SMD code search: identify a part by its marking
3 parts are printed ST5. 19 printed with a similar-looking code.
3 parts are printed ST5
Not sure which one you have?
Answer up to 4 quick questions and these 3 parts are ranked, with a meter test that settles it. It works on a dead part too.
WS1419KT5SOT-23-5ESD protection diode, 5 pins, WayonESD protection diodeSOT-23-55 pinsWayon
- What it is
- ESD protection diode
- Maker
- Wayon
- Package
- SOT-23-5
- Pins
- 5
- Source
- Manufacturer datasheet
Is it dead?
Diode range, from the protected line to ground, part lifted if you can.
Working, it reads
A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.
Dead, it reads
- From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
- A reading both ways on a one-way part: leaky.
- A one-way part open both ways: failed open.
- On the board
- , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
- Compare:
- The same part on the next line or connector pin is the healthy reading to compare with.
- Watch for:
- A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
XC9148L43CER-GUSP-6CDC-DC converter, 6 pins, TorexDC-DC converterUSP-6C6 pinsTorex
- What it is
- DC-DC converter
- Maker
- Torex
- Package
- USP-6C
- Pins
- 6
- Details
- DC/DC voltage converter IC: PWM/PFM st-up, 1.2MHz, 4.3V±2%, 1.4A, ULVO, CrLL, ShPr, +CE
- Source
- Published code list
Is it dead?
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.
XC9148L43CPR-GSOT-89-5DC-DC converter, 5 pins, TorexDC-DC converterSOT-89-55 pinsTorex
- What it is
- DC-DC converter
- Maker
- Torex
- Package
- SOT-89-5
- Pins
- 5
- Details
- DC/DC voltage converter IC: PWM/PFM step-up, 1.2MHz, 4.3V±2%, 1.4A, ULVO, CrLL, ShPr, +CE
- Source
- Published code list
Is it dead?
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.
19 more parts are printed with a code easy to misread as ST5
Printed with a code easy to misread
One character differs, and it is one that is easy to confuse under a lamp. The odd one out is marked on each.
BC857BSprinted 57SSOT-363Complementary transistor pair (NPN and PNP), 6 pins, PanjitComplementary transistor pair (NPN and PNP)SOT-3636 pinsPanjit
Printed 57S on the part. Easy to misread as ST5. Check that character with a loupe before you order anything.
- What it is
- Complementary transistor pair (NPN and PNP)
- Maker
- Panjit
- Package
- SOT-363
- Pins
- 6
- Details
- 45V, 0.2A, General Purpose PNP Bipolar Transistor
- Source
- Manufacturer datasheet
Is it dead?
Diode range, part lifted. Test each transistor on its own pins, as the datasheet's pinout gives them.
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.
BC857BS-AUprinted 57SSOT-363Transistor, 6 pins, PanjitTransistorSOT-3636 pinsPanjit
Printed 57S on the part. Easy to misread as ST5. Check that character with a loupe before you order anything.
- What it is
- Transistor
- Maker
- Panjit
- Package
- SOT-363
- Pins
- 6
- Details
- Bipolar transistor
- Source
- Manufacturer datasheet
Is it dead?
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.
F1C575printed 575SMA2 pins, OrgNot recordedSMA2 pinsOrg
Printed 575 on the part. Easy to misread as ST5. Check that character with a loupe before you order anything.
- What it is
- Not recorded
- Maker
- Org
- Package
- SMA
- Pins
- 2
- Details
- TVS: 60V, 5A, 500W(1ms)
- Source
- Published code list
Is it dead?
Diode range, from the protected line to ground, part lifted if you can.
Working, it reads
A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.
Dead, it reads
- From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
- A reading both ways on a one-way part: leaky.
- A one-way part open both ways: failed open.
- On the board
- , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
- Compare:
- The same part on the next line or connector pin is the healthy reading to compare with.
- Watch for:
- A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
IXD5127C44DMRprinted 5TSSOT-23-5Voltage supervisor, 5 pins, IXYSVoltage supervisorSOT-23-55 pinsIXYS
Printed 5TS on the part. Easy to misread as ST5. Check that character with a loupe before you order anything.
