Microchip Technology 2N2222AUB

Overview

2N2222AUB from Microsemi is a JANS-qualified NPN silicon switching transistor in a hermetically sealed ceramic surface-mount package (UBC variant), rated for V_CEO = 50 V, I_C = 800 mA, P_T = 0.5 W, and operating junction temperature up to +200°C - used in radiation-tolerant aerospace power switching and analog amplification stages.

For engineers reviewing the 2N2222AUB datasheet, 2N2222AUB pinout, 2N2222AUB application, or 2N2222AUB equivalent, this page delivers verified military-grade transistor specifications, TO-18-derived UBC package terminal mapping, switching timing data (t_on = 35 ns, t_off = 300 ns), h_FE range at multiple bias points, and qualified alternatives for high-reliability design-in.

Technical Context

The 2N2222AUB operates as a general-purpose bipolar junction transistor optimized for low-to-medium power switching and linear amplification in extreme environments. Its JANS qualification per MIL-PRF-19500/255 mandates screening for radiation hardness, thermal cycling, and hermeticity - with collector internally bonded to case for enhanced thermal path and EMI shielding.

It exhibits h_FE = 40–100 at I_C = 10 mA/V_CE = 10 V and h_fe ≥ 30 at 1 kHz, supporting stable DC gain and small-signal RF operation up to 100 MHz (|h_fe| ≥ 2.5). C_obo = 8.0 pF and C_ibo = 25 pF confirm suitability for fast-switching and broadband amplifier designs requiring controlled capacitance.

Key Specifications

Pinout & Package

2N2222AUB uses a 4-terminal ceramic surface-mount package (UBC variant) with metalized lid braze ring. Pin 1 = Base, Pin 2 = Emitter, Pin 3 = Collector (internally connected to case), Pin 4 = Lid braze ring (shielding/ground reference).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 2N2222AUA and 2N2222AL, the 2N2222AUB uniquely delivers JANS-level radiation tolerance, ceramic hermeticity, and lid-grounding capability - making it the sole option for mission-critical space, defense, and downhole systems demanding guaranteed performance at +200°C and beyond.

Availability

2N2222AUB is available at Aetrix Electronics and suitable for avionics power sequencing, satellite payload switching, downhole telemetry amplifiers, and radiation-hardened oscillators requiring stable component supply across extended temperature and radiation environments.

Supply support for 2N2222AUB 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

Microsemi (now part of Microchip Technology) is a U.S.-based semiconductor manufacturer specializing in high-reliability, radiation-hardened, and aerospace-grade components.

The 2N2222AUB belongs to Microsemi's legacy MIL-PRF-19500/255-qualified bipolar transistor family, designed specifically for mission-critical analog and switching functions in space, defense, and energy exploration systems.

FAQ

What is the package type and lead configuration of the 2N2222AUB?

The 2N2222AUB uses a 4-terminal surface-mount ceramic package (UBC variant) with Pin 1 = Base, Pin 2 = Emitter, Pin 3 = Collector (internally connected to case), and Pin 4 = lid braze ring. It is not a through-hole TO-18 device - the UBC version replaces the metal can with a ceramic lid sealed via braze ring for hermeticity and radiation tolerance.

Is the 2N2222AUB suitable for high-temperature operation beyond 150°C?

Yes - the 2N2222AUB is rated for junction temperatures from −65°C to +200°C and is fully characterized across that range. Its ceramic UBC package and JANS qualification ensure reliable operation in downhole, turbine, and space thermal environments where standard plastic or metal-can transistors fail.

Does the 2N2222AUB have radiation hardness certification?

Yes - the 2N2222AUB is JANS-qualified per MIL-PRF-19500/255, which includes mandatory radiation hardness assurance (RHA) testing for total ionizing dose (TID), enhanced low-dose-rate sensitivity (ELDRS), and single-event effects (SEE) screening - making it certified for use in geosynchronous and deep-space missions.

What is the thermal resistance (R_θJA) of the 2N2222AUB and how does it affect layout?

The 2N2222AUB has R_θJA = 325°C/W. Because Pin 3 (Collector) is internally bonded to the case, optimal thermal performance requires soldering the metal case and Pin 4 (lid braze ring) directly to a large, thermally conductive PCB ground plane - not relying solely on trace conduction.

How does the 2N2222AUB differ from the commercial 2N2222A in terms of electrical specs?

Electrically, the 2N2222AUB shares identical absolute maximum ratings and electrical characteristics (V_CEO, I_C, h_FE, t_on/t_off, C_obo) with other 2N2222A variants - the differentiation lies in packaging, screening, and reliability: only the UBC version offers JANS qualification, ceramic hermeticity, and lid grounding for radiation and vacuum applications.