onsemi 2N3906RLRA

Overview

2N3906RLRA from ON Semiconductor is a PNP bipolar junction transistor (BJT) designed for general-purpose amplification and switching at collector currents from 10 mA to 100 mA. It features −40 V collector-emitter breakdown voltage, −200 mA continuous collector current rating, and DC current gain (h_FE) ranging from 60 to 300 depending on operating conditions. It is commonly used in low-power signal inversion, level shifting, and discrete logic interface circuits.

For engineers reviewing the 2N3906RLRA datasheet, pinout, applications, or equivalent options, key selection criteria include its TO-92 package thermal resistance (R_θJA = 200 °C/W), −0.25 V V_CE(sat) at −10 mA/−1 mA drive, and 250 MHz f_T bandwidth - critical for analog gain staging and fast-switching digital control.

Technical Context

The 2N3906RLRA operates as a standard PNP BJT with base-controlled current amplification. Its h_FE varies significantly with collector current: 100 at −10 mA, 60 at −50 mA, and 30 at −100 mA, requiring bias design awareness. The device exhibits low noise figure (4.0 dB at 10 Hz–15.7 kHz) and predictable saturation behavior, supporting stable operation in Class-A amplifiers and saturated-switch configurations.

Thermal performance is defined by a 625 mW total power dissipation at 25 °C, derating linearly at 5.0 mW/°C above ambient. Its absolute maximum ratings include −40 V V_CEO, −5.0 V V_EBO, and −55 to +150 °C operating temperature range - aligning with industrial-grade discrete requirements.

Key Specifications

Pinout & Package

2N3906RLRA is housed in a through-hole TO-92 package (JEDEC TO-92 compliant), with straight leads and EBC pin configuration (Emitter–Base–Collector, viewed from flat side with leads down).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 2N3906RLRA, MMBT3906 offers footprint reduction at the cost of thermal performance, while BC327-40 delivers enhanced current and gain capability in identical through-hole packaging - enabling direct mechanical replacement with circuit recalibration.

Availability

2N3906RLRA is available at Aetrix Electronics and suitable for discrete amplifier stages, GPIO expansion interfaces, and power rail enable circuits requiring stable component supply across industrial, consumer, and embedded design cycles.

Supply support for 2N3906RLRA 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, sensors, and discrete devices for automotive, industrial, and cloud infrastructure markets.

The 2N3906RLRA belongs to ON Semiconductor's legacy general-purpose BJT product line, originally developed by Fairchild Semiconductor and optimized for cost-sensitive, high-reliability discrete signal conditioning and switching applications.

FAQ

What is the pin configuration of the 2N3906RLRA?

The 2N3906RLRA uses a TO-92 package with Emitter–Base–Collector (EBC) pinout when viewed from the flat side with leads pointing downward. Pin 1 is Emitter, Pin 2 is Base, and Pin 3 is Collector - confirmed by Fairchild/ON Semiconductor package drawings ZA03D and ZA03F. This configuration is consistent across all 2N3906 variants and must be verified during PCB layout to avoid functional reversal.

Does the 2N3906RLRA support switching at 1 MHz?

Yes, the 2N3906RLRA supports reliable switching at 1 MHz due to its 250 MHz f_T and sub-100 ns total switching times (t_d + t_r + t_s + t_f ≈ 370 ns). At I_C = −10 mA, storage time t_s is 225 ns - the dominant delay factor - so practical duty-cycle-limited operation up to ~1 MHz is achievable with appropriate base drive and load impedance.

What is the maximum safe operating temperature for 2N3906RLRA?

The 2N3906RLRA has a maximum junction temperature (T_J) of +150 °C and an operating ambient range of −55 °C to +150 °C. When mounted on a standard FR-4 PCB, its thermal resistance is R_θJA = 200 °C/W. To stay within safe limits, power dissipation must be limited to ≤312.5 mW at 85 °C ambient - calculated using T_J = T_A + (P × R_θJA).

Can 2N3906RLRA replace BC557 in existing designs?

The 2N3906RLRA can functionally replace BC557 in many low-current amplifier and switching roles, but differences exist: BC557 has higher h_FE (125–800 vs. 60–300), same −45 V V_CEO, and slightly better noise performance. No PCB changes are needed since both use TO-92 with identical EBC pinout, but base resistor values may require adjustment to accommodate gain variance.

Is 2N3906RLRA RoHS compliant and lead-free?

Yes, 2N3906RLRA is RoHS compliant and lead-free, meeting EU Directive 2011/65/EU and ON Semiconductor's environmental specifications. The "RLRA" suffix denotes tape-and-reel packaging with lead-free finish and halogen-free molding compound - verified in ON Semiconductor's official product change notices and packaging datasheets.