onsemi 2N6427_D26Z

Overview

2N6427_D26Z from Fairchild Semiconductor is an NPN Darlington transistor optimized for high-current-switching applications requiring DC current gain ≥10,000 at IC = 10 mA and VCE = 5.0 V, with continuous collector current up to 1.2 A and VCEO = 40 V, housed in TO-92 package with D26Z tape-and-reel packaging (2,000 units/reel). It serves as a high-gain interface switch in relay drivers and lamp controllers.

For engineers reviewing the 2N6427_D26Z datasheet, pinout, applications, or equivalent options, key selection criteria include verified hFE ≥14,000 at IC = 500 mA, VCE(sat) ≤1.5 V under same conditions, thermal resistance RθJA = 200 °C/W on FR-4 PCB, and TO-92 mechanical compatibility with standard lead-forming tooling.

Technical Context

This device implements a monolithic NPN Darlington pair structure fabricated in Fairchild's Process 05, delivering ultra-high DC current gain while maintaining low saturation voltage. Its breakdown ratings-VCEO = VCB0 = 40 V and VEBO = 12 V-define safe operating limits for inductive load switching.

Thermal performance is characterized by RθJA = 200 °C/W on a 1.6" × 1.6" × 0.06" FR-4 board, enabling 625 mW total dissipation at TA = 25°C with linear derating of 5.0 mW/°C above that temperature. Cutoff leakage (ICEO ≤ 1.0 µA at VCE = 25 V) ensures reliable off-state isolation in low-power control circuits.

Key Specifications

Pinout & Package

2N6427_D26Z is supplied in the industry-standard TO-92 package (Fairchild PKG Code 92), with straight leads, no lead clip, and EOL code D26Z indicating tape-and-reel configuration per Figure 2.0 (Style "A" reeling). Pin orientation follows standard C-B-E layout when flat side faces viewer and leads point downward.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPSA14, 2N6427_D26Z offers +10 V higher VCEO headroom for 36 V industrial rails; compared with 2N6426, it provides NPN polarity required for low-side switching, making it non-interchangeable despite identical package and current rating.

Availability

2N6427_D26Z is available at Aetrix Electronics and suitable for relay drivers, lamp dimmers, solenoid actuators, and industrial sensor interfaces requiring stable component supply across long-lifecycle embedded programs.

Supply support for 2N6427_D26Z 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

Fairchild Semiconductor was a U.S.-based semiconductor manufacturer specializing in power management, analog, and discrete devices before its acquisition by ON Semiconductor in 2016.

The 2N6427_D26Z belongs to Fairchild's legacy NPN Darlington transistor family designed specifically for high-gain, medium-current switching in industrial control, appliance, and automation equipment.

FAQ

What is the maximum continuous collector current rating for the 2N6427_D26Z?

The 2N6427_D26Z has a maximum continuous collector current (IC) rating of 1.2 A at TA = 25°C. This rating assumes proper PCB thermal management-specifically, mounting on a 1.6" × 1.6" × 0.06" FR-4 board-and derates linearly by 5.0 mW/°C above 25°C ambient. At 70°C ambient, usable IC drops to approximately 0.975 A based on thermal limits.

Does the 2N6427_D26Z have the same pinout as the MPSA14?

Yes, the 2N6427_D26Z uses the standard TO-92 package with C-B-E pinout (collector, base, emitter), matching the physical pin configuration of the MPSA14. Both devices share identical lead spacing and mechanical footprint, enabling mechanical interchangeability in through-hole layouts-though electrical differences (e.g., VCEO = 40 V vs. 30 V) must be validated per application.

What is the typical DC current gain (hFE) of the 2N6427_D26Z at 500 mA collector current?

The 2N6427_D26Z delivers a minimum hFE of 14,000 at IC = 500 mA, VCE = 5.0 V, and TA = 25°C. This value is confirmed in the Electrical Characteristics table and reflects the Darlington structure's ability to sustain high gain even at elevated currents-critical for ensuring full saturation with minimal base drive in microcontroller-driven switches.

Is the 2N6427_D26Z suitable for switching inductive loads like relays or solenoids?

Yes, the 2N6427_D26Z is explicitly designed for inductive load switching. Its VCEO = 40 V and robust SOA support safe turn-off of 24 V relays and solenoids. For reliability, always use a flyback diode (e.g., 1N4007) across the load to clamp inductive kickback, as specified in Fairchild's application guidance for Darlington transistors.

What does the suffix "D26Z" indicate in the part number 2N6427_D26Z?

The "D26Z" suffix identifies the packaging configuration: TO-92 device supplied in tape-and-reel format (Style "A") with 2,000 units per reel, per Fairchild's TO-92 Tape and Reel Data documentation. It specifies reeling direction (first wire off is emitter), adhesive tape position (top side), and flat side orientation (bottom), ensuring compatibility with automated pick-and-place equipment.