onsemi BC547CG

Overview

BC547CG from onsemi is an NPN silicon general-purpose amplifier transistor in TO-92 package, rated for V_CEO = 45 V, I_C = 100 mA, and h_FE = 420–800 (at I_C = 10 mA, V_CE = 5 V). It delivers low V_CE(sat) = 0.25 V (at I_C = 10 mA, I_B = 1 mA) and f_T = 300 MHz, supporting linear amplification and switching in low-voltage analog and digital interface circuits.

For engineers reviewing the BC547CG datasheet, pinout, applications, or equivalent options, this page provides verified electrical parameters, TO-92 terminal mapping, real-world use cases in signal conditioning and load control, and two validated alternative transistors with documented h_FE, V_CEO, and thermal performance differences.

Technical Context

The BC547CG operates as a discrete bipolar junction transistor with fixed-emitter biasing capability and DC current gain optimized across three gain groups (A/B/C); the 'C' suffix denotes h_FE = 420–800 at I_C = 10 mA. Its f_T = 300 MHz enables audio-frequency amplification and medium-speed switching up to ~10 MHz with proper base drive.

Thermal design is constrained by R_JA = 200°C/W (free-air) and R_JC = 83.3°C/W, requiring heatsinking only above ~300 mW dissipation. The device supports operation from −55°C to +150°C junction temperature and exhibits V_BE(on) = 0.55–0.77 V (I_C = 2–10 mA), enabling predictable bias network design.

Key Specifications

Pinout & Package

BC547CG is housed in a Pb-free TO-92 (Case 29, Style 17) plastic package with 3.18–4.19 mm body width, 4.45–5.20 mm height, and 2.04–2.66 mm lead spacing. Leads are straight and tinned for through-hole soldering.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC547C and MPSA18, BC547CG uniquely combines RoHS-compliant packaging, 300 MHz f_T, and 0.25 V V_CE(sat)-making it optimal for space-constrained, high-fidelity, and environmentally regulated designs where gain stability and thermal efficiency are prioritized.

Availability

BC547CG is available at Aetrix Electronics and suitable for audio signal chains, microcontroller peripheral interfacing, sensor conditioning circuits, and industrial control modules requiring stable component supply and full RoHS compliance.

Supply support for BC547CG 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 specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.

The BC547CG belongs to onsemi's legacy BC546/547/548 amplifier transistor family, designed for cost-sensitive, high-volume general-purpose linear and switching applications in consumer, industrial, and communication equipment.

FAQ

What is the maximum collector-emitter voltage rating for BC547CG?

The BC547CG has a maximum collector-emitter voltage (V_CEO) rating of 45 V DC. This value is specified under test conditions of I_C = 1.0 mA and I_B = 0, and represents the highest voltage that can be applied between collector and emitter while keeping the transistor in the off state without risking avalanche breakdown. Exceeding 45 V may cause irreversible damage to the BC547CG.

What h_FE range is guaranteed for BC547CG at I_C = 10 mA and V_CE = 5 V?

The BC547CG guarantees a DC current gain (h_FE) range of 420 to 800 when tested at I_C = 10 mA and V_CE = 5 V, per the onsemi datasheet Rev. 8. This 'C' gain group ensures consistent amplification performance across production lots, enabling reliable bias network design without gain-dependent recalibration for the BC547CG.

Is BC547CG compatible with standard TO-92 footprints?

Yes, BC547CG uses the industry-standard TO-92 (Case 29, Style 17) package with pin 1 = collector, pin 2 = base, pin 3 = emitter, and mechanical dimensions matching JEDEC TO-226 specifications. Its lead pitch (2.54 mm nominal), body width (3.18–4.19 mm), and height (4.45–5.20 mm) ensure drop-in compatibility with existing TO-92 PCB layouts designed for BC547A/B/C variants or equivalent NPN transistors.

Does BC547CG meet RoHS requirements?

Yes, BC547CG is explicitly marked as Pb-free in the onsemi datasheet and ordering information, complying with EU RoHS Directive 2011/65/EU. The 'G' suffix in BC547CG denotes RoHS-compliant packaging, confirmed by onsemi's material declarations and Pb-free plating on all leads. This makes BC547CG suitable for environmentally regulated markets and medical/consumer products requiring lead-free assembly.

What is the typical transition frequency (f_T) of BC547CG and how does it affect circuit design?

The BC547CG has a typical transition frequency (f_T) of 300 MHz, measured at I_C = 10 mA and V_CE = 5 V. This parameter defines the frequency at which the transistor's small-signal current gain drops to unity, directly limiting usable bandwidth in common-emitter amplifier stages. For stable operation, designers typically limit closed-loop gain-bandwidth product to ≤ f_T/10, making BC547CG well-suited for audio and medium-speed digital interface applications up to ~10 MHz.