STMicroelectronics TIP42CN

Overview

TIP42CN from STMicroelectronics is a complementary PNP silicon power transistor in TO-220 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 - used in audio amplifier output stages and DC power supply regulation circuits.

For engineers reviewing the TIP42CN datasheet, TIP42CN pinout, TIP42CN application, or TIP42CN equivalent, key selection criteria include verified PNP polarity, h_FE grouping (R/O/Y), V_CE(sat) ≤ 1.5 V at I_C = 6 A, thermal derating behavior, and TO-220 mechanical compatibility with heatsink mounting.

Technical Context

The TIP42CN operates as a medium-power PNP bipolar junction transistor with base-controlled current amplification. Its design supports both linear mode (e.g., Class AB audio output) and saturated switching (e.g., relay drivers), with guaranteed h_FE linearity across I_C = 0.3 A to 3 A at V_CE = 4 V.

It features negative-polarity absolute maximum ratings: V_CBO = –100 V, V_CEO = –100 V, V_EBO = –5 V, and I_C = –6 A. Thermal performance is defined by T_J(max) = 150 °C and P_tot = 65 W at case temperature ≤ 25 °C.

Key Specifications

Pinout & Package

TO-220 package with vertical mounting orientation, metal tab electrically connected to collector (Pin 2), requiring insulated mounting hardware when used with grounded heatsinks.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJD42C and BD912, the TIP42CN provides optimal balance of through-hole serviceability, pre-binned h_FE, and proven thermal performance in legacy audio and linear power designs - especially where TO-220 mechanical fit and known SOA curves are critical.

Availability

TIP42CN is available at Aetrix Electronics and suitable for audio amplifier output stages, linear DC power supplies, motor control drivers, and relay interface circuits requiring stable component supply and long-term manufacturability.

Supply support for TIP42CN 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 TIP41CN/TIP42CN series belongs to ST's legacy silicon power transistor product line, engineered specifically for cost-sensitive, medium-power linear and switching applications in consumer audio and industrial power systems.

FAQ

Is the TIP42CN pin-compatible with the TIP42C?

Yes - the TIP42CN is a direct enhancement of the TIP42C with identical TO-220 pinout (Emitter-Collector-Base), improved h_FE linearity, and tighter parameter grouping. No PCB layout change is required for drop-in replacement in existing designs.

What is the significance of h_FE Group R, O, and Y?

These are factory-selected DC current gain bins: Group R (h_FE = 30–42), Group O (15–28), and Group Y (24–44). Each batch ships one group only, enabling consistent bias network design without gain variation testing during production.

Can the TIP42CN be used in parallel configurations?

Yes, but requires emitter ballast resistors (typically 0.1–0.47 Ω) to ensure current sharing. The device's positive thermal coefficient of V_BE supports inherent thermal stability, unlike MOSFETs which require external gate resistors for oscillation suppression.

Does the metal tab connect to a specific pin internally?

Yes - the metal tab is internally connected to Pin 2 (Collector). When mounted to a heatsink, electrical isolation (e.g., mica washer + shoulder washer) is mandatory unless the heatsink is floating or referenced to the collector potential.