onsemi TN6726A

Overview

TN6726A from Fairchild Semiconductor is a PNP general-purpose amplifier transistor rated for 30 V V_CEO, 1.5 A continuous collector current, and 1.0 W power dissipation at 25°C-designed for medium-power switching and linear amplification in industrial control and power management circuits.

For engineers reviewing the TN6726A datasheet, pinout, applications, or equivalent options, key selection criteria include its PNP polarity, TO-226 and SOT-223 dual-package availability, -55°C to +150°C junction temperature range, 55–250 h_FE DC gain across 10 mA–1.0 A, and 0.5 V V_CE(sat) at I_C = 1.0 A / I_B = 100 mA.

Technical Context

The TN6726A operates as a medium-power PNP bipolar junction transistor with negative-polarity voltage and current ratings, requiring reverse-biased base-emitter and collector-emitter junctions for conduction. Its design supports both linear amplification (with h_FE ≥ 55 at I_C = 10 mA) and saturated switching (V_CE(sat) ≤ 0.5 V at β = 10).

Thermal performance is defined by R_θJC = 50°C/W and R_θJA = 125°C/W on FR-4 PCB (36 mm × 18 mm × 1.5 mm, 6 cm² collector pad), enabling stable operation up to 150°C junction temperature. Safe operating area (SOA) curves confirm pulsed capability up to 100 µs at V_CE = 10 V and I_C = 1.0 A.

Key Specifications

Pinout & Package

Package: TO-226 (also known as TO-92 variant) and SOT-223 - both standardized through-hole and surface-mount options with identical pinout: Emitter (Pin 1), Base (Pin 2), Collector (Pin 3). The TO-226 package uses radial leads; SOT-223 features a thermally enhanced 4-pin configuration with Pin 4 as exposed collector tab.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP general-purpose amplifier applications.

Compared with MJD2955 and BC807-40, the TN6726A uniquely balances 1.5 A current handling, 30 V breakdown, and dual TO-226/SOT-223 packaging-making it optimal for medium-power industrial switching where thermal headroom and layout flexibility are critical.

Availability

TN6726A is available at Aetrix Electronics and suitable for industrial relay drivers, linear voltage regulator pass elements, DC-DC converter error amplifiers, and motor control current sinks requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for TN6726A 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 (now part of ON Semiconductor) is a legacy analog and discrete semiconductor manufacturer specializing in power management, signal conditioning, and interface solutions for industrial and automotive markets.

The TN6726A belongs to Fairchild's general-purpose PNP transistor product line, engineered for robust medium-power amplification and switching in harsh-environment applications where reliability and thermal resilience are prioritized over ultra-high speed or RF performance.

FAQ

What is the maximum continuous collector current rating for the TN6726A?

The TN6726A has a maximum continuous collector current (I_C) rating of 1.5 A at T_A = 25°C. This rating decreases with rising ambient temperature due to its 8 mW/°C thermal derating factor. At 100°C ambient, the usable I_C drops to approximately 900 mA. The TN6726A maintains safe operation within its SOA curve even under pulsed conditions up to 100 µs.

Does the TN6726A support both TO-226 and SOT-223 packages?

Yes, the TN6726A is manufactured in both TO-226 (radial lead, through-hole) and SOT-223 (surface-mount) packages, sharing identical electrical specifications and pinout: Emitter (Pin 1), Base (Pin 2), Collector (Pin 3). The SOT-223 variant includes an exposed collector tab (Pin 4) for improved thermal dissipation, while the TO-226 version relies on lead-frame conduction.

What is the typical DC current gain (h_FE) of the TN6726A at different operating points?

The TN6726A exhibits h_FE = 55–250 depending on collector current: minimum 55 at I_C = 10 mA, 60 at I_C = 100 mA, and 50 at I_C = 1.0 A (all at V_CE = 1.0 V). This wide gain range reflects its suitability for both small-signal amplification and high-current switching-designers should verify bias stability across the intended I_C range using the published pulsed h_FE curves.

How does the TN6726A's saturation voltage compare to similar PNP transistors?

The TN6726A achieves V_CE(sat) ≤ 0.5 V at I_C = 1.0 A and I_B = 100 mA (β = 10), which is competitive among medium-power PNP devices. For comparison, the MJD2955 specifies V_CE(sat) = 1.8 V at I_C = 4 A, while the BC807-40 reaches 0.7 V at I_C = 100 mA. This low saturation voltage directly reduces conduction loss in TN6726A-based switch designs.

Is the TN6726A suitable for automotive under-hood applications?

Yes-the TN6726A is rated for junction temperatures from -55°C to +150°C and features robust SOA characteristics validated for pulsed operation. Its 30 V V_CEO and 1.5 A I_C meet requirements for non-safety-critical under-hood functions such as HVAC blower control, fuel pump drivers, and body control module load switching-provided proper PCB thermal design per the 6 cm² collector pad recommendation.