- What it is
- Voltage supervisor
- Maker
- IXYS
- Package
- SOT-23-5
- Pins
- 5
- Details
- Voltage detector IC: 4.4V±0.8%, -Reset PPO, -MR, Rdt=400ms
- Source
- Published code list
Is it dead?
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.
LN7575FRprinted 575SOT-23-5LDO regulator, 5 pins, Shanghai Natlinear ElectronicsLDO regulatorSOT-23-55 pinsShanghai Natlinear Electronics
Printed 575 on the part. Easy to misread as ST5. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Shanghai Natlinear Electronics
- Package
- SOT-23-5
- Pins
- 5
- Details
- Linear voltage regulator IC: LDO, 7.5V±2%, 100mA
- Source
- Published code list
Is it dead?
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.
LN7575MRprinted 575SOT-23LDO regulator, 3 pins, Shanghai Natlinear ElectronicsLDO regulatorSOT-233 pinsShanghai Natlinear Electronics
Printed 575 on the part. Easy to misread as ST5. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Shanghai Natlinear Electronics
- Package
- SOT-23
- Pins
- 3
- Details
- Linear voltage regulator IC: LDO, 7.5V±2%, 100mA
- Source
- Published code list
Is it dead?
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.
MMBZ5257SPTprinted 57SSOT-23Zener diode, 3 pins, Chenmko EnterpriseZener diodeSOT-233 pinsChenmko Enterprise
Printed 57S on the part. Easy to misread as ST5. Check that character with a loupe before you order anything.
- What it is
- Zener diode
- Maker
- Chenmko Enterprise
- Package
- SOT-23
- Pins
- 3
- Details
- Zener diode: 32.34..33.66V, Izt=5mA, Zzt=88, 225mW
- Source
- Published code list
Is it dead?
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.
MMCZ5257SPTprinted 57SSOT-23Zener diode, 3 pins, Chenmko EnterpriseZener diodeSOT-233 pinsChenmko Enterprise
Printed 57S on the part. Easy to misread as ST5. Check that character with a loupe before you order anything.
- What it is
- Zener diode
- Maker
- Chenmko Enterprise
- Package
- SOT-23
- Pins
- 3
- Details
- Zener diode: 32.34..33.66V, Izt=5mA, Zzt=88, 225mW
- Source
- Published code list
Is it dead?
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.
MMHZ5257SPTprinted 57SSOD-123Zener diode, 2 pins, Chenmko EnterpriseZener diodeSOD-1232 pinsChenmko Enterprise
Printed 57S on the part. Easy to misread as ST5. Check that character with a loupe before you order anything.
- What it is
- Zener diode
- Maker
- Chenmko Enterprise
- Package
- SOD-123
- Pins
- 2
- Details
- Zener diode: 32.34..33.66V, Izt=5mA, Zzt=88, 225mW
- Source
- Published code list
Is it dead?
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.
S5KP7.5printed 57.5D2PAKTVS diode, 3 pins, EIC SemiconductorTVS diodeD2PAK3 pinsEIC Semiconductor
Printed 57.5 on the part. Easy to misread as ST5. Check that character with a loupe before you order anything.
- What it is
- TVS diode
- Maker
- EIC Semiconductor
- Package
- D2PAK
- Pins
- 3
- Details
- Transient voltage supressor: Vbr=8.33..10.2V, Vrwm=7.5V, 350A, 5000W(1ms)
- Source
- Published code list
Is it dead?
Diode range, from the protected line to ground, part lifted if you can.
Working, it reads
A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.
Dead, it reads
- From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
- A reading both ways on a one-way part: leaky.
- A one-way part open both ways: failed open.
- On the board
- , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
- Compare:
- The same part on the next line or connector pin is the healthy reading to compare with.
- Watch for:
- A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
S5KP75printed 575D2PAKTVS diode, 3 pins, EIC SemiconductorTVS diodeD2PAK3 pinsEIC Semiconductor
Printed 575 on the part. Easy to misread as ST5. Check that character with a loupe before you order anything.
- What it is
- TVS diode
- Maker
- EIC Semiconductor
- Package
- D2PAK
- Pins
- 3
- Details
- Transient voltage supressor: Vbr=83.3..102V, Vrwm=75V, 37A, 5000W(1ms)
- Source
- Published code list
Is it dead?
