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Home > Products > Discrete Semiconductor Products > Transistors > Bipolar (BJT) > Single Bipolar Transistors

onsemi TIP31C

Name: TIP31C
Brand: onsemi
SKU: TIP31C
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: TIP31C

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-220-3

Datasheet:: TIP31C.pdf

Description:: TRANS NPN 100V 3A TO-220

Quantity:: RFQ Add To RFQ list

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Product details

Overview

TIP31C from onsemi is an NPN silicon power transistor in TO−220 package, rated for 100 V_CEO, 3.0 A continuous collector current, and 40 W power dissipation at T_C = 25°C. It delivers h_FE ≥10 at I_C = 3.0 A, V_CE = 4.0 V, and V_CE(sat) ≤ 1.2 V under same conditions - enabling use in medium-power linear amplifiers and switching circuits such as DC motor drivers and relay interfaces.

For engineers reviewing the TIP31C datasheet, pinout, applications, or equivalent options, key selection criteria include its 100 V blocking capability, thermal resistance R_JC = 3.125 °C/W, unclamped inductive energy rating of 32 mJ, and Pb-free TO−220−3 package with verified base-collector-emitter terminal mapping.

Technical Context

The TIP31C operates as a general-purpose bipolar junction transistor optimized for linear amplification and hard-switching applications. Its design supports DC current gain (h_FE) of 10–50 across 1.0–3.0 A collector loads, with f_T = 3.0 MHz ensuring usable bandwidth in audio-frequency amplifiers and PWM-driven loads.

Thermal performance is defined by R_JC = 3.125 °C/W and R_JA = 62.5 °C/W, requiring heatsinking for sustained >2 W dissipation. Safe operating area (SOA) curves confirm second-breakdown immunity up to 100 V and 3 A for single-pulse operation at T_J ≤ 150°C.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	100 Vdc - maximum collector-emitter voltage before breakdown; enables use in 72 VDC bus and 100 V peak AC line applications.
I_C (continuous)	3.0 Adc - continuous collector current limit; supports 2.5 A load drive with 15% margin for thermal derating.
P_D @ T_C = 25°C	40 W - total power dissipation with case temperature maintained at 25°C; requires mechanical heatsink for >2 W ambient operation.
h_FE	10–50 - DC current gain range at I_C = 1.0–3.0 A; ensures stable biasing in Class-A amplifier stages and predictable base drive sizing.
V_CE(sat)	≤1.2 Vdc at I_C = 3.0 A, I_B = 375 mA - low saturation voltage minimizes conduction loss in switching mode, e.g., <0.9 W loss at full load.
f_T	3.0 MHz - current-gain bandwidth product; sufficient for audio amplification (≤20 kHz) and PWM switching up to ~100 kHz with gain margin.
E (unclamped)	32 mJ - energy handling under inductive turn-off (I_C = 1.8 A, L = 20 mH); supports snubberless relay/motor coil switching at 10 Hz PRF.

Pinout & Package

Package: TO−220−3 (Case 221A), 10.10 × 15.12 × 4.45 mm, 2.54 mm lead pitch, Pb-free, RoHS compliant. Mounting tab is electrically connected to collector.

Pin/Terminal	Circuit Role	Design Meaning
1	Base	Current-controlled input node; requires ≥375 mA base drive for full 3 A saturation; sensitive to ESD per IEC 61000-4-2 Level 2.
2 & 4	Collector	High-current output node tied to heatsink tab; must be isolated from chassis unless circuit ground reference permits.
3	Emitter	Common return path for collector current; connects to system ground or load return; low-impedance path critical for stability in high-gain stages.

Key Features

Feature	Design Value
High V_CEO rating	100 V enables direct interface with industrial 48–72 VDC supplies without series voltage clamping.
Robust SOA	Second-breakdown limited only above 100 V/3 A pulse envelope - supports reliable inductive load switching without external protection.
Low R_JC	3.125 °C/W allows efficient heat transfer to heatsink; achieves T_J = 125°C at P_D = 24 W with 20°C/W heatsink.
Pb-free & RoHS	Compliant with EU Directive 2011/65/EU; compatible with lead-free reflow profiles (peak 260°C, 10 s).
TO−220 mechanical standardization	Universal footprint and mounting hole pattern simplifies board reuse across TIP31x/TIP32x family variants.

