onsemi PN2222TAR

Overview

PN2222TAR from ON Semiconductor is an NPN general-purpose bipolar junction transistor (BJT) designed for medium-power amplification and switching applications, with a 40 V collector-emitter breakdown voltage (V_CEO), 1.0 A maximum collector current (I_C), and DC current gain (h_FE) ranging from 35 to 300 depending on operating conditions. It is commonly used in low-frequency signal amplification, relay drivers, and digital logic interface circuits.

For engineers reviewing the PN2222TAR datasheet, pinout, applications, or equivalent options, key selection considerations include its TO-92 package thermal resistance (R_θJA = 200 °C/W), saturation voltage (V_CE(sat) = 0.3 V at I_C = 150 mA), and 300 MHz current-gain bandwidth product (f_T).

Technical Context

The PN2222TAR operates as a standard NPN BJT with fixed emitter-base and collector-base junctions, requiring external biasing networks for linear amplification or saturated switching. Its performance is characterized by specified h_FE ranges across collector currents (100 μA to 500 mA) and temperature (–55 °C to +150 °C), and defined switching times (t_d = 10 ns, t_r = 25 ns, t_s = 225 ns, t_f = 60 ns) under standardized test conditions.

Thermal design must account for its 625 mW total device dissipation at 25 °C, derating at 5.0 mW/°C above ambient, and junction-to-ambient thermal resistance of 200 °C/W on a standard FR-4 PCB. Electrical behavior includes low noise figure (4.0 dB at 1 kHz), input capacitance (C_ibo = 25 pF), and output capacitance (C_obo = 8.0 pF).

Key Specifications

Pinout & Package

PN2222TAR is housed in a TO-92 plastic package with straight leads (JEDEC TO-92 compliant), featuring three terminals arranged in E-B-C order when viewed with flat side facing outward and leads pointing down.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMBT2222ALT1G, PN2222TAR offers easier manual prototyping and higher thermal margin on through-hole boards; compared with PN2222A, PN2222TAR is the same device under ON Semiconductor's current part numbering system, ensuring long-term supply continuity and documentation alignment.

Availability

PN2222TAR is available at Aetrix Electronics and suitable for industrial control systems, consumer audio signal conditioning, and embedded microcontroller peripheral interfacing requiring stable component supply and long-lifecycle support.

Supply support for PN2222TAR 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 is a global semiconductor manufacturer specializing in energy-efficient power management, analog, and sensing solutions for automotive, industrial, and consumer markets.

PN2222TAR belongs to ON Semiconductor's general-purpose bipolar transistor product line, engineered for cost-sensitive, high-reliability discrete amplification and switching in non-critical industrial and commercial applications.

FAQ

What is the maximum continuous collector current rating for PN2222TAR?

The PN2222TAR has an absolute maximum collector current (I_C) rating of 1.0 A, but its recommended continuous operating current is 500 mA per the datasheet's switching and amplification use cases. Exceeding 500 mA requires careful thermal management due to its 625 mW power dissipation limit and 200 °C/W junction-to-ambient thermal resistance. Always verify thermal performance in your specific PCB layout when using PN2222TAR near its limits.

Is PN2222TAR pin-compatible with the legacy PN2222A?

Yes, PN2222TAR is pin-compatible with PN2222A - both use the same TO-92 package with identical E-B-C lead configuration and identical electrical specifications. The change from PN2222A to PN2222TAR reflects ON Semiconductor's post-Fairchild integration naming convention, replacing underscores with dashes and aligning with their internal ordering systems. PN2222TAR is the current-orderable version of the same silicon die.

What is the typical noise figure of PN2222TAR and at what conditions is it measured?

The PN2222TAR has a typical noise figure of 4.0 dB, measured at I_C = 100 μA, V_CE = 10 V, source resistance R_S = 1.0 kΩ, and frequency f = 1.0 kHz. This value is specified in the "Small Signal Characteristics" section of the datasheet and confirms its suitability for low-noise preamplifier stages in audio and sensor signal chains where signal integrity is critical.

Does PN2222TAR support high-frequency switching applications?

PN2222TAR supports switching up to approximately 10 MHz in optimized layouts, based on its 300 MHz current-gain bandwidth product (f_T) and documented switching times (t_d = 10 ns, t_r = 25 ns, t_s = 225 ns, t_f = 60 ns). However, its 225 ns storage time limits practical PWM use to ~10 kHz for reliable turn-off; for >100 kHz switching, consider RF-optimized transistors or MOSFETs instead of PN2222TAR.

What is the thermal resistance (R_θJA) of PN2222TAR and how does it affect PCB layout?

PN2222TAR has a junction-to-ambient thermal resistance (R_θJA) of 200 °C/W on a standard FR-4 PCB (76 mm × 114 mm × 1.57 mm) with minimum land pattern. This means each watt of dissipated power raises the junction temperature by 200 °C above ambient - so at 500 mA and V_CE(sat) ≈ 0.6 V, ~300 mW dissipation yields ~60 °C rise. To maintain reliability, keep ambient below 90 °C or increase copper area around the TO-92 pad to reduce R_θJA in your PN2222TAR layout.