Name: /Tools-Info/J2831
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J2831 (Vishay) P-Channel MOSFET (TO-92)

is a P-channel enhancement-mode MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) in a through-hole TO-92 package. Like the BS250, it is a vertical DMOS transistor – meaning the conduction channel is formed vertically through the silicon body. The source terminal (pin 1) is typically tied to the more positive voltage, and the device turns on when the gate is driven to a lower potential (negative V_GS) relative to the source. Its gate is insulated from the silicon channel by a thin oxide (traditionally SiO₂), and the gate conductor is usually doped polysilicon or metal. The MOSFET’s drain–source voltage rating (V_DS) is typically in the tens of volts (often ~30–60 V range for this class), and it can handle a few hundred milliamps of current. The TO-92 package is a small plastic/epoxy mold with three leads for easy through-hole mounting. In operation, J2831 is used as a high-side or load switch transistor (conducting in the P-channel when V_GS is negative) in low-voltage DC circuits.

P-channel MOSFETs like the J2831 are widely used for high-side switching and load switching in power electronics. Typical applications include battery-powered and portable devices, power management and protection circuits, and other situations where a switch is needed between the supply rail and the load. For example, they can drive relays, lamps, and motors on the high side of a circuit. They are common in automotive and industrial control electronics, as well as computer and consumer products, wherever positive-side switching is needed. J2831’s characteristics (low gate threshold, moderate current capability, simple drive) make it suitable for DC–DC converters, load dumps, charger circuits, and low-voltage power supplies. It is also used in small battery charger circuits and portable electronics for reverse-polarity protection or reverse-charging prevention. In summary, J2831 finds use in relay/solenoid drivers, display backlight controls, memory or sensor drivers, motor controllers, and general-purpose high-side switches.

How EstiSource Helps

Global Stock & Pricing: EstiSource aggregates distributor inventory and pricing data. For example, we can show J2831 availability and lead-times from multiple suppliers (one listing shows 68k in stock and 8–10 week OEM lead). This helps buyers quickly find the best source or necessary alternatives. Cost Breakdown: EstiSource provides detailed cost analysis (including hidden costs like test/packaging). For instance, assembly and final testing can be ~30% of a chip’s cost; we include such factors to give realistic unit costs. Supplier Matchmaking: We connect buyers with authorized Vishay distributors or franchised suppliers to ensure authenticity and compliance. Our team can expedite RFQs and negotiate terms for both prototypes and mass orders. Compliance Verification: We verify component data (e.g. RoHS status, spec updates). For J2831, we confirm it is lead-free/RoHS-compliant, avoiding costly mistakes. Alternates & BOM Optimization: If J2831 supply is tight, EstiSource suggests equivalent parts (other P-channel MOSFETs or footprint-compatible substitutes) and provides performance/cost comparisons. Technical Support: Our experts help interpret datasheets and manufacturer bulletins, and advise on design concerns (thermal limits of TO-92, gate drive considerations, etc.), streamlining engineering decisions.

Why Choose EstiSource for Sourcing J2831

Comprehensive Data: We combine manufacturing insights, supplier databases, and cost models to give a one-stop sourcing solution. For example, our estimates consider test and packaging overhead, and our database tracks real-time stock like the 68k units shown for J2831. B2B Focus: Tailored for procurement and engineering teams, EstiSource speaks both technical and commercial language. We understand component specs and B2B pain points (lead-time, MOQ, compliance). Accuracy & Trust: By cross-referencing manufacturer specs (Vishay datasheets) and distributor info, we minimize errors. All material and compliance claims are verified (e.g. “RoHS” status). Speed & Efficiency: Instead of chasing multiple sites, you get consolidated quotes and analyses. This accelerates decision-making, critical for tight development schedules. Value Add: Beyond raw data, we offer strategic advice. For example, if J2831’s long lead-time threatens a project, we proactively evaluate alternatives and help redesign into a more available device. EstiSource’s sourcing platform and expertise ensure that procuring parts like the J2831 is faster, safer, and more cost-effective.

1. Material Composition

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2. Manufacturing Process

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Manufacturing J2831 involves two major phases: wafer fabrication of the MOSFET die, and package assembly into the TO-92 case. The key steps are:

