SMD code X1s
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 X1 was searched.
79 parts are printed X1s
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.
ABZT52B51-HFSOD-123Zener diode, 2 pins, ComchipZener diodeSOD-1232 pinsComchip
- What it is
- Zener diode
- Maker
- Comchip
- Package
- SOD-123
- Pins
- 2
- Details
- 51 V 0.5 mW zener diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
AO3401ASOT-23P-channel MOSFET, 3 pins, Alpha & Omega SemiconductorP-channel MOSFETSOT-233 pinsAlpha & Omega Semiconductor
- What it is
- P-channel MOSFET
- Maker
- Alpha & Omega Semiconductor
- Package
- SOT-23
- Pins
- 3
- Details
- P-channel MOSFET (8-60 V)
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: P-channel MOSFET.
AO3401ALSOT-23P-channel MOSFET, 3 pins, Alpha & Omega SemiconductorP-channel MOSFETSOT-233 pinsAlpha & Omega Semiconductor
- What it is
- P-channel MOSFET
- Maker
- Alpha & Omega Semiconductor
- Package
- SOT-23
- Pins
- 3
- Details
- P-channel MOSFET (8-60 V)
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: P-channel MOSFET.
BSD223PSOT-363Dual P-channel MOSFET, 6 pins, HottechDual P-channel MOSFETSOT-3636 pinsHottech
- What it is
- Dual P-channel MOSFET
- Maker
- Hottech
- Package
- SOT-363
- Pins
- 6
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: P-channel MOSFET pair.
BXT52B51-CSOD-123Zener diode, 2 pins, SeCoSZener diodeSOD-1232 pinsSeCoS
- What it is
- Zener diode
- Maker
- SeCoS
- Package
- SOD-123
- Pins
- 2
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
BZT52B6V8SSOD-323Zener diode, 2 pins, YFWZener diodeSOD-3232 pinsYFW
- What it is
- Zener diode
- Maker
- YFW
- Package
- SOD-323
- Pins
- 2
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
BZT52B51-HFSOD-123Zener diode, 2 pins, ComchipZener diodeSOD-1232 pinsComchip
- What it is
- Zener diode
- Maker
- Comchip
- Package
- SOD-123
- Pins
- 2
- Details
- 51 V 500 mW zener diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
BZT52B51CR-CSOD-123Zener diode, 2 pins, SeCoSZener diodeSOD-1232 pinsSeCoS
- What it is
- Zener diode
- Maker
- SeCoS
- Package
- SOD-123
- Pins
- 2
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
BZT52C51SOD-123Zener diode, 2 pins, RectronZener diodeSOD-1232 pinsRectron
- What it is
- Zener diode
- Maker
- Rectron
- Package
- SOD-123
- Pins
- 2
- Details
- 51V, 500mW, Surface Mount Zener Diodes
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
BZT52C51-CSOD-123Zener diode, 2 pins, SeCoSZener diodeSOD-1232 pinsSeCoS
- What it is
- Zener diode
- Maker
- SeCoS
- Package
- SOD-123
- Pins
- 2
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
BZT52C51-HFSOD-123Zener diode, 2 pins, ComchipZener diodeSOD-1232 pinsComchip
- What it is
- Zener diode
- Maker
- Comchip
- Package
- SOD-123
- Pins
- 2
- Details
- 51 V 0.5 mW zener diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
BZT52C51-P2-HFSOD-123Zener diode, 2 pins, ComchipZener diodeSOD-1232 pinsComchip
- What it is
- Zener diode
- Maker
- Comchip
- Package
- SOD-123
- Pins
- 2
- Details
- 51 V 0.41 mW zener diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
BZT52C51S-CSOD-323Zener diode, 2 pins, SeCoSZener diodeSOD-3232 pinsSeCoS
- What it is
- Zener diode
- Maker
- SeCoS
- Package
- SOD-323
- Pins
- 2
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
BZX384C51SOD-323Zener diode, 2 pins, Taitron ComponentsZener diodeSOD-3232 pinsTaitron Components
- What it is
- Zener diode
- Maker
- Taitron Components
- Package
- SOD-323
- Pins
- 2
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
BZX384C51-Q1SOD-323Zener diode, 2 pins, Formosa MicrosemiZener diodeSOD-3232 pinsFormosa Microsemi
- What it is
- Zener diode
- Maker
- Formosa Microsemi
- Package
- SOD-323
- Pins
- 2
- Source
- Manufacturer datasheet
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.
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.
P-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 drain, black on the source: 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. 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.
P-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 drain, black on the source: 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. 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.
Printed with a code easy to misread as X1s
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 1 more part.
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