onsemi BC327BU

Overview

BC327BU from ON Semiconductor is a PNP epitaxial silicon transistor designed for low-power switching and linear amplification, with V_CEO = −45 V, I_C = −800 mA, h_FE up to 630 at −100 mA, and f_T = 100 MHz. It serves as a complement to BC337/BC338 in push-pull amplifier stages and discrete logic-level inverters.

For engineers reviewing the BC327BU datasheet, pinout, applications, or equivalent options, key selection criteria include its TO-92 package compatibility, −50 V V_CES rating, −1.2 V V_BE(on) at −300 mA, thermal resistance of 200 °C/W, and h_FE classification options (16/25/40).

Technical Context

The BC327BU operates as a general-purpose PNP bipolar junction transistor with fixed-emitter biasing capability and DC current gain controlled by collector current level and V_CE. Its saturation voltage of −0.7 V at −500 mA/−50 mA enables efficient low-side switching in discrete power control circuits.

Thermal performance is defined by R_θJA = 200 °C/W on standard FR-4 PCBs, and its f_T = 100 MHz supports audio-frequency amplification and fast digital switching up to ~10 MHz with appropriate drive and load conditions.

Key Specifications

Pinout & Package

BC327BU is housed in a TO-92 3L plastic package with standardized lead configuration: lead 1 = Collector, lead 2 = Base, lead 3 = Emitter - verified per Fairchild/ON Semiconductor mechanical drawings and pinout diagrams.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP bipolar transistor applications.

Compared with BC327-25TA, BC327BU offers identical electrical performance but bulk packaging for lab use and flexible binning; versus MPSA92, it trades off voltage rating for higher current capacity and native pinout compatibility in standard BJT layouts.

Availability

BC327BU is available at Aetrix Electronics and suitable for audio driver circuits, discrete logic inverters, relay interface modules, and current mirror references requiring stable component supply and long-term obsolescence management.

Supply support for BC327BU 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 power management, analog, sensors, and discrete devices, with headquarters in Phoenix, Arizona.

The BC327BU belongs to ON Semiconductor's general-purpose bipolar transistor product line, engineered for cost-sensitive, high-reliability discrete signal conditioning and power control in industrial and consumer electronics.

FAQ

What is the pin configuration of BC327BU?

The BC327BU uses a standard TO-92 3L package with pin 1 = Collector, pin 2 = Base, and pin 3 = Emitter - confirmed in Fairchild/ON Semiconductor mechanical documentation and consistent across all BC327 variants. This configuration differs from NPN counterparts like BC337, which share the same physical outline but reversed polarity and complementary pin roles. Always verify orientation via the flat side and lead numbering before PCB layout.

Does BC327BU have a specified h_FE grade?

No, BC327BU is a bulk-packaged variant without guaranteed h_FE binning; its gain falls within the full BC327 family range (100–630). For design-critical applications requiring known gain, select graded versions such as BC327-16BU (100–250), BC327-25BU (160–400), or BC327-40BU (250–630). The BC327BU datasheet lists min/max h_FE values but does not assign a specific classification label.

Can BC327BU replace BC327-25 in existing designs?

Yes, BC327BU is electrically identical to BC327-25 in maximum ratings and typical performance, but lacks guaranteed h_FE binning. If the original design relies on the 160–400 h_FE range for stable biasing, BC327BU may exhibit wider gain variation and require verification of operating point margins. For prototyping or non-critical switching, BC327BU is functionally interchangeable; for production, use BC327-25BU or BC327-25TA to ensure consistency.

What is the maximum safe operating temperature for BC327BU?

The BC327BU has a maximum junction temperature (T_J) of 150 °C and storage temperature range of −55 to +150 °C. At ambient temperatures above 25 °C, power dissipation must be derated at 5 mW/°C due to its 200 °C/W thermal resistance. To maintain reliability, keep case temperature below 125 °C under continuous load; use heatsinking or airflow if dissipating >300 mW in enclosed environments.

Is BC327BU RoHS compliant and lead-free?

Yes, BC327BU is RoHS compliant and lead-free, consistent with ON Semiconductor's post-Fairchild integration environmental policies. The device meets EU Directive 2011/65/EU and is manufactured using Pb-free molding compounds and termination finishes. Full compliance documentation, including substance declarations and test reports, is available through ON Semiconductor's Quality Portal or authorized distributors upon request.