SMD code X40
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.
8 parts are printed X40
Not sure which one you have?
Answer up to 4 quick questions and these 8 parts are ranked, with a meter test that settles it. It works on a dead part too.
TPV8308LD400-S6TRSOT-23-6Voltage supervisor, 6 pins, 3PEAKVoltage supervisorSOT-23-66 pins3PEAK
- What it is
- Voltage supervisor
- Maker
- 3PEAK
- Package
- SOT-23-6
- Pins
- 6
- Details
- Low Quiescent Current Supervisory Circuits with Programmable
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
IXD2110D401MRSOT-23-5DC-DC converter, 5 pins, IXYSDC-DC converterSOT-23-55 pinsIXYS
- What it is
- DC-DC converter
- Maker
- IXYS
- Package
- SOT-23-5
- Pins
- 5
- Details
- DC/DC voltage converter IC: PFM st-up, 100kHz, 4.0V±2.5%, 400mA, +CE
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
KIC73C40T2SOT-23Voltage supervisor, 3 pins, KECVoltage supervisorSOT-233 pinsKEC
- What it is
- Voltage supervisor
- Maker
- KEC
- Package
- SOT-23
- Pins
- 3
- Details
- Voltage detector IC: 4.0V±1%, -Reset PPO, Rdt=100ms
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
MMBZ59B40SOT-23Zener diode, 3 pins, Silicon-Based TechnologyZener diodeSOT-233 pinsSilicon-Based Technology
- What it is
- Zener diode
- Maker
- Silicon-Based Technology
- Package
- SOT-23
- Pins
- 3
- Details
- Zener diode: 9.50..10.50V, Zzt=17, Izt=20mA, 400mW
- Source
- Published code list
Is it dead? The meter test is below: Zener diode.
R1172N181A5SOT-23-55 pins, Nisshinbo Micro DevicesNot recordedSOT-23-55 pinsNisshinbo Micro Devices
- What it is
- Not recorded
- Maker
- Nisshinbo Micro Devices
- Package
- SOT-23-5
- Pins
- 5
- Details
- VR-IC: LDO, -CE, 1.85V±2%, 1A
- Source
- Published code list
Is it dead? The meter test is below: Voltage regulator.
RP300N28ABSOT-23-5Voltage supervisor, 5 pins, RicohVoltage supervisorSOT-23-55 pinsRicoh
- What it is
- Voltage supervisor
- Maker
- Ricoh
- Package
- SOT-23-5
- Pins
- 5
- Details
- Voltage detector IC: 2.8V±1%, -Reset ODO, -MR, Rdt=50ms
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
XC9110D401MRSOT-23-5DC-DC converter, 5 pins, TorexDC-DC converterSOT-23-55 pinsTorex
- What it is
- DC-DC converter
- Maker
- Torex
- Package
- SOT-23-5
- Pins
- 5
- Details
- DC/DC voltage converter IC: PFM st-up, 100kHz, 4.0V±2.5%, 400mA, +CE
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
1 more part has no package on record
KIC73C40M2Voltage supervisor, KECVoltage supervisorNot recordedNot recordedKEC
- What it is
- Voltage supervisor
- Maker
- KEC
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 4.0V±1%, -Reset PPO, Rdt=100ms
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
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.
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.
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.
Printed with a code easy to misread as X40
One character differs, and it is one that is easy to confuse under a lamp. Each code has a page of its own.
Codes that begin with X40
For a marking with its end worn or burnt off. Each code has a page of its own.
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