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Home > Products > Discrete Semiconductor Products > Transistors > Bipolar (BJT) > Single Bipolar Transistors

onsemi BC547CTF

Name: BC547CTF
Brand: onsemi
SKU: BC547CTF
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BC547CTF

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-226-3, TO-92-3 (TO-226AA) Formed Leads

Datasheet:: BC547CTF.pdf

Description:: TRANS NPN 45V 0.1A TO-92-3

Quantity:: RFQ Add To RFQ list

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Product details

Overview

BC547CTF from ON Semiconductor is an NPN epitaxial silicon transistor in TO-92 package, rated for 45 V V_CEO, 100 mA I_C, and 500 mW P_C, with h_FE range 420–800 (Class C), used in general-purpose switching and low-noise amplification circuits.

For engineers reviewing the BC547CTF datasheet, pinout, applications, or equivalent options, key selection criteria include DC current gain classification, saturation voltage at defined drive conditions, noise figure in audio preamp use, and TO-92 lead form compatibility with manual or automated assembly.

Technical Context

This device operates as a discrete bipolar junction transistor with fixed emitter-base and collector-base junctions, supporting linear amplification when biased in the active region and fast switching when driven into saturation or cutoff. Its performance is characterized by specified h_FE, V_CE(sat), V_BE(sat), and f_T = 300 MHz at I_C = 10 mA.

The BC547CTF belongs to the BC546–BC550 family sharing identical TO-92 packaging and pinout but differing in voltage ratings and h_FE bins: BC547 variants have V_CEO = 45 V and V_CBO = 50 V, distinguishing them from BC546 (65 V/80 V) and BC548 (30 V/30 V).

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	45 V - Maximum allowable collector-emitter voltage before breakdown; sets upper rail limit in switching or amplifier stages.
I_C (DC)	100 mA - Continuous collector current rating; defines maximum load-handling capability in relay drivers or LED switches.
P_C	500 mW - Total power dissipation at T_A = 25°C; determines thermal derating requirements on PCB.
h_FE (Class C)	420–800 - DC current gain range at V_CE = 5 V, I_C = 2 mA; enables stable biasing in low-signal amplifiers without excessive base drive.
V_CE(sat)	250–600 mV at I_C = 100 mA, I_B = 5 mA - Low saturation voltage reduces conduction loss in switch-mode applications.
f_T	300 MHz - Current gain-bandwidth product at V_CE = 5 V, I_C = 10 mA; supports RF amplification up to ~100 MHz with gain margin.
NF	2.0–10.0 dB at V_CE = 5 V, I_C = 200 μA, f = 1 kHz - Noise figure suitable for microphone preamplifiers and sensor signal conditioning.

Pinout & Package

BC547CTF uses the standard TO-92 3-lead plastic package with straight leads (JEDEC TO-92 compliant), designed for through-hole mounting and compatible with tape-and-reel automated placement per ordering code "TF".

Pin/Terminal	Circuit Role	Design Meaning
1 (Collector)	Current sink terminal	Connected to load or supply rail in common-emitter configuration; handles full output current path.
2 (Base)	Control input terminal	Receives bias current to regulate collector current; requires current-limiting resistor in most driver circuits.
3 (Emitter)	Current source terminal	Typically tied to ground or negative rail; provides reference node for bias stability and signal return.

Key Features

Feature	Design Value
Switching & amplification dual use	Validated by V_CE(sat) ≤ 600 mV at high drive and h_FE ≥ 420 - enables single-part reuse across digital logic interfaces and analog gain stages.
Class C h_FE bin	420–800 gain range - ensures predictable bias point stability in emitter-follower or common-emitter amplifiers without trimming.
Low noise figure	2.0–10.0 dB at audio frequencies - supports high-SNR front-end design in electret microphone amplifiers and sensor signal chains.
TO-92 tape-and-reel packaging	"TF" suffix denotes EIA-481-compliant carrier tape - enables direct integration into SMT-style pick-and-place lines despite through-hole form factor.