Wafer Fabrication: Start with a polished silicon wafer. Through cleaning, oxidation, photolithography, doping, deposition, etching, and planarization steps, the MOSFET structures are formed layer by layer. For example, photoresist is patterned and exposed by UV light to define source/drain and gate regions, then ion implantation introduces dopants (phosphorus or boron) to create N- and P-type regions. Thin films (SiO₂, polysilicon, metal) are deposited by CVD/PVD and etched to form gates, contacts, and interconnects. Multiple masks are used for each transistor layer until the complete transistor structure is on the wafer.
Wafer Test and Dicing: The finished wafer is electrically tested for functionality. Good dies are then sawed (diced) into individual chips.
Die Attach: Each die is then placed and bonded (using die-attach epoxy or solder) onto the copper lead-frame paddle. This provides mechanical support and thermal path.
Wire Bonding: Fine bonding wires (gold or aluminum) connect the die’s source, drain, and gate bond pads to the corresponding lead-frame leads.
Encapsulation (Molding): The lead-frame and attached die are placed in a mold. Molten epoxy or plastic compound is injected and cured around the die and frame, forming the TO-92 package. Only the trimmed lead ends remain exposed. This encapsulation step electrically isolates the chip and secures the assembly.
Lead Trim & Form: After molding, the excess frame is cut away, and the three leads are trimmed and bent into the standard TO-92 pin geometry.
Marking & Final Test: The part number and date code are printed on the flat face. Finally, each packaged device undergoes electrical testing to ensure it meets specifications.

Throughout manufacturing, controls on RoHS compliance (lead-free materials) and quality (yield, device testing) are enforced. The above process (clean room wafer fab, then assembly at an OSAT) typically spans weeks to months.

3. Challenges and Limitations

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Performance Constraints

Challenge: As a P-channel MOSFET, J2831 inherently has higher on-resistance (R_DS(on)) and input capacitance than an equivalent N-channel device. This means it dissipates more power (I²R losses) for the same current. Its R_DS(on) is on the order of 10–50 Ω (tens of ohms), so it is not suitable for high-current loads; continuous current ratings are typically only a few hundred milliamps. In high-speed switching, the larger gate charge and slower switching speed of P-channel devices lead to higher switching losses.

Limitation: Hence, J2831 is best for low-to-moderate power and frequency applications.

Voltage and Drive

Challenge: J2831 requires a negative V_GS to turn on (since source is at the positive rail). The gate drive must swing to within a few volts of ground or below to fully turn it on.

Limitation: In high-side circuits above ~10–15 V, this can complicate gate-drive design (though simpler than boosting an N-channel gate).

Thermal Limit

Challenge: The small TO-92 package limits heat dissipation (power rating ~0.8–1 W at 25 °C).

Limitation: In continuous heavy load, the part must be derated or externally cooled.

Sourcing & Availability

Challenge: J2831 appears to be an older or less common part. Lead times can be long if not stocked. For example, one distributor listing shows large on-hand stock but a manufacturer lead time of 8–10 weeks, indicating potential long OEM wait. Supply chain issues (allocation, MOQs) can also be a concern for through-hole parts.

Packaging & Assembly

Challenge: Being through-hole (TO-92), J2831 is less compatible with modern automated surface-mount assembly. Designs aiming for miniaturization or high-volume PCBs may avoid TO-92 parts, preferring SMD packages.

Limitation: This can limit J2831’s use in new high-density products.

Competing Parts

Challenge: Because P-channel devices with similar specs (e.g. BS250 or SOT-23 MOSFETs) exist, parts like J2831 may fall out of favor.

Limitation: If sourcing J2831 becomes difficult, designers may need to re-specify to a newer part or footprint.

4. Costing

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Prototype vs. Production: In small prototype quantities (single or tens of units), the unit cost of J2831 can be relatively high due to overhead. For example, a similar part (BS250P) might cost on the order of ~$0.8–1.00 each in low qty. Packaging, test, and administrative costs (set-up, kitting) are spread over few parts, so per-unit cost is large. In contrast, bulk sourcing (1k–10k units or more) drives the die+packaging cost down to a few cents (e.g. ~$0.10–$0.20 each) plus modest mark-up. Note: packaging and testing can account for a significant fraction of the total cost; estimates suggest final assembly and test can be roughly 20–30% of a chip’s cost.

A rough cost breakdown might be:

Silicon die & wafer fab: A few cents per device (amortized over wafer).
Packaging & lead-frame: A few cents for epoxy, leadframe, and molding.
Assembly & Test: Tens of cents for bonding, lead trim, testing.
Mark-up & logistics: Variably add on distributor/handling fees.

As a heuristic, a prototype J2831 could run ~$1–2 each, while a 10k+ volume could be ~$0.1–0.2 each. (Actual pricing depends on supplier, date code, and demand.) Compliance (lead-free) and testing standards (AQL) may also affect cost.

As a heuristic, a prototype J2831 could run $\sim$ $1–2 each$, while a 10k+ volume could be $\sim$ $0.1–0.2 each$. (Actual pricing depends on supplier, date code, and demand.) Compliance (lead-free) and testing standards (AQL) may also affect cost.

In the context of sourcing, if one needs a lot of MOSFETs, J2831’s cost can add up versus using integrated solutions where a MOSFET might be part of a power management IC. However, for simple discrete switching, it remains a cost-effective solution, especially at volume.

The J2831’s straightforward nature keeps it cost-effective for adding discreet P-channel switching to a design without adding much to BOM cost. EstiSource can help buyers see the price breakpoints and suggest if alternative P-channel MOSFETs could offer cost savings for the required features (for instance, if an SMD package is acceptable, many SOT-23 P-channels offer better efficiency and lower cost for similar current ratings).

