SMD code MH in SOT-23
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.
11 parts in SOT-23 are printed MH
Not sure which one you have?
Answer up to 4 quick questions and these 33 parts are ranked, with a meter test that settles it. It works on a dead part too.
BZX84C51CC-HFSOT-23Zener diode, ComchipZener diodeComchip
- What it is
- Zener diode
- Maker
- Comchip
- Package
- SOT-23
- Pins
- 3
- Details
- 51 V 0.35 mW zener diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
2SC3606SOT-23RF transistor, ToshibaRF transistorToshiba
- What it is
- RF transistor
- Maker
- Toshiba
- Package
- SOT-23
- Pins
- 3
- Details
- NPN transistor: VHF/UHF, LN, 20V, 80mA, 150mW, 7GHz, B=30..250
- Source
- Published code list
Is it dead? The meter test is below: Bipolar transistor.
BZX84C51CCSOT-23Zener diode, JinYu semiconductorZener diodeJinYu semiconductor
- What it is
- Zener diode
- Maker
- JinYu semiconductor
- Package
- SOT-23
- Pins
- 3
- Details
- Zener diode: Dual, 48..54V, Zzt=180, Izt=2mA, 350mW
- Source
- Published code list
Is it dead? The meter test is below: Zener diode.
DDZX9711SOT-23Zener diode, Diodes IncorporatedZener diodeDiodes Incorporated
- What it is
- Zener diode
- Maker
- Diodes Incorporated
- Package
- SOT-23
- Pins
- 3
- Details
- Z-diode: 27V±5%, 500mW
- Source
- Published code list
Is it dead? The meter test is below: Zener diode.
DZ23C51SOT-23Zener diode, Luguang Electronic TechnologyZener diodeLuguang Electronic Technology
- What it is
- Zener diode
- Maker
- Luguang Electronic Technology
- Package
- SOT-23
- Pins
- 3
- Source
- Published code list
Is it dead? The meter test is below: Zener diode.
ELM7647HDBSOT-23Voltage supervisor, ELM TechnologyVoltage supervisorELM Technology
- What it is
- Voltage supervisor
- Maker
- ELM Technology
- Package
- SOT-23
- Pins
- 3
- Details
- Voltage detector IC: 4.7V±2%, +Reset PPO, Rdt=50ms
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
M1MA151KSOT-23onsemiNot recordedonsemi
- What it is
- Not recorded
- Maker
- onsemi
- Package
- SOT-23
- Pins
- 3
- Details
- Si-diode: Sw, 40V, 100mA, 200mW, Vf<1,2V(100mA), <2pF
- Source
- Published code list
Is it dead? The meter test is below: Silicon diode.
M1MA151KTSOT-23onsemiNot recordedonsemi
- What it is
- Not recorded
- Maker
- onsemi
- Package
- SOT-23
- Pins
- 3
- Details
- 40V 100mA sw diode
- Source
- Published code list
Is it dead? The meter test is below: Silicon diode.
M1MA151KT1SOT-23onsemiNot recordedonsemi
- What it is
- Not recorded
- Maker
- onsemi
- Package
- SOT-23
- Pins
- 3
- Source
- Published code list
Is it dead? The meter test is below: This part.
MCP111T-290E/TTSOT-23MicrochipNot recordedMicrochip
- What it is
- Not recorded
- Maker
- Microchip
- Package
- SOT-23
- Pins
- 3
- Source
- Published code list
Is it dead? The meter test is below: This part.
PT7M6240CHTA3ESOT-23Voltage supervisor, Pericom TechnologyVoltage supervisorPericom Technology
- What it is
- Voltage supervisor
- Maker
- Pericom Technology
- Package
- SOT-23
- Pins
- 3
- Details
- Voltage detector IC: 4.0V±1.5%, +Reset PPO, L-free
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
4 more parts have no package on record. Nothing rules them out, so they stay.
2SAR554RPNP transistor, ROHMPNP transistorROHM
- What it is
- PNP transistor
- Maker
- ROHM
- Package
- Not recorded
- Pins
- Not recorded
- Details
- PNP -1.5A -80V Middle Power Transistor
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: PNP transistor.
LFCV-1452+RF filter, Mini-CircuitsRF filterMini-Circuits
- What it is
- RF filter
- Maker
- Mini-Circuits
- Package
- Not recorded
- Pins
- Not recorded
- Details
- LTCC filter, DC-14500 MHz
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: This part.
NCP163AMX190LDO regulator, onsemiLDO regulatoronsemi
- What it is
- LDO regulator
- Maker
- onsemi
- Package
- Not recorded
- Pins
- Not recorded
- Details
- LDO Regulator - Ultra-Low Noise, High PSRR, RF and Analog Circuits
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Voltage regulator.
NCP730BMT1500LDO regulator, onsemiLDO regulatoronsemi
- What it is
- LDO regulator
- Maker
- onsemi
- Package
- Not recorded
- Pins
- Not recorded
- Details
- LDO Regulator, 150 mA, 38 V, 1 A I , with PG
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Voltage regulator.
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.
Bipolar transistor
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.
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.
Silicon diode
Diode range, part lifted or one leg off the pad. Red probe on the anode.
Working, it reads
About 0.5 to 0.8 V anode to cathode, and open the other way. Small switching diodes read about 0.6 to 0.7 V; large rectifiers can read a little lower.
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: failed open.
- A reading the wrong way round as well: 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 three-pin body can hold two diodes. With a common pin they read two junctions from that pin, just like a transistor; in series they read two drops end to end. Test each pair the datasheet names.
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.
PNP transistor
Diode range, part lifted or its base leg off the pad.
Working, it reads
Black probe on the base 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.
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.
Codes that begin with MH
For a marking with its end worn or burnt off. Each code has a page of its own.
Codes not listed here are printed on 55 more parts.
Did you find your part?
Open this in the search to correct a character or try another package.