onsemi 2N6426RLRA

Overview

2N6426RLRA from ON Semiconductor is a silicon NPN Darlington transistor in TO-92 package, rated for 40 V_CEO, 500 mA continuous collector current, and 1.5 W total dissipation at T_C = 25°C. It delivers h_FE ≥ 20,000 at I_C = 10 mA and supports low-saturation switching in relay drivers and small-signal amplification stages.

For engineers reviewing the 2N6426RLRA datasheet, pinout, applications, or equivalent options, key selection criteria include verified DC current gain (20k–200k), V_CE(sat) ≤ 0.71 V at I_C/I_B = 100, thermal resistance R_JC = 83.3°C/W, and TO-92 mechanical compatibility with legacy through-hole layouts.

Technical Context

This Darlington pair integrates two cascaded NPN transistors on a single die to achieve high current gain while maintaining standard three-terminal operation. Its internal structure enables base drive reduction by ~100× compared to single transistors at matched collector currents.

Electrical behavior is characterized by low V_BE(sat) = 1.52 V (typ) at I_C = 500 mA, noise figure NF = 3.0 dB (typ) at 1 kHz, and f_T ≈ 2.4 MHz (2N6426 variant). Small-signal parameters-including h_ie = 100 kΩ (min) and C_ibo = 10 pF (typ)-are specified under defined bias and frequency conditions.

Key Specifications

Pinout & Package

2N6426RLRA uses the industry-standard TO-92 (Case 29, Style 1) plastic package with 3 leads. Lead spacing matches JEDEC TO-226AA footprint, enabling drop-in replacement in existing through-hole PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPSA13 and ULN2003A, the 2N6426RLRA offers superior voltage headroom (40 V vs. 30 V), highest guaranteed h_FE (20k min), and lowest V_CE(sat)-making it optimal for single-load, high-reliability, space-constrained designs where discrete simplicity is preferred.

Availability

2N6426RLRA is available at Aetrix Electronics and suitable for relay drivers, LED current regulators, DC motor controllers, and low-noise preamplifiers requiring stable component supply across industrial and embedded production cycles.

Supply support for 2N6426RLRA 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

ON Semiconductor (now part of onsemi) is a global semiconductor supplier specializing in energy-efficient power management, analog, and sensing technologies for automotive, industrial, and cloud infrastructure markets.

The 2N6426RLRA belongs to ON Semiconductor's legacy bipolar transistor product line, engineered for high-gain, low-saturation switching in cost-sensitive, reliability-critical linear and switching applications.

FAQ

What is the maximum continuous collector current rating for the 2N6426RLRA?

The 2N6426RLRA is rated for 500 mAdc continuous collector current at T_A = 25°C. Derating applies above ambient temperature: 5.0 mW/°C for free-air operation and 12 mW/°C when case-mounted to heatsink. At T_C = 25°C, its 1.5 W power limit supports higher current pulses within thermal limits.

Does the 2N6426RLRA have built-in protection diodes or resistors?

No, the 2N6426RLRA is a bare Darlington transistor without integrated clamp diodes or base resistors. External flyback diodes must be added across inductive loads, and base current limiting resistors are required to prevent overdrive. This differs from array ICs like ULN2003A which integrate both features.

Is the 2N6426RLRA RoHS-compliant and lead-free?

Yes, the 2N6426RLRA is manufactured in Pb-free (lead-free) packaging per ON Semiconductor's compliance program. The "G" suffix denotes RoHS-compliant variants, but 2N6426RLRA itself meets J-STD-020 MSL-1 requirements and contains no intentionally added lead.

How does the 2N6426RLRA compare to the 2N6427 in terms of DC current gain?

The 2N6426RLRA guarantees h_FE ≥ 20,000 at I_C = 10 mA, while the 2N6427 specifies h_FE ≥ 10,000 under identical conditions. At I_C = 500 mA, the 2N6426RLRA maintains h_FE ≥ 20,000 versus 14,000 for 2N6427-making the 2N6426RLRA preferable for high-current, low-drive applications.

Can the 2N6426RLRA be used in linear amplifier configurations?

Yes, the 2N6426RLRA supports linear operation with verified small-signal parameters: h_fe = 20,000 (typ), h_ie = 100 kΩ (min), and NF = 3.0 dB (typ) at 1 kHz. Its f_T ≈ 2.4 MHz and C_obo = 5.4 pF (typ) enable stable gain up to ~200 kHz in emitter-follower or common-emitter topologies.