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onsemi TIP31B
- Part No.:
- TIP31B
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-220-3
- Datasheet:
-
TIP31B.pdf
- Description:
- TRANS NPN 80V 3A TO-220-3
- Quantity:
- Payment:
- Shipping:
Inventory:8,513
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Product details
Overview
TIP31B from onsemi is an NPN silicon power transistor in TO-220AB package, rated for 80 VCEO, 3.0 A continuous collector current, and 40 W total power dissipation at TC = 25°C. It delivers VCE(sat) ≤ 1.2 V at IC = 3.0 A and fT ≥ 3.0 MHz, making it suitable for medium-power linear amplifiers and DC/DC switching circuits in industrial power supplies.
For engineers reviewing the TIP31B datasheet, pinout, applications, or equivalent options, key selection criteria include its 80 V VCEO(sus), thermal resistance RθJC = 3.125 °C/W, unclamped inductive energy rating of 32 mJ, and complementary pairing with TIP32B for push-pull output stages.
Technical Context
The TIP31B operates as a general-purpose bipolar junction transistor with fixed-base drive architecture and no integrated protection circuitry. Its safe operating area (SOA) is defined by secondary breakdown limits up to 100 µs pulses and thermal constraints governed by RθJC = 3.125 °C/W and RθJA = 62.5 °C/W.
It exhibits DC current gain hFE ≥ 25 at IC = 1.0 A and ≥ 10 at IC = 3.0 A, with VBE(on) ≈ 1.8 V and Ceb/Ccb capacitance values optimized for <3 MHz small-signal operation - confirming suitability for audio-frequency amplification and low-speed switching below 100 kHz.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO(sus) | 80 Vdc minimum - supports rail voltages up to 64 V in linear regulators or 56 V in switching converters with 20% safety margin |
| IC (continuous) | 3.0 Adc - enables 24 W load driving capability at 8 V drop across collector-emitter in Class-A amplifier stage |
| VCE(sat) | ≤1.2 Vdc at IC = 3.0 A, IB = 375 mA - limits conduction loss to ≤3.6 W in saturated switch mode |
| fT | ≥3.0 MHz at IC = 500 mAdc - sufficient for audio-band amplification and PWM control up to ~100 kHz |
| RθJC | 3.125 °C/W - allows 40 W power dissipation with ≤125°C junction rise above case temperature |
| Unclamped energy | 32 mJ - defines maximum inductive kickback energy survivable without snubber in relay or solenoid drivers |
| PD @ TA | 2.0 W at 25°C ambient - sets heatsink requirement threshold for natural-convection operation |
Pinout & Package
Package: TO-220AB (Case 221A-09), 4-lead plastic power package with two collector pins (1 and 4) for enhanced thermal and current handling. Mounting tab is electrically connected to collector.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Base) | Current-controlled input terminal | Receives base drive current to bias transistor into active or saturation region; requires external series resistor for current limiting |
| 2 (Collector) | Main high-current output terminal | Connected to positive supply rail in common-emitter configuration; shares internal connection with Pin 4 |
| 3 (Emitter) | Reference and return path terminal | Serves as current sink node; tied to ground or negative rail; voltage drop determines emitter-follower output compliance |
| 4 (Collector) | Secondary collector connection | Redundant collector terminal for improved thermal spreading and parallel PCB trace routing; same potential as Pin 2 |
Key Features
| Feature | Design Value |
|---|---|
| Complementary PNP pairing | Designed for direct use with TIP32B in push-pull, quasi-complementary, or H-bridge output stages without level-shifting |
| High ruggedness rating | 32 mJ unclamped inductive energy tolerance enables reliable operation in relay/solenoid driver circuits without added flyback diodes |
| Thermal efficiency | RθJC = 3.125 °C/W allows full 40 W power dissipation with modest heatsinking - reduces thermal interface material and fin volume requirements |
| DC gain stability | hFE ≥ 10 at IC = 3.0 A ensures predictable base drive sizing across production lots and temperature range (–65°C to +150°C) |
| TO-220AB mechanical robustness | 4-pin layout with dual collector leads improves solder joint reliability and current sharing versus standard 3-pin TO-220 variants |
Applications
| Linear Power Amplifier | DC Motor Driver |
|---|---|
Use Scenario: Medium-power audio output stage delivering 15–20 W into 4 Ω or 8 Ω loads with minimal external components. IC Role / Device Role / Timing Role: NPN power transistor operating in Class-AB linear mode, biased via resistive divider and thermally stabilized with emitter degeneration resistor. Use Value: Delivers low-distortion amplification with VCE(sat) ≤ 1.2 V ensuring >85% efficiency in quiescent state and fT ≥ 3 MHz supporting full audio bandwidth. |
Use Scenario: Unidirectional 24 V DC brushed motor control in industrial actuators, with PWM frequency ≤ 20 kHz. IC Role / Device Role / Timing Role: High-current switching element in low-side configuration, driven by microcontroller GPIO through Darlington or MOSFET gate driver. Use Value: Withstands 32 mJ inductive energy during turn-off, eliminating need for external snubbers; 80 V rating accommodates 24 V supply with 200% transient margin. |
| Switching Regulator Pass Element | Relay/Solenoid Interface |
Use Scenario: Series pass transistor in adjustable linear regulator supplying 1.2–30 V at up to 2.5 A for test equipment or analog subsystems. IC Role / Device Role / Timing Role: Voltage-controlled current source regulating output by dissipating excess input-output differential voltage. Use Value: 40 W power rating and RθJC = 3.125 °C/W enable stable regulation under worst-case dropout (e.g., 12 V in → 3 V out @ 2.5 A = 22.5 W dissipation). |
