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.
72 parts are printed U8-
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.
BZX84J-C39SOD-323Zener diode, 2 pins, NexperiaZener diodeSOD-3232 pinsNexperia
- What it is
- Zener diode
- Maker
- Nexperia
- Package
- SOD-323
- Pins
- 2
- Pinout
- 1 cathode
- 2 anode
- Details
- 39 V approx. ±5% voltage regulator (Zener) diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
BZX584C18SOD-523Zener diode, 2 pins, Blue RocketZener diodeSOD-5232 pinsBlue Rocket
- What it is
- Zener diode
- Maker
- Blue Rocket
- Package
- SOD-523
- Pins
- 2
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
CPDZD18VSB-HFDFN0603-2ESD protection diode, 2 pins, ComchipESD protection diodeDFN0603-22 pinsComchip
- What it is
- ESD protection diode
- Maker
- Comchip
- Package
- DFN0603-2
- Pins
- 2
- Details
- 18 V bidirectional ESD protection diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
CZRF4V3B-HFSOD-323Zener diode, 2 pins, ComchipZener diodeSOD-3232 pinsComchip
- What it is
- Zener diode
- Maker
- Comchip
- Package
- SOD-323
- Pins
- 2
- Details
- 4.3 V 0.2 mW zener diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
MM3Z20VSSOD-323Zener diode, 2 pins, onsemiZener diodeSOD-3232 pinsonsemi
- What it is
- Zener diode
- Maker
- onsemi
- Package
- SOD-323
- Pins
- 2
- Details
- Zener Voltage Regulators MM3ZxxxST1G Series, SZMM3ZxxxST1G Series
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
MM5Z18SOD-523Zener diode, 2 pins, YFWZener diodeSOD-5232 pinsYFW
- What it is
- Zener diode
- Maker
- YFW
- Package
- SOD-523
- Pins
- 2
- Details
- Zener diode, 10 V, 0.01 A
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
MM5Z18BSOD-523Zener diode, 2 pins, RectronZener diodeSOD-5232 pinsRectron
- What it is
- Zener diode
- Maker
- Rectron
- Package
- SOD-523
- Pins
- 2
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
8 more parts have no package on record
ACZRQC4V3B-HFZener diode, ComchipZener diodeNot recordedNot recordedComchip
- What it is
- Zener diode
- Maker
- Comchip
- Package
- Not recorded
- Pins
- Not recorded
- Details
- 4.3 V 0.125 mW zener diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
ACZRUC4V3B-HFZener diode, ComchipZener diodeNot recordedNot recordedComchip
- What it is
- Zener diode
- Maker
- Comchip
- Package
- Not recorded
- Pins
- Not recorded
- Details
- 4.41 V 0.15 mW zener diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
BAR88-02LRHPIN diode, InfineonPIN diodeNot recordedNot recordedInfineon
- What it is
- PIN diode
- Maker
- Infineon
- Package
- Not recorded
- Pins
- Not recorded
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: PIN diode or varicap.
BZT52C18KZener diode, Taiwan SemiconductorZener diodeNot recordedNot recordedTaiwan Semiconductor
- What it is
- Zener diode
- Maker
- Taiwan Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
CZRFR4V3B-HFZener diode, ComchipZener diodeNot recordedNot recordedComchip
- What it is
- Zener diode
- Maker
- Comchip
- Package
- Not recorded
- Pins
- Not recorded
- Details
- 4.3 V 0.2 mW zener diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
CZRQC4V3B-HFZener diode, ComchipZener diodeNot recordedNot recordedComchip
- What it is
- Zener diode
- Maker
- Comchip
- Package
- Not recorded
- Pins
- Not recorded
- Details
- 4.3 V 0.125 mW zener diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
CZRU4V3B-HFZener diode, ComchipZener diodeNot recordedNot recordedComchip
- What it is
- Zener diode
- Maker
- Comchip
- Package
- Not recorded
- Pins
- Not recorded
- Details
- 4.3 V 0.15 mW zener diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
CZRUR4V3B-HFZener diode, ComchipZener diodeNot recordedNot recordedComchip
- What it is
- Zener diode
- Maker
- Comchip
- Package
- Not recorded
- Pins
- Not recorded
- Details
- 4.3 V 0.15 mW zener diode
- Source
- Manufacturer datasheet
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.
PIN diode or varicap
Diode range, part lifted or one leg off the pad. Red probe on the anode.
Working, it reads
About 0.6 to 0.9 V anode to cathode, and open the other way.
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.
- 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 varicap that has drifted in capacitance reads normal on a meter. Only a capacitance meter or the tuning itself shows it.
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.
Printed with a code easy to misread as U8-
One character differs, and it is one that is easy to confuse under a lamp. Each code has a page of its own.
Codes not listed here are printed on 4 more parts.
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