Microchip Technology 2N3773

Overview

2N3773 from STMicroelectronics is a high-power planar NPN bipolar junction transistor in a TO-3 metal package, rated for 140 V V_CEO, 16 A continuous collector current, and 150 W total power dissipation at T_c ≤ 25 °C; it is designed for linear audio amplifiers and inductive switching circuits such as motor drivers and relay controls.

For engineers reviewing the 2N3773 datasheet, 2N3773 pinout, 2N3773 application, or 2N3773 equivalent, key selection considerations include its 1.17 °C/W thermal resistance (junction-to-case), low 1.4 V V_CE(sat) at 8 A/0.8 A drive, sustained 160 V V_CEV under reverse-biased base conditions, and second-breakdown-limited 5 A I_S/B at 30 V.

Technical Context

The 2N3773 operates as a single NPN silicon power transistor with planar epitaxial construction and gold-doped base region for improved switching speed and ruggedness. Its safe operating area (SOA) is defined by both thermal limits and second-breakdown constraints, with specified I_S/B = 5 A at V_CE = 30 V for t = 1 s non-repetitive pulses.

It features low saturation voltage (1.4 V at IC = 8 A, IB = 0.8 A), high DC current gain (h_FE = 15–60 across 8–16 A), and robust voltage ratings including V_CBO = 160 V and V_EBO = 7 V - enabling use in high-voltage linear and switching topologies without external snubbing in many cases.

Key Specifications

Pinout & Package

2N3773 is housed in a hermetically sealed TO-3 metal package with electrically isolated collector tab. The case serves as the collector terminal; emitter and base are brought out via insulated leads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJE13009 and 2N6284, the 2N3773 offers the best balance of low saturation voltage, proven linear stability, and manufacturable thermal performance in legacy TO-3-based amplifier and industrial control designs - making it preferred where fidelity and SOA predictability outweigh raw voltage or current extremes.

Availability

2N3773 is available at Aetrix Electronics and suitable for audio power amplifiers, DC motor drivers, relay/solenoid controllers, and linear regulator pass elements requiring stable component supply and long-term industrial availability.

Supply support for 2N3773 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power transistors, sensors, and analog ICs for industrial, automotive, and consumer markets.

The 2N3773 belongs to ST's legacy high-power bipolar transistor family, developed specifically for ruggedized linear amplification and inductive switching in industrial automation and professional audio systems.

FAQ

Is the 2N3773 RoHS-compliant and lead-free?

Yes, the 2N3773 is offered in ECOPACK® packaging with lead-free second-level interconnect, compliant with JEDEC Standard JESD97 and EU RoHS Directive 2011/65/EU. The inner box label indicates the lead-free category and soldering profile limits.

What is the recommended base drive for reliable switching?

For reliable saturation, apply IB ≥ IC / h_FE(min) = 8 A / 15 ≈ 0.53 A minimum; ST recommends IB = 0.8 A for 8 A IC and IB = 3.2 A for 16 A IC. Use active base turn-off (−1.5 V V_BE) to minimize storage time in inductive switching.

Can the 2N3773 be used in parallel configurations?

Yes, but only with emitter ballast resistors (typically 0.1–0.22 Ω) to ensure current sharing. Due to h_FE variation and thermal coupling, unballasted paralleling risks thermal runaway; ST specifies derated SOA curves for multi-device layouts.

Is the 2N3773 still in active production?

No - STMicroelectronics has marked the 2N3773 as Obsolete Product(s). However, Aetrix Electronics maintains verified legacy stock with full traceability and provides extended lifecycle support, including obsolescence mitigation planning and cross-reference guidance.