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

STMicroelectronics TIP42A

Name: TIP42A
Brand: STMicroelectronics
SKU: TIP42A
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: TIP42A

Manufacturer:: STMicroelectronics

Category:: Single Bipolar Transistors

Package:: TO-220-3

Datasheet:: TIP42A.pdf

Description:: TRANS PNP 60V 6A TO-220

Quantity:: RFQ Add To RFQ list

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Inventory:1,789

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Product details

Overview

TIP42A from STMicroelectronics is a complementary PNP silicon power transistor in TO-220 package, rated for 60 V V_CEO, 6 A continuous collector current, and 65 W total dissipation at T_case = 25°C; it serves as the PNP counterpart to TIP41A in push-pull audio amplifier stages and linear power regulator circuits.

For engineers reviewing the TIP42A datasheet, TIP42A pinout, TIP42A application, or TIP42A equivalent, key selection criteria include its verified V_CE(sat) ≤ 1.5 V at I_C = 6 A / I_B = 0.6 A, h_FE ≥ 30 at I_C = 0.3 A, and guaranteed −65 °C to +150 °C operating junction temperature range.

Technical Context

The TIP42A operates as a medium-power PNP bipolar junction transistor with base-emitter forward bias enabling controlled collector current flow; its DC current gain (h_FE) is specified at two operating points-30–75 at I_C = 0.3 A and 15–? at I_C = 3 A-supporting both linear amplification and switching functions.

It features a maximum collector-emitter sustaining voltage (V_CEO(sus)) of −60 V under I_C = 30 mA, and exhibits V_BE(on) = −2 V at I_C = 6 A and V_CE = −4 V, confirming robust turn-on behavior in high-current drive applications.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	−60 V: Maximum reverse-biased collector-emitter voltage before breakdown in common-emitter configuration.
I_C (cont.)	−6 A: Continuous collector current rating defining safe DC conduction capability in linear or switching mode.
P_TOT	65 W at T_case = 25°C: Thermal power limit requiring heatsinking for sustained operation above ambient.
V_CE(sat)	≤ −1.5 V at I_C = −6 A, I_B = −0.6 A: Confirmed low-saturation voltage enabling efficient switching with minimal conduction loss.
h_FE	30–75 at I_C = −0.3 A, V_CE = −4 V: Verified DC current gain range supporting predictable base drive design.
T_J(max)	+150 °C: Maximum allowable junction temperature, setting thermal design margin for reliability-critical deployments.

Pinout & Package

TO-220 package: 3-terminal plastic case with metal tab (collector) electrically connected to pin 2; standardized mounting hole and heat-transfer surface for mechanical attachment to heatsinks.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current exit path for PNP device	Connected to higher potential rail in common-emitter switch or amplifier; polarity-sensitive for correct biasing.
2 (Collector)	Main current sink terminal	Internally bonded to metal tab; must be electrically isolated from heatsink unless circuit design permits common connection.
3 (Base)	Control input for minority-carrier injection	Receives negative base current to turn on; requires series resistor to limit I_B ≤ −3 mA per absolute max rating.

Key Features

Feature	Design Value
Complementary PNP pairing	Matched electrical characteristics with TIP41A enable symmetrical push-pull stage design without gain or timing mismatch.
Enhanced h_FE linearity	Specified h_FE across I_C = 0.3 A to 3 A supports stable biasing in Class AB audio output stages.
High switching speed	Documented BT(ON) time and resistive-load switching times confirm suitability for <100 kHz PWM control in linear-regulator bypass or motor drive.
ECOPACK® compliance	Lead-free second-level interconnect meets RoHS requirements without derating or solder-process modification.

Applications

Audio Power Amplifier Output Stage

Linear Voltage Regulator Pass Element

Use Scenario: Used in complementary emitter-follower output stage of 20–50 W discrete audio amplifiers driving 4–8 Ω speakers.

IC Role / Device Role / Timing Role: PNP power transistor delivering negative half-cycle current while maintaining low V_CE(sat) and thermal stability.

Use Value: Verified h_FE ≥ 30 at I_C = 0.3 A ensures sufficient current gain for driver-stage interfacing without excessive base drive power.

Use Scenario: Serves as pass transistor in adjustable linear regulators (e.g., LM317-based) supplying up to 6 A load current.

IC Role / Device Role / Timing Role: Regulates output voltage by dissipating excess power as heat; operates in active region with fixed V_BE ≈ −2 V.

Use Value: 65 W power dissipation rating enables stable operation at full load with appropriate heatsinking and ambient ≤ 50 °C.

DC Motor H-Bridge Low-Side Switch

Relay/LED Load Driver

Use Scenario: Configured as low-side switch in unidirectional DC motor control circuits with freewheeling diode protection.

