onsemi BCW66G_D87Z

Overview

BCW66G_D87Z from ON Semiconductor is an NPN general-purpose bipolar junction transistor (BJT) designed for amplifier and switching applications up to 500 mA collector current. It features a V_CEO of 45 V, V_CBO of 75 V, h_FE ranging from 50 to 400 (depending on bias), f_T of 100 MHz, and SOT-23 surface-mount package.

For engineers reviewing the BCW66G_D87Z datasheet, pinout, applications, or equivalent options, key selection considerations include DC current gain linearity across operating currents, saturation voltage at high drive levels, thermal resistance (357 °C/W), noise figure (10 dB at 1 kHz), and compatibility with low-voltage, medium-current analog and digital interface stages.

Technical Context

The BCW66G_D87Z operates as a discrete NPN BJT with fixed emitter-base and collector-base junction structures optimized for general-purpose linear amplification and saturated switching. Its process (Fairchild Process 13) ensures consistent h_FE distribution and low C_ibo (80 pF) for stable high-frequency small-signal gain.

Thermal design is constrained by its SOT-23 package's R_θJA of 357 °C/W and 350 mW total power dissipation at 25°C - derating to 2.8 mW/°C above ambient. Junction temperature must remain ≤150°C under all operating conditions, including pulsed loads.

Key Specifications

Pinout & Package

SOT-23 plastic surface-mount package (3-pin, standard footprint). Dimensions: 2.90 × 1.30 × 1.00 mm (L × W × H), with gull-wing leads and moisture sensitivity level (MSL) 1 per JEDEC J-STD-020.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BCW66G_D87Z, BC847B trades current capability for precision gain, while MMBT3904LT1G emphasizes speed over analog linearity - making BCW66G_D87Z the preferred choice for medium-current, wide-operating-point amplifier and switch roles requiring balanced f_T, h_FE, and thermal robustness.

Availability

BCW66G_D87Z is available at Aetrix Electronics and suitable for industrial sensor interfaces, audio preamplifier stages, and logic-level switch drivers requiring stable component supply and long-term manufacturability.

Supply support for BCW66G_D87Z 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, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The BCW66G_D87Z belongs to ON Semiconductor's legacy general-purpose BJT product line, originally developed by Fairchild Semiconductor for cost-sensitive, medium-performance analog and interface applications.

FAQ

What is the maximum continuous collector current rating for BCW66G_D87Z?

The BCW66G_D87Z has a maximum continuous collector current (I_C) rating of 1 A at T_C = 25°C. However, practical operation at this level requires substantial PCB copper area and thermal management due to its 357 °C/W junction-to-ambient thermal resistance. For reliable long-term use at >500 mA, derating and heatsinking are strongly advised. The BCW66G_D87Z datasheet specifies 500 mA as the typical upper limit for general-purpose amplifier applications.

Does BCW66G_D87Z support high-frequency signal amplification?

Yes, BCW66G_D87Z supports high-frequency signal amplification with a current-gain bandwidth product (f_T) of 100 MHz under standard test conditions (V_CE = 10 V, I_C = 20 mA). This enables usable small-signal gain up to approximately 10–20 MHz depending on bias point and circuit topology. Its 12 pF output capacitance and 80 pF input capacitance must be accounted for in matching networks. The BCW66G_D87Z is not intended for RF power amplification but performs well in wideband audio and medium-speed pulse amplification.

What is the pin configuration of BCW66G_D87Z in the SOT-23 package?

The BCW66G_D87Z uses the standard SOT-23 pinout: Pin 1 is Base, Pin 2 is Emitter, and Pin 3 is Collector. The top-mark "EG" identifies the device orientation. This configuration is consistent across Fairchild/ON Semiconductor's BCW66 family and matches JEDEC MO-203AB mechanical specifications. No alternate pinouts or variants exist for the BCW66G_D87Z; the pin mapping is validated in the original August 2002 Rev. A1 datasheet and confirmed on ON Semiconductor's official product page.

How does BCW66G_D87Z compare to BCW66H in terms of DC current gain?

The BCW66G_D87Z has a minimum h_FE of 50 at I_C = 100 µA and 110 at I_C = 10 mA, whereas BCW66H is binned for higher gain - typically h_FE ≥ 200 at I_C = 10 mA. Both share identical voltage ratings, thermal specs, and package. The BCW66G_D87Z is selected when moderate gain with broader operating range is preferred; BCW66H suits applications demanding guaranteed high gain at low currents. The BCW66G_D87Z datasheet explicitly defines its h_FE bins and confirms no overlap with H-grade performance.

Is BCW66G_D87Z suitable for automotive applications?

The BCW66G_D87Z is not qualified to AEC-Q101 or automotive-grade reliability standards. While its operating junction temperature range (−55°C to +150°C) meets automotive ambient extremes, it lacks automotive-specific qualification testing (e.g., HTOL, TC, ESD), lot traceability, and PPAP documentation. ON Semiconductor lists it under general-purpose commercial/industrial categories. For automotive use, designers should select AEC-Q101-qualified equivalents such as NSS121002MR6T1G. The BCW66G_D87Z remains appropriate for industrial and consumer equipment where full automotive qualification is not required.