SMD code 301
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.
301 on a chip resistor
300 Ω
300 Ω resistor, 5%
30 followed by 1 zero. Three digits is normally the 5% series. The same marking also reads as 300 pF on a capacitor or 300 µH on an inductor, and nothing in the code says which; the body of the part does.
Other readings of the same characters, most likely first
- 300 pF capacitor
- 300 µH inductor
Check it with a meter
Lift one end and measure across it. A good one reads 300 Ω within 5%. Measuring it in circuit reads the parallel combination of everything around it, which is almost always lower, never higher: well above 300 Ω on the board is a fault. Open, or well above 300 Ω, means it has failed: burnt, cracked or corroded. That does not change what to fit: the marking still says 300 Ω. A burnt resistor usually means the part it feeds drew too much, so find that before fitting a new one.
On a transistor or diode body (SMC, USP-6B, SOT-23-5), 301 is a part code instead. Those parts are listed below.
18 parts are printed 301
Not sure which one you have?
Answer up to 4 quick questions and these 18 parts are ranked, with a meter test that settles it. It works on a dead part too.
ACGRB301-HFSMBRectifier, 2 pins, ComchipRectifierSMB2 pinsComchip
- What it is
- Rectifier
- Maker
- Comchip
- Package
- SMB
- Pins
- 2
- Details
- 50 V, 3 A rectifier
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
ACGRC301-HFSMCRectifier, 2 pins, ComchipRectifierSMC2 pinsComchip
- What it is
- Rectifier
- Maker
- Comchip
- Package
- SMC
- Pins
- 2
- Details
- 50 V, 3 A rectifier
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
ACURB301-HFSMBRectifier, 2 pins, ComchipRectifierSMB2 pinsComchip
- What it is
- Rectifier
- Maker
- Comchip
- Package
- SMB
- Pins
- 2
- Details
- 50 V, 3 A rectifier
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
CGRB301-HFSMBRectifier, 2 pins, ComchipRectifierSMB2 pinsComchip
- What it is
- Rectifier
- Maker
- Comchip
- Package
- SMB
- Pins
- 2
- Details
- 50 V, 3 A rectifier
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
CURC301-HFSMCRectifier, 2 pins, ComchipRectifierSMC2 pinsComchip
- What it is
- Rectifier
- Maker
- Comchip
- Package
- SMC
- Pins
- 2
- Details
- 50 V, 3 A rectifier
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
FDC6301NSOT-23-6Dual N-channel MOSFET, 6 pins, onsemiDual N-channel MOSFETSOT-23-66 pinsonsemi
- What it is
- Dual N-channel MOSFET
- Maker
- onsemi
- Package
- SOT-23-6
- Pins
- 6
- Details
- Dual, N-Channel, Digital FET
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: N-channel MOSFET pair.
FDV301NSOT-23N-channel MOSFET, 3 pins, UMWN-channel MOSFETSOT-233 pinsUMW
- What it is
- N-channel MOSFET
- Maker
- UMW
- Package
- SOT-23
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: N-channel MOSFET.
TP2301-TRSOT-23-5Operational amplifier, 5 pins, 3PEAKOperational amplifierSOT-23-55 pins3PEAK
- What it is
- Operational amplifier
- Maker
- 3PEAK
- Package
- SOT-23-5
- Pins
- 5
- Details
- 20-MHz Bandwidth, Low-Noise, High-Precision Operational
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
CMJ0300SOD-123F2 pins, Central SemiconductorNot recordedSOD-123F2 pinsCentral Semiconductor
- What it is
- Not recorded
- Maker
- Central Semiconductor
- Package
- SOD-123F
- Pins
- 2
- Details
- Diode: Current limiter, Ilim=0.20..0.42mA, Vlmin=0.8V, 500mW
- Source
- Published code list
Is it dead? The meter test is below: Silicon diode.
MC33463H-30KSOT-89DC-DC converter, 3 pins, onsemiDC-DC converterSOT-893 pinsonsemi
- What it is
- DC-DC converter
- Maker
- onsemi
- Package
- SOT-89
- Pins
- 3
- Details
- VR-IC: Variable-Frequncy DC-DC conv., 3V±2,5%, 80..120KHz
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
PZM3.0NB1SOT-233 pins, NexperiaNot recordedSOT-233 pinsNexperia
- What it is
- Not recorded
- Maker
- Nexperia
- Package
- SOT-23
- Pins
- 3
- Details
- Z-diode: 3.0V±2.5%, 300mW
- Source
- Published code list
Is it dead? The meter test is below: Silicon diode.
TPA301DSOIC-88 pins, Texas InstrumentsNot recordedSOIC-88 pinsTexas Instruments
- What it is
- Not recorded
- Maker
- Texas Instruments
- Package
- SOIC-8
- Pins
- 8
- Details
- Linear IC: APA, BTL, 2.5..5.5V, 350mW(5V/8), shutdown
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
3 more parts have no package on record
TCK301GLoad switch, ToshibaLoad switchNot recordedNot recordedToshiba
- What it is
- Load switch
- Maker
- Toshiba
- Package
- Not recorded
- Pins
- Not recorded
- Details
- 28 V, Single input - Single Output Load Switch IC with Over Voltage Protection
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Load switch.
HZM3.0NB1Zener diode, RenesasZener diodeNot recordedNot recordedRenesas
- What it is
- Zener diode
- Maker
- Renesas
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Z-diode: 2.8..3.05V, 200mW
- Source
- Published code list
Is it dead? The meter test is below: Zener diode.
HZU30L-1Zener diode, RenesasZener diodeNot recordedNot recordedRenesas
- What it is
- Zener diode
- Maker
- Renesas
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Z-diode: 28.2..29.6V, 150mW
- 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.
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 pair
Diode range, part lifted. Test drain to source first, then short gate to source and test again. Test each MOSFET on its own pins, as the datasheet's pinout gives them.
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.
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.
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.
Integrated circuit
Voltage with the board powered; ohms from each pin to ground with it off.
Working, it reads
Supply pin at its voltage and the output doing what the datasheet says. Readings between pins depend on the part.
Dead, it reads
- A pin near 0 Ω to ground or to the supply pin where an identical part does not read that: failed short.
- Supply present, output stuck: failed, or its load has.
- On the board:
- A pin shorted to ground on the board can be anything on that net. Lift the pin to be sure.
- Compare:
- The surest reference is the same IC on a working board, measured pin by pin.
- Watch for:
- Its protection diodes can read like junctions between pins, even like a transistor. That proves nothing either way.
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.
Printed with a code easy to misread as 301
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.