Applications

Audio Pre-amplifier	LED Driver
Use Scenario: Amplifying weak signals from electret microphones or piezoelectric sensors before ADC sampling. IC Role / Device Role / Timing Role: Discrete NPN transistor configured as common-emitter amplifier with emitter degeneration for linearity. Use Value: 2.0–10.0 dB noise figure and 420–800 h_FE enable >60 dB SNR in battery-powered voice recorders without external op-amps.	Use Scenario: Driving indicator or status LEDs in industrial control panels and consumer appliances. IC Role / Device Role / Timing Role: Low-side switch with base resistor limiting I_B to ensure saturation at I_C ≤ 100 mA. Use Value: V_CE(sat) ≤ 600 mV at I_C = 100 mA minimizes power loss and self-heating during continuous LED operation.
Relay Driver	Signal Level Shifting
Use Scenario: Interfacing microcontroller GPIO pins to 5–12 V relay coils in home automation and PLC I/O modules. IC Role / Device Role / Timing Role: Digital switch operating in saturation/cutoff with flyback diode protection. Use Value: 45 V V_CEO safely accommodates relay coil back-EMF spikes up to 40 V, preventing unintended turn-on or breakdown.	Use Scenario: Translating 3.3 V logic outputs to 5 V TTL-compatible inputs in mixed-voltage digital systems. IC Role / Device Role / Timing Role: Common-emitter level shifter with pull-up resistor on collector. Use Value: Fast f_T = 300 MHz and low C_ob = 3.5–6.0 pF support clean edge transitions up to 10 MHz without added propagation delay.

Audio Pre-amplifier

LED Driver

Use Scenario: Amplifying weak signals from electret microphones or piezoelectric sensors before ADC sampling.

IC Role / Device Role / Timing Role: Discrete NPN transistor configured as common-emitter amplifier with emitter degeneration for linearity.

Use Value: 2.0–10.0 dB noise figure and 420–800 h_FE enable >60 dB SNR in battery-powered voice recorders without external op-amps.

Use Scenario: Driving indicator or status LEDs in industrial control panels and consumer appliances.

IC Role / Device Role / Timing Role: Low-side switch with base resistor limiting I_B to ensure saturation at I_C ≤ 100 mA.

Use Value: V_CE(sat) ≤ 600 mV at I_C = 100 mA minimizes power loss and self-heating during continuous LED operation.

Relay Driver

Signal Level Shifting

Use Scenario: Interfacing microcontroller GPIO pins to 5–12 V relay coils in home automation and PLC I/O modules.

IC Role / Device Role / Timing Role: Digital switch operating in saturation/cutoff with flyback diode protection.

Use Value: 45 V V_CEO safely accommodates relay coil back-EMF spikes up to 40 V, preventing unintended turn-on or breakdown.

Use Scenario: Translating 3.3 V logic outputs to 5 V TTL-compatible inputs in mixed-voltage digital systems.

IC Role / Device Role / Timing Role: Common-emitter level shifter with pull-up resistor on collector.

Use Value: Fast f_T = 300 MHz and low C_ob = 3.5–6.0 pF support clean edge transitions up to 10 MHz without added propagation delay.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BC547C (TO-92, Ammo)	Same electrical specs and h_FE bin, but supplied in ammo pack instead of tape-and-reel.	No difference in circuit function; only packaging format differs for manual vs. automated assembly.	Select BC547CTF for SMT-line compatibility; choose BC547C for hand-soldering or small-batch prototyping.
PN2222A	Higher V_CEO = 40 V (vs. 45 V), lower h_FE min = 100, and wider V_CE(sat) range (300–1000 mV at same I_C/I_B).	Less suitable for low-noise audio due to higher NF (~15 dB); acceptable for basic switching where gain tolerance is relaxed.	Use PN2222A only if BC547CTF supply is constrained and circuit can tolerate reduced gain consistency and higher saturation loss.

