onsemi SS8050BBU

Overview

SS8050BBU from onsemi is an NPN epitaxial silicon transistor in TO-92-3 (case 135AN) package, rated for 1.5 A collector current, 25 V V_CEO, and 1 W power dissipation at 25°C. It delivers DC current gain (h_FE) of 85–160 at I_C = 100 mA, V_CE = 1 V, and is optimized for Class B push-pull audio amplifier stages in portable radios.

For engineers reviewing the SS8050BBU datasheet, pinout, applications, or equivalent options, key selection criteria include its V_CEO/I_C rating, h_FE classification band (B), saturation voltage (V_CE(sat) ≤ 0.5 V at I_C = 800 mA), thermal resistance (R_JA = 125 °C/W), and Pb-free RoHS-compliant packaging.

Technical Context

This discrete NPN bipolar junction transistor operates in linear or switching modes with verified breakdown voltages: V_CBO = 40 V, V_CEO = 25 V, and V_EBO = 6 V. Its f_T = 100 MHz at V_CE = 10 V, I_C = 50 mA supports mid-frequency amplification tasks.

Thermal performance is defined by R_JA = 125 °C/W on standard FR-4 PCB (76 mm × 114 mm × 1.57 mm), with 8 mW/°C derating above 25°C ambient. Output capacitance C_ob = 9.0 pF at V_CB = 10 V enables stable operation in RF-coupled preamp stages.

Key Specifications

Pinout & Package

SS8050BBU uses the TO-92-3 package (case 135AN), a through-hole plastic package with 3 leads, 4.825 mm × 4.76 mm footprint, and standardized leadform for manual or wave soldering.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SS8050CBU and MMBT3904LT1G, the SS8050BBU provides the optimal balance of 1.5 A current handling, TO-92 manufacturability, and B-bin h_FE consistency-making it preferred for cost-sensitive, through-hole audio and motor drive applications where thermal margin and gain predictability are critical.

Availability

SS8050BBU is available at Aetrix Electronics and suitable for portable audio amplifiers, DC motor drivers, LED current sinks, and logic-level translators requiring stable component supply and long-term industrial availability.

Supply support for SS8050BBU 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The SS8050BBU belongs to onsemi's general-purpose bipolar transistor product line, engineered for reliable, cost-effective amplification and switching in consumer and industrial analog systems.

FAQ

What is the h_FE range for SS8050BBU?

The SS8050BBU is binned to the "B" classification, with DC current gain (h_FE) specified from 85 to 160 when measured at V_CE = 1 V and I_C = 100 mA. This range is confirmed in the official onsemi datasheet (Rev. 2, February 2022) and applies specifically to the SS8050BBU variant-not the broader SS8050 family. Designers should verify bias networks accommodate this full span.

Is SS8050BBU pin-compatible with other SS8050 variants like SS8050CBU?

Yes, SS8050BBU is mechanically and electrically pin-compatible with all SS8050 variants-including SS8050CBU and SS8050DBU-because they share the identical TO-92-3 (case 135AN) package and terminal assignment (E-B-C). The only differences are h_FE binning and top-mark code ("S8050B"); no PCB changes are required when substituting within the same package type.

What is the maximum power dissipation for SS8050BBU at 70°C ambient?

At 70°C ambient, SS8050BBU's maximum power dissipation is derated from 1 W at 25°C by 8 mW/°C. The allowable reduction is (70 − 25) × 8 mW = 360 mW, so P_D(max) = 1000 mW − 360 mW = 640 mW. This value assumes standard FR-4 PCB conditions per onsemi's thermal characterization note.

Does SS8050BBU support audio frequency amplification up to 20 kHz?

Yes, SS8050BBU supports full-audio-band amplification up to 20 kHz. With f_T = 100 MHz and verified gain flatness in typical performance curves (Figure 2), its unity-gain bandwidth far exceeds audio requirements. When used in Class B push-pull configuration-as highlighted in the datasheet's "2 W Output Amplifier" feature-it delivers low-distortion amplification across the audible spectrum.

Can SS8050BBU be used as a direct replacement for BC547 in existing designs?

No, SS8050BBU is not a direct replacement for BC547. While both are NPN transistors, SS8050BBU has higher I_C (1.5 A vs. 100 mA), higher P_D (1 W vs. 500 mW), and different h_FE distribution. Substituting without circuit review risks overdriving base networks or exceeding safe operating area limits in low-power BC547 applications.