Diode range, from the protected line to ground, part lifted if you can.
Working, it reads
A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.
Dead, it reads
- From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
- A reading both ways on a one-way part: leaky.
- A one-way part open both ways: failed open.
- On the board
- , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
- Compare:
- The same part on the next line or connector pin is the healthy reading to compare with.
- Watch for:
- A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
SST175printed S75SOT-233 pins, SiliconixNot recordedSOT-233 pinsSiliconix
Printed S75 on the part. Easy to misread as ST5. Check that character with a loupe before you order anything.
- What it is
- Not recorded
- Maker
- Siliconix
- Package
- SOT-23
- Pins
- 3
- Details
- p-FET: Sw, 30V, 350mW, Idss=70mA, Rds(on)=125Ω, 15/20ns
- Source
- Published code list
Is it dead?
Diode range, part lifted. Test drain to source first, then short gate to source and test again.
Working, it reads
One way between drain and source reads about 0.4 to 0.9 V, the body diode, and the other way open. The gate reads open to both other pins.
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.
- No body diode at all: failed open.
- On the board
- the gate usually has a resistor to the source, which reads as that resistor and 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.
UM1440S-55printed 5T5SOT-23-5LDO regulator, 5 pins, Union SemiconductorLDO regulatorSOT-23-55 pinsUnion Semiconductor
Printed 5T5 on the part. Easy to misread as ST5. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Union Semiconductor
- Package
- SOT-23-5
- Pins
- 5
- Details
- Linear voltage regulator IC: LDO, 5.5V±3%, 30mA, +CE
- Source
- Published code list
Is it dead?
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.
XC6127C44DMRprinted 5TSSOT-23-5Voltage supervisor, 5 pins, TorexVoltage supervisorSOT-23-55 pinsTorex
Printed 5TS on the part. Easy to misread as ST5. Check that character with a loupe before you order anything.
- What it is
- Voltage supervisor
- Maker
- Torex
- Package
- SOT-23-5
- Pins
- 5
- Details
- Voltage detector IC: 4.4V±0.8%, -Reset PPO, -MR, Rdt=400ms
- Source
- Published code list
Is it dead?
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.
XC9148D43CER-Gprinted S75USP-6CDC-DC converter, 6 pins, TorexDC-DC converterUSP-6C6 pinsTorex
Printed S75 on the part. Easy to misread as ST5. Check that character with a loupe before you order anything.
- What it is
- DC-DC converter
- Maker
- Torex
- Package
- USP-6C
- Pins
- 6
- Details
- DC/DC voltage converter IC: PWM/PFM st-up, 1.2MHz, 4.3V±2%, 1.4A, CrLL, ShPr, CL, +CE
- Source
- Published code list
Is it dead?
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.
XC9148D43CPR-Gprinted S75SOT-89-5DC-DC converter, 5 pins, TorexDC-DC converterSOT-89-55 pinsTorex
Printed S75 on the part. Easy to misread as ST5. Check that character with a loupe before you order anything.
- What it is
- DC-DC converter
- Maker
- Torex
- Package
- SOT-89-5
- Pins
- 5
- Details
- DC/DC voltage converter IC: PW M/PFM step-up, 1.2MHz, 4.3V±2%, 1.4A, CrLL, ShPr, CL, +CE
- Source
- Published code list
Is it dead?
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.
XC6502242Mprinted 57SSOT-23LDO regulator, 3 pins, TorexLDO regulatorSOT-233 pinsTorex
Printed 57S on the part. Easy to misread as ST5. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Torex
- Package
- SOT-23
- Pins
- 3
- Details
- Linear voltage regulator IC: LDO, 2.4V±2%, 200mA
- Source
- Published code list
Is it dead?
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.
XC6502242Pprinted 57SSOT-89LDO regulator, 3 pins, TorexLDO regulatorSOT-893 pinsTorex
Printed 57S on the part. Easy to misread as ST5. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Torex
- Package
- SOT-89
- Pins
- 3
- Details
- Linear voltage regulator IC: LDO, 2.4V±2%, 200mA
- Source
- Published code list
Is it dead?
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.