Use Scenario: Driving 12 V or 24 V electromagnetic relays (100–500 mW coils) or 12 V solenoids (1–3 W) in PLC I/O modules. IC Role / Device Role / Timing Role: Saturated switch controlling coil current flow, with base driven by optocoupler or logic-level signal. Use Value: 3.0 A IC rating exceeds typical solenoid surge currents; 32 mJ energy rating absorbs back-EMF without clamping diode in space-constrained designs. |
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 | Higher VCEO = 400 V, lower IC = 1.5 A, TO-126 package, RθJC = 8 °C/W | Better for high-voltage flyback or SMPS primary side; unsuitable for 3 A continuous loads | Select when >100 V blocking is required and current demand is ≤1.5 A; not drop-in due to package and thermal mismatch |
| TIP31C | Higher VCEO(sus) = 100 V, identical TO-220AB package and pinout, same thermal specs | Direct upgrade path for systems requiring >80 V rail tolerance or higher transient immunity | Drop-in replacement if board layout supports 100 V rating; otherwise retain TIP31B for cost-sensitive 60–80 V applications |
Compared with MJE13003, TIP31B offers 2× higher continuous current and 2.5× better thermal resistance but 25% lower voltage rating; compared with TIP31C, it trades 20 V headroom for lower unit cost while maintaining identical footprint, drive requirements, and SOA behavior below 80 V.
Availability
TIP31B is available at Aetrix Electronics and suitable for industrial motor controls, linear power supplies, and electromagnetic actuator interfaces requiring stable component supply and long-term manufacturing continuity.
Supply support for TIP31B 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 management, analog, sensor, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.
The TIP31B belongs to onsemi's legacy silicon power transistor family designed for cost-sensitive, medium-power linear and switching applications where ruggedness, thermal performance, and complementary PNP pairing are critical.
FAQ
What is the maximum collector-emitter sustaining voltage for TIP31B?
The TIP31B has a minimum VCEO(sus) of 80 Vdc, verified per datasheet Figure 5 and "OFF CHARACTERISTICS" table. This rating applies under specified test conditions (IC = 30 mAdc, IB = 0) and defines the highest DC voltage the device can block in open-base configuration before entering avalanche breakdown. Designers should maintain at least 20% derating margin for reliability in real-world transients.
Can TIP31B be used as a direct replacement for TIP31A in existing designs?
No - TIP31B is not a direct replacement for TIP31A due to its higher 80 V VCEO(sus) versus 60 V for TIP31A. While both share TO-220AB package and pinout, substituting TIP31B may alter bias point stability and SOA margins in circuits designed around TIP31A's lower voltage rating. Verify safe operating area curves and transient voltage profiles before interchange.
What is the thermal resistance from junction to case for TIP31B?
The TIP31B has a maximum thermal resistance RθJC of 3.125 °C/W, as specified in the "THERMAL CHARACTERISTICS" table. This value reflects heat transfer efficiency from the silicon die to the mounting surface (collector tab) under standardized test conditions. It enables calculation of junction temperature rise: TJ = TC + (PD × RθJC), critical for reliability validation.
Does TIP31B require a heatsink in all applications?
TIP31B requires a heatsink whenever power dissipation exceeds 2.0 W at ambient temperature (per PD @ TA = 25°C rating). At full 40 W dissipation, a heatsink capable of maintaining case temperature ≤ 25°C is mandatory. For intermittent loads, transient thermal impedance data (Figure 4) must be used to assess short-duration capability without heatsinking.
How does the dual-collector pin configuration of TIP31B improve performance?
The TO-220AB package of TIP31B features two collector pins (1 and 4) internally bonded to the same die region. This design lowers effective lead inductance and spreads current across two parallel paths, reducing localized heating and improving solder joint reliability. It also simplifies PCB layout for high-current traces without compromising thermal path integrity to the heatsink-mounting tab.
TIP31B Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-220-3
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Transistor Type:
- NPN
- Current - Collector (Ic) (Max):
- 3 A
- Voltage - Collector Emitter Breakdown (Max):
- 80 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:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-220-3
TIP31B FAQ
1.How can I place an order for TIP31B through Aetrix?
Please submit a Request for Quotation (RFQ) for TIP31B 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 TIP31B reliable?
The price and inventory of TIP31B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TIP31B is usually 5 days.
3.What payment methods are accepted for TIP31B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TIP31B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TIP31B?
TIP31B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TIP31B 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 TIP31B?
For technical support, including TIP31B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TIP31B requirements.
6.How does Aetrix verify that TIP31B is sourced from the original manufacturer or authorized distributors?
All TIP31B 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 TIP31B meets industry standards.
7.What is the process for return or replacement of TIP31B?
All TIP31B units undergo pre-shipment inspection (PSI). If there is an issue with TIP31B, 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 TIP31B part is unused and in its original packaging.
Return procedure for TIP31B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TIP31B Tags
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