SMD code K9 in DFN
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.
2 parts in DFN are printed K9
Not sure which one you have?
Answer up to 4 quick questions and these 21 parts are ranked, with a meter test that settles it. It works on a dead part too.
EM5213AVA-30DFNLoad switch, Excelliance MOSLoad switchExcelliance 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.
UM3730DA-29DFNLDO regulator, Union SemiconductorLDO regulatorUnion Semiconductor
- What it is
- LDO regulator
- Maker
- Union Semiconductor
- Package
- DFN
- Pins
- Not recorded
- Details
- Linear voltage regulator IC: LDO, 2.9V±2%, 150mA, +CE
- Source
- Published code list
Is it dead? The meter test is below: Voltage regulator.
13 more parts have no package on record. Nothing rules them out, so they stay.
BFCN-3700+RF filter, Mini-CircuitsRF filterMini-Circuits
- What it is
- RF filter
- Maker
- Mini-Circuits
- Package
- Not recorded
- Pins
- Not recorded
- Details
- LTCC filter, 3000-4600 MHz
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: This part.
MTAK9FEN-channel MOSFET, CYStekN-channel MOSFETCYStek
- What it is
- N-channel MOSFET
- Maker
- CYStek
- Package
- Not recorded
- Pins
- Not recorded
- Details
- 20 V, 1.4 A N-channel MOSFET
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: N-channel MOSFET.
AP8821N-29GIVoltage supervisor, Anwell SemiconductorVoltage supervisorAnwell Semiconductor
- What it is
- Voltage supervisor
- Maker
- Anwell Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 2.9V±2%, -Reset ODO, H-free
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
AP8821N-29GSVoltage supervisor, Anwell SemiconductorVoltage supervisorAnwell Semiconductor
- What it is
- Voltage supervisor
- Maker
- Anwell Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 2.9V±2%, -Reset ODO, H-free
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
AP8821N-29PIVoltage supervisor, Anwell SemiconductorVoltage supervisorAnwell Semiconductor
- What it is
- Voltage supervisor
- Maker
- Anwell Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 2.9V±2%, -Reset ODO
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
AP8821N-29PSVoltage supervisor, Anwell SemiconductorVoltage supervisorAnwell Semiconductor
- What it is
- Voltage supervisor
- Maker
- Anwell Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 2.9V±2%, -Reset ODO
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
BD46E231G-MVoltage supervisor, ROHMVoltage supervisorROHM
- What it is
- Voltage supervisor
- Maker
- ROHM
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 2.3V±1%, -MR, -Reset PPO, Rdt=100ms
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
EC95808N29C7IVoltage supervisor, E-CMOSVoltage supervisorE-CMOS
- What it is
- Voltage supervisor
- Maker
- E-CMOS
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 2.9V±2%, -Reset ODO
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
EC95808N29C7SVoltage supervisor, E-CMOSVoltage supervisorE-CMOS
- What it is
- Voltage supervisor
- Maker
- E-CMOS
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 2.9V±2%, -Reset ODO
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
LDTB123YET1GDigital transistor (PNP, resistors built in), LRCDigital transistor (PNP, resistors built in)LRC
- What it is
- Digital transistor (PNP, resistors built in)
- Maker
- LRC
- Package
- Not recorded
- Pins
- Not recorded
- Details
- PNP transistor: Sw., 50V, 500mA, B>56, R1/R2=2.2k/10k
- Source
- Published code list
Is it dead? The meter test is below: Digital transistor.
NC7SP57LFairchild SemiconductorNot recordedFairchild Semiconductor
- What it is
- Not recorded
- Maker
- Fairchild Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- CMOS logic IC: Configurable multiple-function gate
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
R5426D108CANisshinbo Micro DevicesNot recordedNisshinbo Micro Devices
- What it is
- Not recorded
- Maker
- Nisshinbo Micro Devices
- Package
- Not recorded
- Pins
- Not recorded
- Details
- CMOS-IC: Li-Ion Battery Over-charge/discharge Protection, Vc/d=1,08V
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
RN2970FSToshibaNot recordedToshiba
- What it is
- Not recorded
- Maker
- Toshiba
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Si-pnp-Digi: Dual, Sw, 20V, 50mA, 50mW, R1=4.7k
- Source
- Published code list
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.
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.
Voltage regulator
Voltage, board powered, black probe on ground. Then ohms with the power off.
Working, it reads
Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.
Dead, it reads
- Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
- Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
- Power off, input to output near 0 Ω: shorted.
- On the board:
- An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
- Compare:
- The same regulator on another rail or another board shows the right voltages and the right resistances.
- Watch for:
- Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.
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.
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.
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.
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.
Codes that begin with K9
For a marking with its end worn or burnt off. Each code has a page of its own.
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