ZXTN19055DZprinted S75SOT-893 pins, Diodes IncorporatedNot recordedSOT-893 pinsDiodes Incorporated
Printed S75 on the part. Easy to misread as ST5. Check that character with a loupe before you order anything.
- What it is
- Not recorded
- Maker
- Diodes Incorporated
- Package
- SOT-89
- Pins
- 3
- Details
- npn 55V 6A 2.1W low Vcesat
- Source
- Published code list
Is it dead?
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.
11 more parts have codes that begin with ST5
Codes that begin with ST5
For a marking with its end worn or burnt off. Each one shows its full printed code.
EMC5754-00VF05GRRprinted 5754SOT-23-55 pinsNot recordedSOT-23-55 pinsNot recorded
Printed 5754. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Not recorded
- Maker
- Not recorded
- Package
- SOT-23-5
- Pins
- 5
- Details
- Charge controller
- Source
- Published code list
Is it dead?
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.
EMC5754-4DVF05GRRprinted 5754SOT-23-55 pinsNot recordedSOT-23-55 pinsNot recorded
Printed 5754. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Not recorded
- Maker
- Not recorded
- Package
- SOT-23-5
- Pins
- 5
- Details
- Charge controller
- Source
- Published code list
Is it dead?
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.
MIC5357-3.3/1.8YMMEprinted 57SGMSOP-8LDO regulator, 8 pins, MicrelLDO regulatorMSOP-88 pinsMicrel
Printed 57SG. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- LDO regulator
- Maker
- Micrel
- Package
- MSOP-8
- Pins
- 8
- Details
- Linear voltage regulator IC: LDO, Dual out, Vo1/Vo2=3.3V/1.8V±2%, 500mA, +CE
- Source
- Published code list
Is it dead?
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.
MIC5357-3.3/2.8YMMEprinted 57SMMSOP-8LDO regulator, 8 pins, MicrelLDO regulatorMSOP-88 pinsMicrel
Printed 57SM. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- LDO regulator
- Maker
- Micrel
- Package
- MSOP-8
- Pins
- 8
- Details
- Linear voltage regulator IC: LDO, Dual out, Vo1/Vo2=3.3V/2.8V±2%, 500mA, +CE
- Source
- Published code list
Is it dead?
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.
S5KP7.5Aprinted 57.5AD2PAKTVS diode, 3 pins, EIC SemiconductorTVS diodeD2PAK3 pinsEIC Semiconductor
Printed 57.5A. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- TVS diode
- Maker
- EIC Semiconductor
- Package
- D2PAK
- Pins
- 3
- Details
- Transient voltage supressor: Vbr=8.33..9.21V, Vrwm=7.5V, 388A, 5000W(1ms)
- Source
- Published code list
Is it dead?
Diode range, from the protected line to ground, part lifted if you can.
Working, it reads
A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.
Dead, it reads
- From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
- A reading both ways on a one-way part: leaky.
- A one-way part open both ways: failed open.
- On the board
- , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
- Compare:
- The same part on the next line or connector pin is the healthy reading to compare with.
- Watch for:
- A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
S5KP7.5Cprinted 57.5CD2PAKTVS diode, 3 pins, EIC SemiconductorTVS diodeD2PAK3 pinsEIC Semiconductor
Printed 57.5C. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- TVS diode
- Maker
- EIC Semiconductor
- Package
- D2PAK
- Pins
- 3
- Details
- Transient voltage supressor: Vbr=8.33..10.2V, Vrwm=7.5V, 350A, 5000W(1ms), Bidir.
- Source
- Published code list
Is it dead?
Diode range, from the protected line to ground, part lifted if you can.
Working, it reads
A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.
Dead, it reads
- From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
- A reading both ways on a one-way part: leaky.
- A one-way part open both ways: failed open.
- On the board
- , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
- Compare:
- The same part on the next line or connector pin is the healthy reading to compare with.
- Watch for:
- A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
S5KP7.5CAprinted 57.5CAD2PAKTVS diode, 3 pins, EIC SemiconductorTVS diodeD2PAK3 pinsEIC Semiconductor
Printed 57.5CA. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- TVS diode
- Maker
- EIC Semiconductor
- Package
- D2PAK
- Pins
- 3
- Details
- Transient voltage supressor: Vbr=8.33..9.21V, Vrwm=7.5V, 388A, 5000W(1ms), Bidir.
