onsemi 2N6038

Overview

2N6038 from onsemi is an NPN Darlington silicon power transistor in TO-225 package, rated for 60 V_CEO, 4.0 A continuous collector current, and 40 W total device dissipation at T_C = 25°C. It delivers high DC current gain (h_FE ≥ 750 at I_C = 2.0 A), low saturation voltage (V_CE(sat) ≤ 3.0 V at I_C = 4.0 A / I_B = 40 mA), and is designed for low-speed switching and linear amplifier applications in industrial control and power supply circuits.

For engineers reviewing the 2N6038 datasheet, pinout, applications, or equivalent options, key selection considerations include its 60 V V_CEO rating, Darlington configuration enabling high current drive with low base current, thermal resistance of 3.12°C/W (junction-to-case), and Pb-free TO-225 packaging compliant with RoHS.

Technical Context

The 2N6038 operates as a monolithic NPN Darlington pair, integrating two cascaded bipolar junction transistors to achieve high current gain while maintaining single-package convenience. Its safe operating area (SOA) is defined by second breakdown limits (5 ms pulse), thermal constraints (T_J ≤ 150°C), and bonding wire current capacity - validated per Figure 5 in the datasheet.

Electrical behavior is characterized at T_C = 25°C with specified test conditions: V_CE(sat) measured at I_C/I_B = 250, h_FE tested across three collector current levels (0.5 A, 2.0 A, 4.0 A), and Cob = 100 pF at V_CB = 10 V, f = 0.1 MHz - confirming suitability for audio-frequency amplification and relay-driving switch applications.

Key Specifications

Pinout & Package

2N6038 uses the TO-225 package (Case 77-09, Style 1), with mechanical dimensions D = 10.6–11.1 mm, E = 7.4–7.8 mm, L = 14.5–16.63 mm, and a backside collector tab (pins 2 and 4 electrically connected to collector). The package is Pb-free and RoHS compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJD127G and TIP122, the 2N6038 offers optimal balance of 60 V rating, 4 A current, and 3.12°C/W thermal resistance in a proven through-hole package - making it preferred for legacy industrial controls and repair replacements where mechanical and thermal interface consistency is critical.

Availability

2N6038 is available at Aetrix Electronics and suitable for motor control interfaces, DC power supply regulation, relay/solenoid drivers, and audio output stages requiring stable component supply, long-term obsolescence management, and traceable sourcing.

Supply support for 2N6038 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, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The 2N6038 belongs to onsemi's legacy plastic Darlington complementary silicon power transistor family, engineered for general-purpose amplifier and low-speed switching applications where high current gain, rugged packaging, and thermal reliability are prioritized over RF performance.

FAQ

What is the maximum collector-emitter voltage rating for the 2N6038?

The 2N6038 has a maximum collector-emitter voltage (V_CEO) rating of 60 Vdc, verified under open-base conditions with I_C = 100 mAdc. This rating defines the absolute upper limit for DC voltage applied between collector and emitter before risk of avalanche breakdown; operation above this value is not guaranteed and may cause permanent damage to the 2N6038.

Does the 2N6038 have a metal heatsink tab, and how is it electrically connected?

Yes, the 2N6038 in TO-225 package features a metal backside tab that is electrically connected to the collector (pins 2 and 4). This tab serves both thermal and electrical functions: it provides a low-resistance thermal path to an external heatsink (R_θJC = 3.12°C/W), and must be isolated from other circuit potentials unless intentionally used as the collector node - critical for safe mounting of the 2N6038 in power circuits.

What is the minimum DC current gain (h_FE) of the 2N6038 at 2.0 A collector current?

The 2N6038 guarantees a minimum DC current gain (h_FE) of 750 when tested at I_C = 2.0 Adc and V_CE = 3.0 Vdc at T_C = 25°C. This high gain enables efficient base current utilization - for example, driving 2 A load requires only ~2.7 mA base current - a key advantage of the Darlington configuration inherent to the 2N6038 design.

Can the 2N6038 be used in audio amplifier output stages?

Yes, the 2N6038 is suitable for Class AB audio output stages, particularly when paired with its complementary PNP counterpart 2N6039. Its small-signal current gain |h_fe| ≥ 25 at 1 MHz and output capacitance C_ob = 100 pF support full-audio bandwidth operation. Verified performance in Figure 7 shows stable h_FE across –55°C to 125°C, confirming reliability in wide-temperature audio enclosures using the 2N6038.

Is the 2N6038 RoHS compliant and lead-free?

Yes, the 2N6038G variant is explicitly designated as Pb-free and RoHS compliant per the onsemi datasheet revision 15 (December 2013). The "G" suffix confirms lead-free plating and UL 94 V-0 rated epoxy encapsulation. No lead content is present in solderable terminations or mold compound, satisfying EU RoHS Directive 2011/65/EU and related global environmental requirements for the 2N6038.