SMD code 31C
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.
31C on a chip resistor
20.5 kΩ
20.5 kΩ resistor, 1%
EIA-96 precision code: 31 stands for 205 in the E96 table, and the letter C is the multiplier, × 100. These are 1% parts.
Check it with a meter
Lift one end and measure across it. A good one reads 20.5 kΩ within 1%. Measuring it in circuit reads the parallel combination of everything around it, which is almost always lower, never higher: well above 20.5 kΩ on the board is a fault. Open, or well above 20.5 kΩ, means it has failed: burnt, cracked or corroded. That does not change what to fit: the marking still says 20.5 kΩ. A burnt resistor usually means the part it feeds drew too much, so find that before fitting a new one.
On a transistor or diode body (SOT-23-5, SOT-23, SOT-353), 31C is a part code instead. Those parts are listed below.
11 parts are printed 31C
Not sure which one you have?
Answer up to 4 quick questions and these 11 parts are ranked, with a meter test that settles it. It works on a dead part too.
AAT60031C-S2SOT-23Voltage supervisor, 3 pins, Advanced Analog TechnologyVoltage supervisorSOT-233 pinsAdvanced Analog Technology
- What it is
- Voltage supervisor
- Maker
- Advanced Analog Technology
- Package
- SOT-23
- Pins
- 3
- Details
- Voltage detector IC: 3.1V±1%, -Reset ODO
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
AAT60031C-S5SOT-23-5Voltage supervisor, 5 pins, Advanced Analog TechnologyVoltage supervisorSOT-23-55 pinsAdvanced Analog Technology
- What it is
- Voltage supervisor
- Maker
- Advanced Analog Technology
- Package
- SOT-23-5
- Pins
- 5
- Details
- Voltage detector IC: 3.1V±1%, -Reset ODO
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
AAT60031C-S15SOT-143Voltage supervisor, 4 pins, Advanced Analog TechnologyVoltage supervisorSOT-1434 pinsAdvanced Analog Technology
- What it is
- Voltage supervisor
- Maker
- Advanced Analog Technology
- Package
- SOT-143
- Pins
- 4
- Details
- Voltage detector IC: 3.1V±1%, -Reset ODO
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
AAT60031C-S16SOT-89Voltage supervisor, 3 pins, Advanced Analog TechnologyVoltage supervisorSOT-893 pinsAdvanced Analog Technology
- What it is
- Voltage supervisor
- Maker
- Advanced Analog Technology
- Package
- SOT-89
- Pins
- 3
- Details
- Voltage detector IC: 3.1V±1%, -Reset ODO
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
TK11031MSOT-23-55 pins, Toko AmericaNot recordedSOT-23-55 pinsToko America
- What it is
- Not recorded
- Maker
- Toko America
- Package
- SOT-23-5
- Pins
- 5
- Details
- Thermal detector IC: Sensor (-30 to + 105°C), 10mV/°C, 4.5..10V
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
XC6104A243MRSOT-23-5Voltage supervisor, 5 pins, TorexVoltage supervisorSOT-23-55 pinsTorex
- What it is
- Voltage supervisor
- Maker
- Torex
- Package
- SOT-23-5
- Pins
- 5
- Details
- CMOS-IC: VDet 4.3V, 5%, Hst, ±Reset PPO, Wt=50ms, Rt=3.13ms
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
XC6505A431ERUSP-6CLDO regulator, 6 pins, TorexLDO regulatorUSP-6C6 pinsTorex
- What it is
- LDO regulator
- Maker
- Torex
- Package
- USP-6C
- Pins
- 6
- Details
- Linear voltage regulator IC: LDO, 4.3V±1%, 200mA, +CE
- Source
- Published code list
Is it dead? The meter test is below: Voltage regulator.
4 more parts have no package on record
TL431ACCTVoltage reference, STMicroelectronicsVoltage referenceNot recordedNot recordedSTMicroelectronics
- What it is
- Voltage reference
- Maker
- STMicroelectronics
- Package
- Not recorded
- Pins
- Not recorded
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
TL431CCTVoltage reference, STMicroelectronicsVoltage referenceNot recordedNot recordedSTMicroelectronics
- What it is
- Voltage reference
- Maker
- STMicroelectronics
- Package
- Not recorded
- Pins
- Not recorded
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
APL5301-18AAnpecNot recordedNot recordedNot recordedAnpec
- What it is
- Not recorded
- Maker
- Anpec
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage regulator
- Source
- Published code list
Is it dead? The meter test is below: Voltage regulator.
APL5301-18BAnpecNot recordedNot recordedNot recordedAnpec
- What it is
- Not recorded
- Maker
- Anpec
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage regulator
- Source
- Published code list
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.
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.
Voltage regulator
Voltage, board powered, black probe on ground. Then ohms with the power off.
Working, it reads
Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.
Dead, it reads
- Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
- Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
- Power off, input to output near 0 Ω: shorted.
- On the board:
- An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
- Compare:
- The same regulator on another rail or another board shows the right voltages and the right resistances.
- Watch for:
- Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
Printed with a code easy to misread as 31C
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 6 more parts.
Did you find your part?
Open this in the search to correct a character or try another package.