STMicroelectronics TIP42C

Overview

TIP42C from STMicroelectronics is a complementary PNP silicon power transistor in TO-220 plastic package, designed for linear and switching power applications. It delivers 6 A continuous collector current, 100 V collector-emitter sustaining voltage (V_CEO(sus)), and 65 W total power dissipation at T_C = 25 °C, with h_FE grouped into R (15–28), O (24–44), or Y (42–75) for consistent gain matching in push-pull amplifier stages.

For engineers reviewing the TIP42C datasheet, TIP42C pinout, TIP42C application, or TIP42C equivalent, key selection considerations include its negative-polarity voltage/current ratings, TO-220 thermal resistance (R_thJC = 1.92 °C/W), h_FE grouping tolerance, and suitability for audio output stages requiring matched NPN/PNP pairs with TIP41C.

Technical Context

The TIP42C operates as a medium-power PNP bipolar junction transistor with base-island technology, optimized for both linear amplification and hard-switching duty. Its V_CE(sat) ≤ 1.5 V at I_C = 6 A / I_B = 0.6 A and V_BE(on) ≤ 2 V at same conditions define low-loss conduction behavior. The device supports pulse operation up to 10 A peak collector current with ≤2% duty cycle and ≤300 μs pulse width.

Thermal performance is defined by R_thJC = 1.92 °C/W and R_thJA = 62.5 °C/W, enabling direct heatsink mounting via the electrically connected tab. All voltage and current parameters are negative per PNP convention, including V_CBO = –100 V, V_CEO = –100 V, and I_C = –6 A.

Key Specifications

Pinout & Package

Package: TO-220 type H (plastic, single-ended heat sink mount). Tab is electrically connected to collector (C).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJD42C and BD912, TIP42C offers optimal balance of through-hole manufacturability, thermal performance (1.92 °C/W), and factory-gain binning-making it preferred for production audio amplifiers and industrial linear regulators where reliability and repeatability are critical.

Availability

TIP42C is available at Aetrix Electronics and suitable for audio power amplifiers, DC motor driver stages, and linear voltage regulators requiring stable component supply across OEM production cycles and repair spares programs.

Supply support for TIP42C 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, Switzerland, specializing in power management, analog, microcontrollers, and automotive ICs.

The TIP42C belongs to ST's legacy low-voltage complementary power transistor family, engineered specifically for cost-sensitive, medium-power linear and switching applications where robustness, thermal efficiency, and gain-matching with NPN counterparts are essential.

FAQ

Is the TIP42C pin-compatible with the TIP41C?

Yes, TIP42C and TIP41C share identical TO-220 pinout (Emitter–Base–Collector layout), enabling direct physical placement in complementary circuits. However, polarity reversal means all voltage and current polarities are inverted: TIP42C is PNP (negative V_CE, negative I_C), while TIP41C is NPN. Circuit biasing must be adjusted accordingly.

What does "h_FE grouping" mean for TIP42C?

h_FE grouping means ST pre-sorts TIP42C units into three discrete DC current gain bands-Group R (15–28), Group O (24–44), and Group Y (42–75)-measured at I_C = 0.3 A and V_CE = 4 V. This allows designers to select matched pairs with TIP41C for symmetrical push-pull amplifier biasing and reduced thermal drift.

Can TIP42C be used without a heatsink?

No. At 6 A continuous current and 65 W power dissipation, the TIP42C requires a heatsink to maintain junction temperature below 150 °C. With R_thJA = 62.5 °C/W, even at 1 W dissipation ambient temperature would rise over 60 °C above ambient-exceeding safe limits. The TO-220 tab must be mounted to a heatsink using thermal compound and mechanical fastener.

How does TIP42C differ from generic PNP transistors like 2N2907?

TIP42C is rated for 6 A continuous current and 65 W power dissipation-over ten times the capability of 2N2907 (0.6 A, 0.4 W). It features base-island construction for improved h_FE linearity and thermal robustness, TO-220 packaging for direct heatsinking, and factory gain grouping-making it suitable for power-stage applications where 2N2907 is limited to signal-level switching or bias networks.