Compared with BC547C and PN2222A, BC547CTF offers tighter h_FE control (420–800), lower typical V_CE(sat), and tape-and-reel readiness - making it optimal for production-grade audio preamps and automated LED driver assembly where parametric consistency and placement efficiency matter.

Availability

BC547CTF is available at Aetrix Electronics and suitable for audio pre-amplification, LED driving, relay interfacing, and logic-level translation requiring stable component supply and TO-92 tape-and-reel compatibility.

Supply support for BC547CTF 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 power management, analog, sensor, and discrete solutions for automotive, industrial, and consumer markets.

The BC547CTF belongs to ON Semiconductor's legacy general-purpose transistor portfolio, originally developed by Fairchild and maintained for cost-sensitive, high-volume linear and switching applications where reliability and parametric consistency are essential.

FAQ

What is the pinout configuration of BC547CTF?

The BC547CTF uses the standard TO-92 pinout: Pin 1 is Collector, Pin 2 is Base, and Pin 3 is Emitter when viewing the flat side of the package with leads pointing downward and left-to-right. This configuration is consistent across all BC546–BC550 series devices and verified in the official ON Semiconductor datasheet Rev. 1.1.1.

What does the "TF" suffix mean in BC547CTF?

"TF" indicates tape-and-reel packaging per EIA-481 standards, with straight leads and JEDEC TO-92 compliance. The BC547CTF is supplied in carrier tape optimized for automated pick-and-place equipment, distinguishing it from bulk (BU) or ammo (TA) variants while retaining identical electrical and thermal specifications.

Is BC547CTF suitable for audio amplifier applications?

Yes, BC547CTF is suitable for low-noise audio pre-amplifier stages due to its Class C h_FE (420–800), low noise figure (2.0–10.0 dB at 1 kHz), and stable V_BE(on) (580–700 mV). It is commonly used in electret microphone biasing and sensor signal conditioning where SNR and gain predictability are critical.

How does BC547CTF differ from BC547BTF?

BC547CTF and BC547BTF share identical TO-92 package, pinout, and absolute maximum ratings, but differ in h_FE classification: BC547CTF is Class C (420–800), while BC547BTF is Class B (200–450). This affects bias stability and gain variation in amplifier designs - BC547CTF provides higher and tighter gain control.

Can BC547CTF replace BC547C in existing designs?

Yes, BC547CTF is a direct functional and mechanical replacement for BC547C, with identical electrical parameters, TO-92 footprint, and pinout. The only difference is packaging format (tape-and-reel vs. ammo), so no schematic or layout changes are needed - only feed mechanism adjustment on assembly lines.

BC547CTF Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-226-3, TO-92-3 (TO-226AA) Formed Leads

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 100 mA

Voltage - Collector Emitter Breakdown (Max):: 45 V

Vce Saturation (Max) @ Ib, Ic:: 600mV @ 5mA, 100mA

Current - Collector Cutoff (Max):: 15nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 420 @ 2mA, 5V

Power - Max:: 500 mW

Frequency - Transition:: 300MHz

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92-3

BC547CTF FAQ

1.How can I place an order for BC547CTF through Aetrix?

Please submit a Request for Quotation (RFQ) for BC547CTF on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for BC547CTF reliable?

The price and inventory of BC547CTF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC547CTF is usually 5 days.

3.What payment methods are accepted for BC547CTF?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC547CTF transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BC547CTF?

BC547CTF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BC547CTF order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for BC547CTF?

For technical support, including BC547CTF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC547CTF requirements.

6.How does Aetrix verify that BC547CTF is sourced from the original manufacturer or authorized distributors?

All BC547CTF products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that BC547CTF meets industry standards.

7.What is the process for return or replacement of BC547CTF?

All BC547CTF units undergo pre-shipment inspection (PSI). If there is an issue with BC547CTF, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The BC547CTF part is unused and in its original packaging.

Return procedure for BC547CTF:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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