onsemi BC548CTF

Overview

BC548CTF from ON Semiconductor is an NPN epitaxial silicon transistor designed for general-purpose switching and low-noise amplification in discrete analog circuits. It features V_CEO = 30 V, I_C = 100 mA, h_FE = 420–800 (Class C), f_T = 300 MHz, and V_BE(on) = 580–700 mV at I_C = 2 mA - enabling use in audio preamps, sensor interface stages, and digital logic level translation.

For engineers reviewing the BC548CTF datasheet, pinout, applications, or equivalent options, key selection criteria include its TO-92 package compatibility, Class C h_FE gain binning, low-noise performance (NF = 2.0–10.0 dB), saturation voltage behavior under 10 mA/100 mA drive, and junction temperature rating of 150°C.

Technical Context

The BC548CTF operates as a single NPN bipolar junction transistor with fixed emitter-base-collector topology and no integrated biasing or protection circuitry. Its DC current gain is binned to Class C (h_FE = 420–800) per JEDEC JESD22-A108, and its small-signal RF performance is characterized at V_CE = 5 V, I_C = 10 mA, f = 100 MHz.

It exhibits V_CE(sat) ≤ 250 mV at I_C = 10 mA / I_B = 0.5 mA and ≤ 600 mV at I_C = 100 mA / I_B = 5 mA, with input capacitance C_ib = 9 pF and output capacitance C_ob = 3.5–6.0 pF at V_CB = 10 V - confirming suitability for audio-frequency amplification and medium-speed switching up to ~10 MHz.

Key Specifications

Pinout & Package

BC548CTF is housed in a standard JEDEC TO-92 plastic package with straight leads (bulk/ammo/tape-and-reel variants). The package measures 4.6 mm × 3.3 mm × 4.0 mm and is lead-free and RoHS-compliant per ON Semiconductor's product change notification PCN-150101.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC547CTA and 2N3904TA, BC548CTF offers superior low-noise performance and tighter h_FE control for analog gain stages, while maintaining full TO-92 mechanical compatibility - making it optimal for audio and precision sensor interfaces where gain predictability and SNR matter.

Availability

BC548CTF is available at Aetrix Electronics and suitable for audio preamplifiers, sensor signal conditioners, and digital logic interface circuits requiring stable component supply, long-term manufacturability, and JEDEC-standard packaging.

Supply support for BC548CTF 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 management, analog, sensors, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The BC548CTF belongs to ON Semiconductor's legacy general-purpose bipolar transistor product line - originally developed by Fairchild and maintained for broad compatibility in cost-sensitive, high-volume discrete analog and switching applications.

FAQ

What is the maximum collector-emitter voltage rating for BC548CTF?

The BC548CTF has a maximum collector-emitter voltage (V_CEO) rating of 30 V, as specified in the absolute maximum ratings table. This value is confirmed across all official ON Semiconductor documentation for the BC548 series and applies directly to the BC548CTF variant. Exceeding this voltage risks avalanche breakdown and permanent device damage, especially under sustained DC or repetitive pulse conditions.

Does BC548CTF have a guaranteed h_FE range, and what is it?

Yes, BC548CTF is binned to Class C with a guaranteed DC current gain (h_FE) range of 420 to 800 at V_CE = 5 V and I_C = 2 mA. This classification is explicitly defined in the "h_FE Classification" table of the BC546–BC550 datasheet and applies to all BC548C-marked variants including BC548CTF. It enables reliable gain prediction without post-production testing.

What is the noise figure of BC548CTF, and under what conditions is it measured?

The BC548CTF has a noise figure (NF) of 2.0–10.0 dB, measured at V_CE = 5 V, I_C = 200 μA, f = 1 kHz, and R_G = 2 kΩ. This specification is documented in the Electrical Characteristics table for the BC546–BC550 family and applies to BC548 variants. It reflects the device's suitability for low-level analog amplification where signal integrity is critical.

Is BC548CTF compatible with standard TO-92 PCB footprints?

Yes, BC548CTF uses a JEDEC-standard TO-92 package with straight leads and conforms to the physical dimensions shown in Figure 7 of the BC546–BC550 datasheet. Its pin 1–2–3 layout (collector–base–emitter) matches industry-standard TO-92 footprints, ensuring mechanical and soldering compatibility with existing designs using BC546/BC547/BC549/BC550 or 2N3904 equivalents.

What is the maximum power dissipation of BC548CTF, and how does ambient temperature affect it?

The BC548CTF has a maximum collector power dissipation (P_C) of 500 mW at T_A = 25°C. Above this ambient temperature, power must be linearly derated at 4.0 mW/°C - meaning usable power drops to 300 mW at 75°C ambient. This derating is defined in the Absolute Maximum Ratings section and applies to all TO-92-packaged variants including BC548CTF.