Applications

DC Motor Driver	Linear Audio Amplifier
Use Scenario: Driving 24–48 V brushed DC motors in industrial actuators with PWM control at ≤20 kHz. IC Role / Device Role / Timing Role: NPN power switch controlling motor current path between supply rail and ground. Use Value: 100 V rating accommodates back-EMF spikes up to 80 V; 32 mJ unclamped energy rating eliminates need for flyback diode in low-duty-cycle applications.	Use Scenario: Output stage in 5–10 W Class-A audio amplifiers for public address systems. IC Role / Device Role / Timing Role: Single-ended voltage-to-current transducer delivering low-distortion analog output. Use Value: h_FE ≥10 at 3 A ensures stable quiescent bias; f_T = 3 MHz provides >150× gain-bandwidth margin at 20 kHz.
Relay Driver	Power Supply Pass Transistor
Use Scenario: Solid-state replacement for electromechanical relays in PLC I/O modules switching 24 VDC solenoids. IC Role / Device Role / Timing Role: High-current switch interfacing microcontroller GPIO to inductive load. Use Value: V_CE(sat) ≤1.2 V limits power loss to <0.9 W at 3 A, reducing thermal load vs. MOSFET alternatives with higher gate charge.	Use Scenario: Series pass element in adjustable linear regulators delivering up to 2.5 A at ≤30 V output. IC Role / Device Role / Timing Role: Voltage-controlled current source regulating output via feedback loop. Use Value: 40 W dissipation capacity supports 5 V dropout at 2.5 A; R_JC = 3.125 °C/W enables compact heatsink design.

DC Motor Driver

Linear Audio Amplifier

Use Scenario: Driving 24–48 V brushed DC motors in industrial actuators with PWM control at ≤20 kHz.

IC Role / Device Role / Timing Role: NPN power switch controlling motor current path between supply rail and ground.

Use Value: 100 V rating accommodates back-EMF spikes up to 80 V; 32 mJ unclamped energy rating eliminates need for flyback diode in low-duty-cycle applications.

Use Scenario: Output stage in 5–10 W Class-A audio amplifiers for public address systems.

IC Role / Device Role / Timing Role: Single-ended voltage-to-current transducer delivering low-distortion analog output.

Use Value: h_FE ≥10 at 3 A ensures stable quiescent bias; f_T = 3 MHz provides >150× gain-bandwidth margin at 20 kHz.

Relay Driver

Power Supply Pass Transistor

Use Scenario: Solid-state replacement for electromechanical relays in PLC I/O modules switching 24 VDC solenoids.

IC Role / Device Role / Timing Role: High-current switch interfacing microcontroller GPIO to inductive load.

Use Value: V_CE(sat) ≤1.2 V limits power loss to <0.9 W at 3 A, reducing thermal load vs. MOSFET alternatives with higher gate charge.

Use Scenario: Series pass element in adjustable linear regulators delivering up to 2.5 A at ≤30 V output.

IC Role / Device Role / Timing Role: Voltage-controlled current source regulating output via feedback loop.

Use Value: 40 W dissipation capacity supports 5 V dropout at 2.5 A; R_JC = 3.125 °C/W enables compact heatsink design.

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN power transistor applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MJD31C	Same V_CEO = 100 V, but SOT-223 package (R_JA = 125 °C/W); I_C = 3.0 A, P_D = 1.5 W @ T_A.	Not suitable for >1.5 W continuous dissipation without forced air; limited to low-power switching or low-duty-cycle use.	Select MJD31C only when board space is constrained and thermal load remains below 1 W.
TIP31B	V_CEO = 80 V, identical TO−220 package, same pinout, R_JC = 3.125 °C/W, P_D = 40 W.	Lower voltage rating restricts use to ≤60 V systems; otherwise functionally interchangeable in existing layouts.	Choose TIP31B where 80 V margin suffices and cost optimization is prioritized over 100 V headroom.

