onsemi BC548CTFR

Overview

BC548CTFR from ON Semiconductor is an NPN epitaxial silicon transistor optimized for general-purpose switching and low-noise amplification in consumer and industrial electronics. It features V_CEO = 30 V, I_C = 100 mA, h_FE = 420–800 (Class C), f_T = 300 MHz, and TO-92 package - enabling use in audio preamps, sensor signal conditioning, and digital logic interface circuits.

For engineers reviewing the BC548CTFR datasheet, pinout, applications, or equivalent options, key selection criteria include DC current gain classification, saturation voltage at defined drive conditions, noise figure at 1 kHz, output capacitance, and compatibility with TO-92 PCB footprints and tape-and-reel automation.

Technical Context

This device belongs to the BC546–BC550 family of through-hole NPN transistors, sharing identical TO-92 packaging and pinout but differing in voltage ratings and h_FE bins. BC548CTFR is specifically rated for V_CEO = 30 V and V_CBO = 30 V, with h_FE classified as Class C (420–800 at V_CE = 5 V, I_C = 2 mA).

It delivers 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, and exhibits Cob = 3.5–6.0 pF at V_CB = 10 V - supporting stable operation in medium-frequency analog and fast-switching digital applications.

Key Specifications

Pinout & Package

BC548CTFR is housed in a JEDEC TO-92 plastic package with straight leads, compatible with standard through-hole assembly and automated tape-and-reel pick-and-place. Pin 1 is Collector, Pin 2 is Base, Pin 3 is Emitter - verified per Fairchild/ON Semiconductor mechanical drawings and ordering information.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC547CTFR and 2N3904TA, BC548CTFR offers the lowest V_CEO rating but highest guaranteed h_FE bin among common TO-92 NPNs - making it optimal for low-power, high-gain analog stages where voltage headroom is constrained.

Availability

BC548CTFR is available at Aetrix Electronics and suitable for audio preamplifiers, sensor signal conditioners, digital logic interfaces, and relay drivers requiring stable component supply across prototyping, pilot production, and long-lifecycle industrial programs.

Supply support for BC548CTFR 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 (formerly Fairchild Semiconductor) is a global leader in energy-efficient semiconductor solutions, serving automotive, industrial, cloud computing, and consumer markets with discrete, analog, and power ICs.

The BC548CTFR belongs to ON Semiconductor's legacy general-purpose bipolar transistor product line - designed for cost-effective, reliable signal amplification and switching in non-critical, non-automotive applications with wide ambient temperature tolerance.

FAQ

What is the maximum collector-emitter voltage rating for BC548CTFR?

The BC548CTFR has a maximum collector-emitter voltage (V_CEO) rating of 30 V, as specified in the Absolute Maximum Ratings table of the official ON Semiconductor datasheet. This value defines the upper limit of voltage that can be applied between collector and emitter while keeping the base open. Exceeding this rating risks permanent device breakdown. Designers should maintain at least 20% derating margin - i.e., limit operating V_CE to ≤24 V - for long-term reliability in variable-temperature environments.

Does BC548CTFR have a documented noise figure specification?

Yes, BC548CTFR has a documented noise figure (NF) of 2.0–10.0 dB at V_CE = 5 V, I_C = 200 μA, f = 1 kHz, and R_G = 2 kΩ, per the Electrical Characteristics table. This specification applies directly to the BC548 variant within the BC546–BC550 family. The BC548CTFR inherits this value as a Class C device, making it suitable for low-noise preamplifier stages where signal-to-noise ratio is critical - unlike BC549/BC550, which offer lower NF but different voltage ratings.

What does the "TFR" suffix mean in BC548CTFR?

The "TFR" suffix in BC548CTFR indicates tape-and-reel packaging in TO-92 format, as confirmed in the Ordering Information table of the ON Semiconductor datasheet. "T" stands for tape, "F" for reel, and "R" for the standard carrier specification compliant with EIA-481. This packaging enables automated placement using pick-and-place machines calibrated for through-hole components, distinguishing BC548CTFR from bulk (BU) or ammo (TA) variants - all sharing identical electrical and thermal specifications.

Is BC548CTFR pin-compatible with BC547CTFR and BC558?

Yes, BC548CTFR is pin-compatible with BC547CTFR and BC558: all three use the JEDEC TO-92 package with identical pinout - Pin 1 = Collector, Pin 2 = Base, Pin 3 = Emitter. This mechanical and electrical compatibility is explicitly confirmed in the Physical Dimensions section and ordering tables. However, BC558 is a PNP complement with inverted polarity, so circuit topology must be adjusted accordingly; BC547CTFR shares the same h_FE bin but offers higher V_CEO (45 V vs. 30 V).

What is the DC current gain (h_FE) range for BC548CTFR at typical operating conditions?

The BC548CTFR is classified as Class C, with a guaranteed DC current gain (h_FE) range of 420–800 when measured at V_CE = 5 V and I_C = 2 mA, per the h_FE Classification table. This binning is consistent across all BC548 variants including BC548CTFR. Designers should use the minimum value (420) for worst-case bias calculations and verify stability across temperature using the Typical Performance Characteristics curves in the datasheet.