5. Properties and Characteristics

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Polarities

Properties: P-channel enhancement MOSFET. Source at positive rail. Turns on for V_GS negative.

Voltage Rating (V_DSS)

Properties: ≈ –45 V (max Drain–Source voltage).

Current Rating (I_D)

Properties: ≈ –0.18 A continuous (with higher pulsed current capability).

On-Resistance (R_DS(on))

Properties: ~14 Ω @ V_GS = –10 V (typical). High R_DS(on) is common for P-channel.

Gate Threshold (V_GS(th))

Properties: ~ –1.0 to –3.5 V (threshold for conduction).

Capacitances

Properties: Low input capacitance (~15 pF) and fast switching (~16 ns) make it adequate for simple switching.

Power Dissipation (P_D)

Properties: ~0.8 W at 25°C (TO-92 thermal limit).

Package

Properties: TO-92 (SOT-54); three through-hole leads on 2.54 mm spacing. Standard pinout (looking at flat face: Pin1=Source, Pin2=Gate, Pin3=Drain). Case is epoxy/plastic.

Temperature Range

Properties: Operation from –55°C up to +150°C junction.

Compliance

Properties: Rated Pb-free / RoHS compliant.

Other

Properties: As a Vishay part, it may follow Vishay Si–MOS family characteristics.

To summarize the salient properties: P-channel enhancement mode MOSFET in TO-92; -45V, -0.18A with ~14 Ohm R_DS(on); needs negative V_GS to turn on; ~0.8W power dissipation limit; operates from -55°C to +150°C. It is Pb-free and RoHS compliant.

6. Frequently Asked Questions

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Q1: What is the J2831 MOSFET used for?

J2831 is a P-channel enhancement-mode MOSFET in a TO-92 package. It’s used as a high-side switch or load switch in low-to-moderate power circuits. Typical uses include driving relays, lamps, and motors on the positive supply, battery protection, and logic-level load switching in DC–DC converters or power regulators.

Q2: What are the key specifications of J2831?

While a manufacturer datasheet would give exact numbers, a comparable device (BS250) has V_DS = –45 V, I_D ≈ –0.18 A, R_DS(on) ≈ 14 Ω at V_GS=–10V, and maximum power ≈0.83 W. Gate threshold is a few volts (–1 to –3.5V). Use these values as a reference; actual J2831 specs should be confirmed if a datasheet is found.

Q3: Which lead is Source, Gate, and Drain on the TO-92 package?

For a P-channel TO-92 like J2831, the pinout (flat face, leads down) is: Pin1 = Source, Pin2 = Gate, Pin3 = Drain. The source is the body of the P-channel MOSFET (positive side), the gate is the control terminal, and the drain is the output.

Q4: Is J2831 RoHS-compliant?

Yes. The vendor listing for J2831 indicates it is lead-free / RoHS compliant, meaning it meets environmental regulations on hazardous substances.

Q5: Can J2831 replace an N-channel MOSFET?

No. P-channel MOSFETs and N-channel MOSFETs are not interchangeable: they require opposite gate polarities and have different on-resistances. J2831 is for P-channel (source to +V), so it’s used on the high side. N-channel devices are used on the low side. If you need similar function on the low side or with higher efficiency, look for an N-channel part.

Q6: What are alternatives or replacements for J2831?

You can use any P-channel MOSFET with similar ratings in TO-92 or SOT-23 (SMD) packages. For example, Diodes Inc BS250 (TO-92) has similar –45V/–0.2A specs. Many OEMs offer P-channel transistors (Vishay, Diodes, ON Semiconductor, etc.). If TO-92 isn’t required, you can often substitute an SMD P-channel in a size that PCB can support. Just ensure V_DS, I_D, and R_DS(on) ratings match your needs.

Q7: How do I source J2831?

Check authorized distributors and brokers. EstiSource’s platform can aggregate real-time stock/lead-time info. For example, one distributor shows ~68k units available (for fast shipment) and ~8–10 week lead time from the manufacturer. If a part is on allocation or has long lead time, EstiSource can suggest alternates and handle RFQs to multiple suppliers. Always verify stock on multiple sources (some online listings may have outdated or placeholder pricing).

Q8: Can J2831 handle high-frequency switching?

It can switch reasonably fast for a discrete TO-92 part (some references note ~16 ns rise time for similar devices). However, its relatively high gate capacitance (tens of pF) and on-resistance mean it’s not ideal for very high-frequency, high-current PWM. Use it for modest switching speeds (kHz range) in small loads. For high-speed DC–DC converters, consider specialized logic-level MOSFETs.

These FAQs cover common points about using the J2831 P-Channel MOSFET. Overall, it’s a reliable component for its intended applications, but understanding its limitations (like high R_DS(on) and TO-92 package) is key for successful design.

J2831