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

STMicroelectronics TIP31C

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

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Part No.:: TIP31C

Manufacturer:: STMicroelectronics

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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Inventory:1,356

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Product details

Overview

TIP31C from STMicroelectronics is an NPN silicon power transistor in TO-220 package, rated for 100 V V_CEO, 3 A continuous collector current, and 40 W total dissipation at T_case = 25°C; designed for linear amplification and switching in audio output stages, DC motor drivers, and power supply regulators.

For engineers reviewing the TIP31C datasheet, TIP31C pinout, TIP31C application, or TIP31C equivalent, key selection criteria include V_CEO/V_CBO voltage rating, h_FE grouping (R/O/Y), safe operating area (SOA) limits, and thermal derating behavior under sustained conduction.

Technical Context

The TIP31C uses base-island technology to improve h_FE linearity and switching speed over legacy TIP31 variants. It operates with V_BE(on) = 1.8 V at I_C = 3 A and exhibits V_CE(sat) ≤ 1.2 V under same conditions, enabling efficient low-voltage saturation in Class AB audio and PWM-driven loads.

Its SOA is defined up to 100 V and 3 A with pulse constraints (300 ms, ≥1.5% duty cycle), and thermal resistance R_thJC supports heatsink-mounted operation with junction-to-case path optimized for TO-220 mounting geometry.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	100 V - maximum collector-emitter voltage before breakdown with base open; defines safe rail voltage headroom in linear regulator or amplifier designs
I_C (cont.)	3 A - continuous DC collector current limit at T_case = 25°C; sets baseline load drive capability without forced cooling
P_TOT	40 W - total power dissipation at case temperature of 25°C; determines minimum heatsink requirement for steady-state operation
h_FE (Group R)	25–50 - DC current gain range at I_C = 1 A, V_CE = 4 V; enables predictable biasing in fixed-gain emitter-follower or driver stages
V_CE(sat)	≤1.2 V @ I_C = 3 A, I_B = 375 mA - low saturation voltage reduces conduction loss in switching applications like relay drivers
T_J(max)	150 °C - maximum allowable junction temperature; constrains thermal design margin when ambient exceeds 70°C

Pinout & Package

TO-220 plastic package with vertical mounting orientation, metal tab connected to collector, and standardized 3-pin layout for mechanical stability and thermal transfer to heatsinks.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current sink terminal	Low-impedance return path; must be routed with low-inductance trace in high-speed switching
2 (Base)	Control input	Requires current-limited drive (max I_B = 1 A); base resistor selection critical for h_FE-dependent saturation
3 (Collector)	High-current output node	Internally bonded to metal tab; electrically and thermally coupled to heatsink mounting surface

Key Features

Feature	Design Value
Enhanced h_FE linearity	Improved gain consistency across I_C range enables stable Class AB bias in audio output stages without thermal runaway
Grouped h_FE bins (R/O/Y)	Pre-sorted DC gain ranges allow matched-pair selection for differential amplifiers or push-pull drivers
High switching speed	Reduced storage time vs. standard TIP31 supports >10 kHz PWM operation in DC-DC and motor control
ECOPACK® compliance	Lead-free second-level interconnect meets RoHS and JEDEC JESD97 marking requirements for industrial PCB assembly

Applications

Audio Power Amplifier

DC Motor Driver

Use Scenario: Output stage in 10–20 W Class AB audio amplifier driving 4–8 Ω speakers.

IC Role / Device Role / Timing Role: NPN power transistor delivering peak current up to 3 A into reactive load with minimal crossover distortion.

Use Value: V_CEO = 100 V provides sufficient rail margin for ±35 V supplies; h_FE linearity ensures stable quiescent current setting.

Use Scenario: H-bridge half-bridge switch controlling bidirectional 12–24 V DC motors up to 2 A average current.

IC Role / Device Role / Timing Role: High-side or low-side switching element handling pulsed load current with fast turn-on/turn-off.

Use Value: V_CE(sat) ≤ 1.2 V minimizes I²R loss during conduction; SOA supports 300 ms stall current pulses.

Linear Voltage Regulator

Switching Power Supply

Use Scenario: Pass transistor in adjustable 3–30 V, 1–2 A linear regulator using LM317 feedback network.

IC Role / Device Role / Timing Role: Series pass element dissipating excess voltage as heat while maintaining regulated output.

Use Value: P_TOT = 40 W allows 10 V × 2 A = 20 W dissipation with adequate heatsinking; T_J(max) = 150 °C sets thermal shutdown threshold.

Use Scenario: Main switch in 50–100 kHz flyback or forward converter delivering up to 30 W output.

IC Role / Device Role / Timing Role: Primary-side switching transistor turning on/off under PWM control to regulate energy transfer.

Use Value: V_CBO = 100 V accommodates reflected primary voltage spikes; fast switching reduces transition losses at 100 kHz.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MJE13003	V_CEO = 400 V, I_C = 1.5 A, h_FE = 8–40 - higher voltage rating but lower current and gain	Better suited for high-voltage, low-current SMPS primary switches; not drop-in for 3 A audio output	Select when V_in > 200 V DC and I_load < 1.5 A; verify SOA at target switching frequency
BD139	V_CEO = 80 V, I_C = 1.5 A, P_TOT = 12.5 W - lower voltage, current, and power than TIP31C	Targeted at low-power audio preamps and signal switching; insufficient for 3 A motor drive	Use only in sub-10 W linear stages or low-duty-cycle switching where thermal budget is tight

Compared with MJE13003 and BD139, the TIP31C uniquely balances 100 V breakdown, 3 A current, and 40 W dissipation-making it optimal for mid-power linear and switching roles where both voltage headroom and thermal capacity are required.

Availability

TIP31C is available at Aetrix Electronics and suitable for audio amplifiers, DC motor controllers, and linear voltage regulators requiring stable component supply with consistent h_FE binning and TO-220 mechanical compatibility.

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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing analog, power, MCU, and sensor solutions for industrial, automotive, and consumer markets.

The TIP31C belongs to ST's legacy power bipolar transistor family, engineered specifically for cost-sensitive, medium-power linear and switching applications where robustness, thermal reliability, and gain consistency are prioritized over ultra-high-frequency performance.

FAQ

What is the difference between TIP31C and TIP31A/B?

The TIP31C has higher voltage ratings (V_CEO = V_VCBO = 100 V) versus TIP31A (60 V) and TIP31B (80 V). It also features improved h_FE linearity and grouped gain bins (R/O/Y), making it more suitable for precision biasing in audio and regulated power applications.

Is the metal tab on the TO-220 package electrically connected?

Yes-the metal tab is internally connected to the collector terminal. When mounted to a heatsink, the heatsink becomes part of the collector circuit; electrical isolation (e.g., mica washer + shoulder washer) is required unless the heatsink is floating or referenced to collector potential.

Can TIP31C replace TIP32C in a circuit?

No-TIP31C is NPN and TIP32C is its complementary PNP counterpart. They cannot substitute directly due to opposite polarity, different biasing requirements, and reversed current flow direction; they are intended for use together in push-pull or complementary symmetry configurations.

What does "Group R/O/Y" mean in the datasheet?

It indicates factory-sorted h_FE bins: Group R (25–50), Group O (10–24), and Group Y (20–44), all measured at I_C = 1 A and V_CE = 4 V. This allows designers to select matched devices for differential pairs or ensure minimum gain in critical bias networks.

TIP31C Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-220-3

Packaging:: Tube

Product Status:: Active

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:: -

Operating Temperature:: 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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