onsemi BCW60B

Overview

BCW60B from Fairchild Semiconductor is an NPN epitaxial silicon general-purpose transistor in SOT-23 package, rated for 32 V V_CEO, 100 mA I_C, and 350 mW P_C, commonly used in low-power switching and amplification stages of portable audio, sensor interface, and signal conditioning circuits.

For engineers reviewing the BCW60B datasheet, pinout, applications, or equivalent options, key selection criteria include DC current gain (h_FE = 70–220 at I_C = 10 µA–50 mA), f_T = 125 MHz, V_CE(sat) ≤ 0.55 V at I_C = 50 mA, noise figure = 6 dB, and SOT-23 thermal and layout compatibility.

Technical Context

The BCW60B operates as a medium-speed, low-noise NPN bipolar junction transistor optimized for linear amplification and digital switching in battery-powered systems. Its h_FE binning (70–220) ensures predictable gain across bias points, while f_T = 125 MHz supports audio-frequency and low-MHz signal handling.

Designed with epitaxial base construction, it delivers stable V_BE(on) = 0.55–0.75 V and low Cob = 4.5 pF, enabling clean turn-on/turn-off transitions (t_ON = 150 ns, t_OFF = 800 ns) with minimal Miller effect in common-emitter configurations.

Key Specifications

Pinout & Package

SOT-23 plastic surface-mount package with gull-wing leads; compact 2.9 mm × 1.3 mm footprint and 1.0 mm height, optimized for automated assembly and thermal dissipation in space-constrained PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BCW60B, BC846B offers greater voltage safety margin but reduced bandwidth, while MMBT3904 provides superior speed and wider gain range-both require validation of bias network stability due to differing h_FE curves and V_BE characteristics.

Availability

BCW60B is available at Aetrix Electronics and suitable for portable audio preamps, sensor signal conditioning, logic-level switching, and LED driver interfaces requiring stable component supply and long-lifecycle support.

Supply support for BCW60B 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

Fairchild Semiconductor was a U.S.-based semiconductor company specializing in power management, analog, and discrete components before its acquisition by ON Semiconductor in 2016.

The BCW60B belongs to Fairchild's legacy general-purpose bipolar transistor family, designed for cost-sensitive, low-power linear and switching applications in consumer and industrial electronics.

FAQ

What is the maximum collector-emitter voltage rating for BCW60B?

The BCW60B has a maximum collector-emitter voltage (V_CEO) rating of 32 V at T_A = 25°C. This value represents the upper limit of voltage that can be applied between collector and emitter with the base open before breakdown occurs. Exceeding this rating risks permanent device failure. The BCW60B must be operated within this limit in all circuit configurations, including transient conditions.

What is the DC current gain (h_FE) range specified for BCW60B?

The BCW60B exhibits a DC current gain (h_FE) ranging from 70 to 220, depending on test conditions: minimum 70 at I_C = 10 µA, 120 at I_C = 2 mA, and 220 at I_C = 50 mA (all at V_CE = 5 V or 1 V). This binned gain range reflects Fairchild's production sorting and must be accounted for in bias design to ensure consistent operation across units.

Is BCW60B suitable for high-frequency amplification applications?

The BCW60B has a current gain bandwidth product (f_T) of 125 MHz at I_C = 10 mA and V_CE = 5 V, making it suitable for audio-frequency amplification and low-MHz signal conditioning-but not for RF power or GHz-range applications. Its 4.5 pF output capacitance and 800 ns turn-off time further constrain use to sub-50 MHz small-signal stages where stability and noise performance are prioritized over raw speed.

What package type does BCW60B use, and what are its key mechanical features?

The BCW60B uses the SOT-23 surface-mount package, measuring 2.9 mm × 1.3 mm × 1.0 mm with gull-wing leads. It features a standardized 3-pin configuration (Base–Emitter–Collector) and is compatible with standard reflow soldering profiles. The compact size supports high-density PCB layouts, while the plastic body provides adequate thermal dissipation for its 350 mW power rating in still-air conditions.

How does BCW60B compare to BCW60C in terms of DC current gain?

The BCW60B is binned for h_FE = 70–220, whereas BCW60C is binned for h_FE = 100–310 at identical test conditions. This means BCW60C guarantees higher minimum gain across all operating points, particularly at I_C = 2 mA and I_C = 50 mA. Designers selecting BCW60B should verify bias networks function correctly across its lower gain range, especially in temperature-varying environments.