SMD marking

D0in SOT-23-6

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.

2 parts are printed D0

Not sure which one you have?

Answer up to 4 quick questions and these 2 parts are ranked, with a meter test that settles it. It works on a dead part too.

MOSFET, all SOT-23-6, 6 pins, all Alpha & Omega Semiconductor.

AO6400SOT-23-6
What it is
MOSFET
Maker
Alpha & Omega Semiconductor
Package
SOT-23-6
Pins
6
Details
Low-voltage (12-30 V) MOSFET
Source
From the manufacturer's datasheet
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:
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.
Datasheetfor AO6400, opens in a new tab
AO6400LSOT-23-6
What it is
MOSFET
Maker
Alpha & Omega Semiconductor
Package
SOT-23-6
Pins
6
Details
Low-voltage (12-30 V) MOSFET
Source
From the manufacturer's datasheet
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:
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.
Datasheetfor AO6400L, opens in a new tab

4 more parts are printed with a code easy to misread as D0

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.

BB857printed OOInfineonNot recordedNot recordedInfineon
Printed OO on the part. Easy to misread as D0. Check that character with a loupe before you order anything.
What it is
Not recorded
Maker
Infineon
Package
Not recorded
Pins
Not recorded
Source
From the manufacturer's datasheet
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:
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.
Datasheetfor BB857, opens in a new tab
BFN16printed DDRF transistor, InfineonRF transistorNot recordedInfineon
Printed DD on the part. Easy to misread as D0. Check that character with a loupe before you order anything.
What it is
RF transistor
Maker
Infineon
Package
Not recorded
Pins
Not recorded
Source
From the manufacturer's 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:
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.
Datasheetfor BFN16, opens in a new tab
ESD321DPYprinted DDESD protection diode, 2 pins, Texas InstrumentsESD protection diode2 pinsTexas Instruments
Printed DD on the part. Easy to misread as D0. Check that character with a loupe before you order anything.
What it is
ESD protection diode
Maker
Texas Instruments
Package
Not recorded
Pins
2
Details
1-Channel 30kV ESD Protection Diode with Low Capacitance (< 1pF) in 0402 and SOD-523 Packages
Source
From the manufacturer's 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:
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.
Datasheetfor ESD321DPY, opens in a new tab
TPS7A2033DQNprinted QOLDO regulator, 4 pins, Texas InstrumentsLDO regulator4 pinsTexas Instruments
Printed QO on the part. Easy to misread as D0. Check that character with a loupe before you order anything.
What it is
LDO regulator
Maker
Texas Instruments
Package
Not recorded
Pins
4
Details
300mA, Ultra-Low-Noise, Low-IQ, High PSRR LDO
Source
From the manufacturer's datasheet
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.
Datasheetfor TPS7A2033DQN, opens in a new tab

9 more parts have codes that begin with D0

Codes that begin with D0

For a marking with its end worn or burnt off. Each one shows its full printed code.

all Texas Instruments. What differs:

LMR16006XDDCprinted D02XDC-DC converter, 6 pinsDC-DC converter6 pins
Printed D02X. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
DC-DC converter
Maker
Texas Instruments
Package
Not recorded
Pins
6
Details
SIMPLE SWITCHER® 60 V 0.6 A Buck Regulators With High Efficiency ECO Mode
Source
From the manufacturer's datasheet
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.
Datasheetfor LMR16006XDDC, opens in a new tab
LMR16006YDDCprinted D02YDC-DC converter, 6 pinsDC-DC converter6 pins
Printed D02Y. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
DC-DC converter
Maker
Texas Instruments
Package
Not recorded
Pins
6
Details
SIMPLE SWITCHER® 60 V 0.6 A Buck Regulators With High Efficiency ECO Mode
Source
From the manufacturer's datasheet
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.
Datasheetfor LMR16006YDDC, opens in a new tab
TLV70012DDCprinted ODOLDO regulator, 5 pinsLDO regulator5 pins
Printed ODO. 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
Texas Instruments
Package
Not recorded
Pins
5
Details
200-mA, Low-IQ, Low-Dropout Regulator for Portable Devices
Source
From the manufacturer's datasheet
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.
Datasheetfor TLV70012DDC, opens in a new tab
TLV70015DDCprinted ODPLDO regulator, 5 pinsLDO regulator5 pins
Printed ODP. 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
Texas Instruments
Package
Not recorded
Pins
5
Details
200-mA, Low-IQ, Low-Dropout Regulator for Portable Devices
Source
From the manufacturer's datasheet
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.
Datasheetfor TLV70015DDC, opens in a new tab
TLV70018DDCprinted ODKLDO regulator, 5 pinsLDO regulator5 pins
Printed ODK. 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
Texas Instruments
Package
Not recorded
Pins
5
Details
200-mA, Low-IQ, Low-Dropout Regulator for Portable Devices
Source
From the manufacturer's datasheet
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.
Datasheetfor TLV70018DDC, opens in a new tab
TLV70028DDCprinted ODLLDO regulator, 5 pinsLDO regulator5 pins
Printed ODL. 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
Texas Instruments
Package
Not recorded
Pins
5
Details
200-mA, Low-IQ, Low-Dropout Regulator for Portable Devices
Source
From the manufacturer's datasheet
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.
Datasheetfor TLV70028DDC, opens in a new tab
TLV70030DDCprinted ODMLDO regulator, 5 pinsLDO regulator5 pins
Printed ODM. 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
Texas Instruments
Package
Not recorded
Pins
5
Details
200-mA, Low-IQ, Low-Dropout Regulator for Portable Devices
Source
From the manufacturer's datasheet
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.
Datasheetfor TLV70030DDC, opens in a new tab
TLV70033DDCprinted ODNLDO regulator, 5 pinsLDO regulator5 pins
Printed ODN. 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
Texas Instruments
Package
Not recorded
Pins
5
Details
200-mA, Low-IQ, Low-Dropout Regulator for Portable Devices
Source
From the manufacturer's datasheet
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.
Datasheetfor TLV70033DDC, opens in a new tab
TMP20AIDRLprinted ODATemperature sensor, 6 pinsTemperature sensor6 pins
Printed ODA. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
Temperature sensor
Maker
Texas Instruments
Package
Not recorded
Pins
6
Details
±2.5°C Low-Power, Analog Out Temperature Sensor
Source
From the manufacturer's datasheet
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.
Datasheetfor TMP20AIDRL, opens in a new tab

Open this in the search to correct a character or try another package.

2 parts are printed D0

Is it dead?

Is it dead?

Printed with a code easy to misread

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Codes that begin with D0

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?

Is it dead?