Compared with TIP31C, MJD31C trades thermal capability for footprint reduction, while TIP31B retains identical packaging and thermal behavior but reduces voltage safety margin by 20 V - making TIP31C the sole option for 72–100 VDC applications demanding full 40 W dissipation.

Availability

TIP31C is available at Aetrix Electronics and suitable for DC motor control, linear amplifier output stages, relay driver circuits, and linear regulator pass elements requiring stable component supply and long-term industrial availability.

Supply support for TIP31C includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The TIP31C belongs to onsemi's legacy plastic power transistor family designed for cost-sensitive, medium-power linear and switching applications where robustness, thermal reliability, and standardized TO−220 compatibility are essential.

FAQ

What is the maximum continuous collector current rating for the TIP31C?

The TIP31C has a maximum continuous collector current (I_C) rating of 3.0 A at T_C = 25°C. This value decreases with rising case temperature - derating is 0.32 W/°C above 25°C for power dissipation, and corresponding current reduction follows thermal constraints. At T_C = 75°C, usable I_C drops to approximately 2.2 A to maintain safe junction temperature.

Does the TIP31C have a built-in base-emitter resistor or protection diode?

No, the TIP31C is a standard NPN bipolar junction transistor with no integrated base-emitter resistor or protection diode. External base resistors must be sized to deliver ≥375 mA base current for full saturation at 3.0 A collector load, and external flyback diodes are required for inductive loads unless operating within the documented 32 mJ unclamped energy limit.

Can the TIP31C be used as a direct replacement for the TIP31A or TIP31B in an existing design?

The TIP31C shares identical TO−220 package, pinout, and thermal characteristics with TIP31A and TIP31B, but offers higher V_CEO (100 V vs. 40 V and 80 V). It can replace them in designs where voltage margin is sufficient, though over-specifying V_CEO does not degrade performance - only cost and availability differ across the TIP31x series.

What is the safe operating area (SOA) limitation for the TIP31C at DC operation?

At DC (single-pulse, t → ∞), the TIP31C's SOA is bounded by thermal limits: maximum power dissipation is 40 W at T_C = 25°C, decreasing linearly with case temperature. Second breakdown does not constrain DC operation - the 100 V/3 A corner point is thermally limited, not secondary-breakdown limited, per Figure 5 of the onsemi datasheet.

Is the TIP31C RoHS compliant and lead-free?

Yes, the TIP31C is marked with suffix "G" indicating Pb-free construction and full compliance with EU RoHS Directive 2011/65/EU. Its TO−220 package uses lead-free matte tin plating and meets JEDEC J-STD-020 moisture sensitivity level (MSL) 1 requirements for surface-mount assembly.

TIP31C Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-220-3

Packaging:: Tube

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 3 A

Voltage - Collector Emitter Breakdown (Max):: 100 V

Vce Saturation (Max) @ Ib, Ic:: 1.2V @ 375mA, 3A

Current - Collector Cutoff (Max):: 300µA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 10 @ 3A, 4V

Power - Max:: 2 W

Frequency - Transition:: 3MHz

Operating Temperature:: -65°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220

TIP31C FAQ

1.How can I place an order for TIP31C through Aetrix?

Please submit a Request for Quotation (RFQ) for TIP31C on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for TIP31C reliable?

The price and inventory of TIP31C are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TIP31C is usually 5 days.

3.What payment methods are accepted for TIP31C?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TIP31C transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for TIP31C?

TIP31C orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your TIP31C order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for TIP31C?

For technical support, including TIP31C datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TIP31C requirements.

6.How does Aetrix verify that TIP31C is sourced from the original manufacturer or authorized distributors?

All TIP31C products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that TIP31C meets industry standards.

7.What is the process for return or replacement of TIP31C?

All TIP31C units undergo pre-shipment inspection (PSI). If there is an issue with TIP31C, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The TIP31C part is unused and in its original packaging.

Return procedure for TIP31C:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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