onsemi 2N6043G

Overview

2N6043G from onsemi is an NPN Darlington power transistor in TO-220 package, rated for 60 V_CEO(sus), 8 A continuous collector current, and 75 W power dissipation at T_C = 25°C. It delivers high DC current gain (h_FE = 1000 min @ I_C = 4.0 A), low V_CE(sat) ≤ 2.0 V, and built-in base-emitter shunt resistors-designed for medium-power linear amplification and low-speed switching in industrial control and power supply circuits.

For engineers reviewing the 2N6043G datasheet, pinout, applications, or equivalent options, key selection criteria include its 60 V sustaining voltage, Darlington architecture enabling high-current drive with low base current, thermal resistance of 1.67°C/W (junction-to-case), and Pb-free TO-220 packaging compliant with RoHS and UL 94 V-0.

Technical Context

The 2N6043G implements a monolithic Darlington pair with integrated base-emitter shunt resistors to ensure reliable turn-off and reduce external component count. Its design targets stable operation up to +150°C junction temperature and supports both linear amplifier and saturated-switching modes.

Electrical behavior is characterized by h_FE ≥ 1000 at I_C = 4.0 A, V_CE(sat) ≤ 2.0 V under I_C = 4.0 A / I_B = 16 mA conditions, and C_ob = 200 pF at V_CB = 10 V - confirming suitability for low-frequency (<1 MHz) power control where gain stability and saturation performance outweigh high-speed requirements.

Key Specifications

Pinout & Package

2N6043G uses the standard TO-220 (Case 221A) package with three leads: Collector (tab), Base, and Emitter - mounted with the tab electrically connected to the collector and thermally coupled to the heatsink.

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 2N6043G offers superior thermal performance (R_θJC = 1.67°C/W) and higher continuous current capability (8 A vs. 5 A), making it preferred for thermally constrained linear regulator or high-duty-cycle switching applications where junction temperature control is critical.

Availability

2N6043G is available at Aetrix Electronics and suitable for industrial motor control, DC power supply regulation, heating element driver, and AC solid-state relay interface applications requiring stable component supply and long-term manufacturability.

Supply support for 2N6043G 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 2N6043G belongs to onsemi's legacy plastic medium-power complementary silicon transistor family, engineered for general-purpose amplifier and low-speed switching applications where reliability, thermal robustness, and high DC gain are prioritized over RF or high-frequency performance.

FAQ

What is the maximum junction temperature specification for the 2N6043G?

The 2N6043G has an operating junction temperature range of –65°C to +150°C. This allows deployment in harsh industrial environments such as motor drives and power supplies where ambient temperatures exceed 85°C, provided thermal design maintains T_J ≤ 150°C using the specified R_θJC = 1.67°C/W and appropriate heatsinking. The 2N6043G datasheet confirms this rating under JEDEC Registered Data conditions.

Does the 2N6043G require an external base resistor for turn-on?

The 2N6043G does not require an external base resistor for basic turn-on functionality, but a series base resistor is recommended to limit peak base current and ensure controlled switching. While the device includes a built-in base-emitter shunt resistor for turn-off, the absence of internal base current limiting means external resistance is necessary to prevent excessive I_B during drive - especially when interfacing with logic-level sources. The 2N6043G's typical V_BE(on) is 2.8 V, guiding proper resistor selection.

Can the 2N6043G be used in parallel configurations for higher current handling?

The 2N6043G is not recommended for direct paralleling without individual emitter resistors due to gain and V_BE mismatches between units, which cause current imbalance and potential thermal runaway. If higher current is needed, use a single higher-rated device or implement forced current sharing with precision emitter degeneration resistors per 2N6043G unit. Thermal coupling and matching layout are essential - the 2N6043G's Darlington structure increases sensitivity to parameter variation versus single-stage transistors.

Is the 2N6043G pin-compatible with the TIP122?

Yes, the 2N6043G is pin-compatible with the TIP122 in TO-220 packages: Collector (tab), Base, and Emitter occupy identical physical positions. However, the 2N6043G offers higher continuous current (8 A vs. 5 A) and lower thermal resistance (1.67°C/W vs. 2.0°C/W), meaning it can deliver more power in the same footprint - though PCB layout must verify mechanical clearance for the tab and thermal pad mounting. Both share identical pinout and mounting hole pattern.

What is the safe operating area (SOA) limitation for the 2N6043G at DC operation?

At DC operation, the 2N6043G's safe operating area is thermally limited to 75 W at T_C = 25°C, decreasing linearly above that temperature at 0.60 W/°C. Figure 5 of the 2N6043G datasheet shows the SOA boundary is defined by second breakdown at short pulses and by junction temperature at DC - with maximum I_C dropping to ~4 A at V_CE = 30 V under continuous conditions. Exceeding these boundaries risks permanent degradation of the 2N6043G's Darlington structure.