SMD code MOp
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, p, is lower case, which on NXP and Philips parts is a date or factory code, so it was set aside and MO was searched.
35 parts are printed MOp
Not sure which one you have?
Answer up to 4 quick questions and these 35 parts are ranked, with a meter test that settles it. It works on a dead part too.
BF998RSOT-143RF transistor, 4 pins, InfineonRF transistorSOT-1434 pinsInfineon
- What it is
- RF transistor
- Maker
- Infineon
- Package
- SOT-143
- Pins
- 4
- Source
- An older or alternative marking, from a published code list
Is it dead? The meter test is below: Bipolar transistor.
BF998SSOT-1434 pins, Philips SemiconductorsNot recordedSOT-1434 pinsPhilips Semiconductors
- What it is
- Not recorded
- Maker
- Philips Semiconductors
- Package
- SOT-143
- Pins
- 4
- Details
- equivalent BF966S
- Source
- Published code list
Is it dead? The meter test is below: This part.
CHP202UPTSOT-3233 pins, Chenmko EnterpriseNot recordedSOT-3233 pinsChenmko Enterprise
- What it is
- Not recorded
- Maker
- Chenmko Enterprise
- Package
- SOT-323
- Pins
- 3
- Details
- Diode: Dual, Sw, 80V, 100mA, Vf<1.2V(100mA), 4ns
- Source
- Published code list
Is it dead? The meter test is below: Silicon diode.
CJ3400SOT-23N-channel MOSFET, 3 pins, JSCJN-channel MOSFETSOT-233 pinsJSCJ
- What it is
- N-channel MOSFET
- Maker
- JSCJ
- Package
- SOT-23
- Pins
- 3
- Details
- MOSFET, N-channel, 30 V, 5.8 A
- Source
- An older or alternative marking, from a published code list
Is it dead? The meter test is below: N-channel MOSFET.
DDZ9717SOD-123Zener diode, 2 pins, Diodes IncorporatedZener diodeSOD-1232 pinsDiodes Incorporated
- What it is
- Zener diode
- Maker
- Diodes Incorporated
- Package
- SOD-123
- Pins
- 2
- Details
- Z-diode: 43V±5%, 500mW
- Source
- Published code list
Is it dead? The meter test is below: Zener diode.
DDZ9717SSOD-323Zener diode, 2 pins, Diodes IncorporatedZener diodeSOD-3232 pinsDiodes Incorporated
- What it is
- Zener diode
- Maker
- Diodes Incorporated
- Package
- SOD-323
- Pins
- 2
- Details
- Zener diode: 43V±1%, If=10mA, 150mW
- Source
- Published code list
Is it dead? The meter test is below: Zener diode.
DDZ9717TSOD-523Zener diode, 2 pins, Diodes IncorporatedZener diodeSOD-5232 pinsDiodes Incorporated
- What it is
- Zener diode
- Maker
- Diodes Incorporated
- Package
- SOD-523
- Pins
- 2
- Details
- Zener diode: 43V±1%, If=10mA, 150mW
- Source
- Published code list
Is it dead? The meter test is below: Zener diode.
DDZX9717SOD-1232 pins, Diodes IncorporatedNot recordedSOD-1232 pinsDiodes Incorporated
- What it is
- Not recorded
- Maker
- Diodes Incorporated
- Package
- SOD-123
- Pins
- 2
- Details
- Z-diode: 43V±5%, 500mW
- Source
- Published code list
Is it dead? The meter test is below: Silicon diode.
M1MA142WSOT-3233 pins, onsemiNot recordedSOT-3233 pinsonsemi
- What it is
- Not recorded
- Maker
- onsemi
- Package
- SOT-323
- Pins
- 3
- Details
- d diode ca 80V 100mA
- Source
- Published code list
Is it dead? The meter test is below: Silicon diode.
M1MA142WASOT-3233 pins, Galaxy MicroelectronicsNot recordedSOT-3233 pinsGalaxy Microelectronics
- What it is
- Not recorded
- Maker
- Galaxy Microelectronics
- Package
- SOT-323
- Pins
- 3
- Details
- Si-diode: Dual, Swi, 80V, 100mA, 150mW, Vf<1,2V(100mA), <15pF
- Source
- Published code list
Is it dead? The meter test is below: Silicon diode.
M1MA142WAT1SOT-3233 pins, onsemiNot recordedSOT-3233 pinsonsemi
- What it is
- Not recorded
- Maker
- onsemi
- Package
- SOT-323
- Pins
- 3
- Source
- Published code list
Is it dead? The meter test is below: This part.
M1MA152WSOT-233 pins, onsemiNot recordedSOT-233 pinsonsemi
- What it is
- Not recorded
- Maker
- onsemi
- Package
- SOT-23
- Pins
- 3
- Details
- d diode ca 80V 100mA
- Source
- Published code list
Is it dead? The meter test is below: Silicon diode.
M1MA152WASOT-233 pins, onsemiNot recordedSOT-233 pinsonsemi
- What it is
- Not recorded
- Maker
- onsemi
- Package
- SOT-23
- Pins
- 3
- Details
- Si-diode: Dual, Sw, 80V, 100mA, 200mW, Vf<1,2V(100mA), <15pF
- Source
- Published code list
Is it dead? The meter test is below: Silicon diode.
M1MA152WAT1SOT-233 pins, onsemiNot recordedSOT-233 pinsonsemi
- What it is
- Not recorded
- Maker
- onsemi
- Package
- SOT-23
- Pins
- 3
- Source
- Published code list
Is it dead? The meter test is below: This part.
MA3X152DSOT-233 pins, PanNot recordedSOT-233 pinsPan
- What it is
- Not recorded
- Maker
- Pan
- Package
- SOT-23
- Pins
- 3
- Details
- Si-diode: Dual, Sw, 80V, 100mA, <10ns, 15pF
- Source
- Published code list
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.
Bipolar transistor
Diode range, part lifted or its base leg off the pad.
Working, it reads
From the base, one probe colour 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.
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.
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.
N-channel MOSFET
Diode range, part lifted. Test drain to source first, then short gate to source and test again.
Working, it reads
Red probe on the source, black on the drain: about 0.4 to 0.9 V, the body diode. Open the other way. The gate reads open to both other pins, both ways.
Dead, it reads
- Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
- The gate reads low to source or drain: gate shorted. Often all three pins end up shorted together.
- No body diode at all: failed open.
- On the board
- the gate usually has a resistor to the source, so gate to source reads that resistor, which is not a fault. A drain short can be the load. Lift a leg to be sure.
- 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 diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
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.
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