- Source
- Published code list
Is it dead?
Diode range, from the protected line to ground, part lifted if you can.
Working, it reads
A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.
Dead, it reads
- From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
- A reading both ways on a one-way part: leaky.
- A one-way part open both ways: failed open.
- On the board
- , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
- Compare:
- The same part on the next line or connector pin is the healthy reading to compare with.
- Watch for:
- A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
S5KP75Aprinted 575AD2PAKTVS diode, 3 pins, EIC SemiconductorTVS diodeD2PAK3 pinsEIC Semiconductor
Printed 575A. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- TVS diode
- Maker
- EIC Semiconductor
- Package
- D2PAK
- Pins
- 3
- Details
- Transient voltage supressor: Vbr=83.3..92.1V, Vrwm=75V, 41A, 5000W(1ms)
- Source
- Published code list
Is it dead?
Diode range, from the protected line to ground, part lifted if you can.
Working, it reads
A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.
Dead, it reads
- From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
- A reading both ways on a one-way part: leaky.
- A one-way part open both ways: failed open.
- On the board
- , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
- Compare:
- The same part on the next line or connector pin is the healthy reading to compare with.
- Watch for:
- A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
S5KP75Cprinted 575CD2PAKTVS diode, 3 pins, EIC SemiconductorTVS diodeD2PAK3 pinsEIC Semiconductor
Printed 575C. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- TVS diode
- Maker
- EIC Semiconductor
- Package
- D2PAK
- Pins
- 3
- Details
- Transient voltage supressor: Vbr=83.3..102V, Vrwm=75V, 37A, 5000W(1ms), Bidir.
- Source
- Published code list
Is it dead?
Diode range, from the protected line to ground, part lifted if you can.
Working, it reads
A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.
Dead, it reads
- From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
- A reading both ways on a one-way part: leaky.
- A one-way part open both ways: failed open.
- On the board
- , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
- Compare:
- The same part on the next line or connector pin is the healthy reading to compare with.
- Watch for:
- A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
S5KP75CAprinted 575CAD2PAKTVS diode, 3 pins, EIC SemiconductorTVS diodeD2PAK3 pinsEIC Semiconductor
Printed 575CA. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- TVS diode
- Maker
- EIC Semiconductor
- Package
- D2PAK
- Pins
- 3
- Details
- Transient voltage supressor: Vbr=83.3..92.1V, Vrwm=75V, 41A, 5000W(1ms), Bidir.
- Source
- Published code list
Is it dead?
Diode range, from the protected line to ground, part lifted if you can.
Working, it reads
A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.
Dead, it reads
- From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
- A reading both ways on a one-way part: leaky.
- A one-way part open both ways: failed open.
- On the board
- , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
- Compare:
- The same part on the next line or connector pin is the healthy reading to compare with.
- Watch for:
- A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
1 more part has no package on record
R1511S075Bprinted S75BLDO regulator, RicohLDO regulatorNot recordedNot recordedRicoh
Printed S75B. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- LDO regulator
- Maker
- Ricoh
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Linear voltage regulator IC: LDO, 7.5V±1%, 300mA, +CE
- Source
- Published code list
Is it dead?
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.
Did you find your part?
One code, several parts
Marking codes are not unique. In the standard code book, 6H on a SOT-23 is an NPN transistor, a varicap, an N-channel JFET, two digital transistors, a 3.6 V voltage detector: six parts from five makers. So a search shows the parts we hold under that code and under codes easily misread as it, with only the columns that tell them apart.
- NPN transistor
- Varicap
- N-channel JFET
- Digital transistor ×2
- 3.6 V voltage detector
When more than one is left
Tap Help me choose. Up to 4 quick answers: whether the part has failed, then what separates the parts left. Those get ranked with the reasoning and a test that settles it. That uses one identification: 2 a month are free without an account, and 3 with a free account.
When you cannot read it
Tap the camera in the field. We read the characters, keep the ones we are unsure of, and search every reading. A photo too soft to read is turned back on your phone first; if it is the only one you can get, you can still send it.
Get the app
The same search on your phone, and a camera with a light, zoom and tap to focus for a marking you cannot read. Sign in with your email address to use the same account.
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