SMD code UCs
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.
The last letter, s, is lower case, which on NXP and Philips parts is a date or factory code, so it was set aside and UC was searched.
68 parts are printed UCs
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-C3V9SOD-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
- 3.9 V approx. ±5% voltage regulator (Zener) diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
CHT857BTGPSOT-416PNP transistor, 3 pins, ChenmkoPNP transistorSOT-4163 pinsChenmko
- What it is
- PNP transistor
- Maker
- Chenmko
- Package
- SOT-416
- Pins
- 3
- Details
- PNP Muti-Chip General Purpose Amplifier, 45 V, 0.1 A
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: PNP transistor.
CZRF6V2B-HFSOD-323Zener diode, 2 pins, ComchipZener diodeSOD-3232 pinsComchip
- What it is
- Zener diode
- Maker
- Comchip
- Package
- SOD-323
- Pins
- 2
- Details
- 6.2 V 0.2 mW zener diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
LBZB84C3V3LT1GSOT-23Zener diode, 3 pins, LRCZener diodeSOT-233 pinsLRC
- What it is
- Zener diode
- Maker
- LRC
- Package
- SOT-23
- Pins
- 3
- Details
- Zener diode, VZ Min 3.1 V, VZ Nom 3.3 V, VZ Max 3.5 V
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
MMSZ4695SOD-123Zener diode, 2 pins, VishayZener diodeSOD-1232 pinsVishay
- What it is
- Zener diode
- Maker
- Vishay
- Package
- SOD-123
- Pins
- 2
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
MMSZ4695-GSOD-123Zener diode, 2 pins, VishayZener diodeSOD-1232 pinsVishay
- What it is
- Zener diode
- Maker
- Vishay
- Package
- SOD-123
- Pins
- 2
- Details
- 8.7 V Zener diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
9 more parts have no package on record
ACZRQC6V2B-HFZener diode, ComchipZener diodeNot recordedNot recordedComchip
- What it is
- Zener diode
- Maker
- Comchip
- Package
- Not recorded
- Pins
- Not recorded
- Details
- 6.2 V 0.125 mW zener diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
ACZRUC6V2B-HFZener diode, ComchipZener diodeNot recordedNot recordedComchip
- What it is
- Zener diode
- Maker
- Comchip
- Package
- Not recorded
- Pins
- Not recorded
- Details
- 6.36 V 0.15 mW zener diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
BCR101L3Digital transistor (resistors built in), InfineonDigital transistor (resistors built in)Not recordedNot recordedInfineon
- What it is
- Digital transistor (resistors built in)
- Maker
- Infineon
- Package
- Not recorded
- Pins
- Not recorded
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Digital transistor.
CZRFR6V2B-HFZener diode, ComchipZener diodeNot recordedNot recordedComchip
- What it is
- Zener diode
- Maker
- Comchip
- Package
- Not recorded
- Pins
- Not recorded
- Details
- 6.2 V 0.2 mW zener diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
CZRQC6V2B-HFZener diode, ComchipZener diodeNot recordedNot recordedComchip
- What it is
- Zener diode
- Maker
- Comchip
- Package
- Not recorded
- Pins
- Not recorded
- Details
- 6.2 V 0.125 mW zener diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
CZRU6V2B-HFZener diode, ComchipZener diodeNot recordedNot recordedComchip
- What it is
- Zener diode
- Maker
- Comchip
- Package
- Not recorded
- Pins
- Not recorded
- Details
- 6.2 V 0.15 mW zener diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
CZRUR6V2B-HFZener diode, ComchipZener diodeNot recordedNot recordedComchip
- What it is
- Zener diode
- Maker
- Comchip
- Package
- Not recorded
- Pins
- Not recorded
- Details
- 6.05 V 0.15 mW zener diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
ESDBUC3V3AE1ESD protection diode, JSCJESD protection diodeNot recordedNot recordedJSCJ
- What it is
- ESD protection diode
- Maker
- JSCJ
- Package
- Not recorded
- Pins
- Not recorded
- Details
- ESD protection diode, VRWM 3.3 V
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
KDS4148ESwitching diode, KECSwitching diodeNot recordedNot recordedKEC
- What it is
- Switching diode
- Maker
- KEC
- Package
- Not recorded
- Pins
- Not recorded
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon 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.
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.
PNP transistor
Diode range, part lifted or its base leg off the pad.
Working, it reads
Black probe on the base reads about 0.6 to 0.75 V to the emitter and to the collector, and open the other way round. Collector to emitter reads open both ways.
Dead, it reads
- Collector to emitter the same both ways, near 0 V with a continuous beep: shorted. The commonest failure.
- The base the same both ways to another pin, near 0 V or a middling value: a shorted junction.
- Only one junction reads, or none: a junction has failed open. It then looks like a diode.
- A reading the wrong way round, where it should be open: 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 pair of diodes with a common pin reads just like a transistor, and some transistors carry a built-in diode or resistor. The datasheet says which.
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.
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.
Printed with a code easy to misread as UCs
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 15 more parts.
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Open this in the search to correct a character or try another package.