IC Role / Device Role / Timing Role: PNP configured in common-emitter with emitter tied to supply; collector drives motor return path.

Use Value: −60 V V_CEO rating provides margin against inductive kickback spikes up to −48 V in 24 V systems.

Use Scenario: Drives high-current relays (≥ 2 A coil) or LED arrays (e.g., automotive lighting) from microcontroller GPIO.

IC Role / Device Role / Timing Role: Acts as saturated switch turning on/off loads referenced to positive rail via emitter connection.

Use Value: −1.5 V V_CE(sat) at −6 A minimizes power loss and self-heating during continuous on-state operation.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MJE15034	Higher V_CEO (−120 V), lower I_C (−4 A), TO-218 package	Better suited for high-voltage industrial controls; less ideal for high-current audio due to reduced I_C rating	Select when >80 V breakdown margin required and heatsink space allows larger TO-218 footprint
BD912	Lower V_CEO (−80 V), same I_C (−6 A), TO-126 package	Limited power dissipation (40 W) restricts use in sustained high-power linear regulation	Prefer for compact PCB layouts where 40 W thermal budget suffices and TO-126 mounting is preferred

Compared with MJE15034 and BD912, the TIP42A uniquely balances 60 V/6 A/65 W ratings in TO-220-a widely supported, cost-effective form factor for mid-power analog and switching designs requiring proven thermal and gain consistency.

Availability

TIP42A is available at Aetrix Electronics and suitable for audio amplifier output stages, linear voltage regulator pass elements, DC motor control circuits, and relay/LED load drivers requiring stable component supply across production lifecycles.

Supply support for TIP42A 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 TIP42A belongs to ST's legacy silicon power transistor family, engineered specifically for cost-sensitive, medium-power linear and switching applications where reliability, thermal performance, and complementary pairing are essential.

FAQ

Is the TIP42A pin-compatible with the TIP42C?

No. The TIP42A has V_CEO = −60 V and h_FE min = 30 at I_C = 0.3 A, whereas the TIP42C offers V_CEO = −100 V and h_FE min = 30 at I_C = 1.5 A. Their different voltage and gain specifications mean direct substitution may compromise circuit safety or bias stability without redesign.

Can the TIP42A be used in place of an NPN transistor like the TIP41A?

No-it is a PNP device with opposite polarity: emitter connects to higher potential, collector to lower. Swapping it for a TIP41A (NPN) would reverse bias conditions and prevent proper conduction. It is only interchangeable in complementary roles, not as a direct NPN replacement.

What is the recommended heatsink thermal resistance for continuous 6 A operation?

At I_C = −6 A and V_CE ≈ −1.5 V, power dissipation is ~9 W; assuming T_J(max) = 150 °C and T_amb = 50 °C, R_θJA must be ≤ 11.1 °C/W. With R_θJC = 1.5 °C/W (per datasheet), a heatsink with R_θSA ≤ 9.6 °C/W is required for safe continuous operation.

Does the TIP42A require a base current limiting resistor in switching applications?

Yes. Absolute maximum I_B is −3 mA. For reliable saturation at I_C = −6 A (h_FE ≥ 30), minimum I_B = −200 mA is needed-but this exceeds rating. Therefore, forced β ≈ 10 is used: I_B ≈ −600 mA, requiring a resistor sized to drop available drive voltage minus V_BE(on) ≈ −2 V.

TIP42A Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-220-3

Packaging:: Tube

Product Status:: Active

Transistor Type:: PNP

Current - Collector (Ic) (Max):: 6 A

Voltage - Collector Emitter Breakdown (Max):: 60 V

Vce Saturation (Max) @ Ib, Ic:: 1.5V @ 600mA, 6A

Current - Collector Cutoff (Max):: 700µA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 15 @ 3A, 4V

Power - Max:: 2 W

Frequency - Transition:: -

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220

TIP42A FAQ

1.How can I place an order for TIP42A through Aetrix?

Please submit a Request for Quotation (RFQ) for TIP42A 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 TIP42A reliable?

The price and inventory of TIP42A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TIP42A is usually 5 days.

3.What payment methods are accepted for TIP42A?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TIP42A transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for TIP42A?

TIP42A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your TIP42A 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 TIP42A?

For technical support, including TIP42A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TIP42A requirements.

6.How does Aetrix verify that TIP42A is sourced from the original manufacturer or authorized distributors?

All TIP42A 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 TIP42A meets industry standards.

7.What is the process for return or replacement of TIP42A?

All TIP42A units undergo pre-shipment inspection (PSI). If there is an issue with TIP42A, 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 TIP42A part is unused and in its original packaging.

Return procedure for TIP42A:

1.Submit a request within 90 days.

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

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