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onsemi BC546TF
- Part No.:
- BC546TF
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Datasheet:
-
BC546TF.pdf
- Description:
- TRANS NPN 65V 0.1A TO-92-3
- Quantity:
- Payment:
- Shipping:
Inventory:2,012
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Product details
Overview
BC546TF from ON Semiconductor is an NPN epitaxial silicon transistor optimized for general-purpose switching and linear amplification, with VCEO = 65 V, hFE = 110–220 (Class A), fT = 300 MHz, and TO-92 package. It operates reliably in low-noise audio preamplifiers, relay drivers, and signal conditioning stages where moderate voltage headroom and stable DC gain are required.
For engineers reviewing the BC546TF datasheet, pinout, applications, or equivalent options, key selection criteria include its 65 V collector-emitter breakdown rating, Class A hFE range, TO-92 mechanical compatibility, and suitability for discrete amplifier stages or digital logic interface circuits.
Technical Context
The BC546TF belongs to the BC546/547/548/549/550 family of through-hole NPN transistors fabricated using epitaxial silicon process technology. Its design emphasizes DC current gain stability across temperature and bias conditions, with guaranteed hFE classification (A/B/C) and specified VCE(sat) at two test points (IC = 10 mA/IB = 0.5 mA and IC = 100 mA/IB = 5 mA).
It features low output capacitance (Cob = 3.5–6.0 pF) and input capacitance (Cib = 9 pF), supporting high-frequency small-signal operation up to 300 MHz fT. The device is not rated for low-noise applications-those roles are assigned to BC549/BC550 variants per datasheet specification.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 65 V - Maximum safe DC voltage between collector and emitter before breakdown; enables use in 48 V supply rails or flyback snubbers. |
| hFE (Class A) | 110–220 - Confirmed DC current gain range at VCE = 5 V, IC = 2 mA; supports predictable biasing in fixed-gain amplifier designs. |
| fT | 300 MHz - Current gain bandwidth product at VCE = 5 V, IC = 10 mA; validates usability in RF front-end or wideband analog stages. |
| VCE(sat) | 90–250 mV - Saturation voltage at IC = 10 mA / IB = 0.5 mA; ensures low conduction loss in switching applications. |
| PC | 500 mW - Maximum continuous collector power dissipation at TA = 25 °C; defines thermal derating envelope for PCB layout. |
| Cob | 3.5–6.0 pF - Output capacitance at VCB = 10 V; impacts high-frequency impedance matching and stage isolation. |
Pinout & Package
BC546TF uses the standard TO-92 3-lead plastic package with straight lead configuration (JEDEC TO-92 compliant). Lead spacing is 0.2 inch (5.08 mm), and the device is supplied in tape-and-reel format (EIA-481-D compliant).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Collector) | Main current sink terminal | Connected to load or supply rail; carries full collector current; requires thermal consideration in high-duty-cycle switching. |
| 2 (Base) | Control input node | Receives drive current to modulate collector current; requires series resistor to limit IB and prevent saturation overshoot. |
| 3 (Emitter) | Current source reference terminal | Typically tied to ground or emitter degeneration resistor; establishes DC bias point and influences linearity in amplifier configurations. |
Key Features
| Feature | Design Value |
|---|---|
| High-voltage capability | VCEO = 65 V enables operation in industrial control interfaces and 24–48 V bus monitoring circuits without external clamping. |
| Stable DC current gain | hFE Class A (110–220) provides repeatable biasing in production-grade discrete amplifiers and sensor signal chains. |
| Low saturation voltage | VCE(sat) ≤ 250 mV at IC = 10 mA ensures efficient on-state performance in low-power logic-level switching. |
| High-frequency response | fT = 300 MHz supports use in IF amplifiers, oscillator buffers, and broadband pulse shaping networks. |
Applications
| Audio Preamp Stage | Relay Driver Circuit |
|---|---|
Use Scenario: Low-voltage, single-supply microphone preamplifier in consumer audio equipment. IC Role / Device Role / Timing Role: Small-signal NPN amplifier providing 20–40 dB voltage gain with minimal distortion. Use Value: Stable hFE and low VBE(on) (580–700 mV) enable consistent DC biasing and low-noise operation below 10 kHz. | Use Scenario: Driving 5–12 V coil relays from microcontroller GPIO pins. IC Role / Device Role / Timing Role: General-purpose switch controlling relay coil current up to 100 mA. Use Value: VCEO = 65 V withstands inductive kickback; VCE(sat) ≤ 250 mV minimizes power loss during sustained on-state. |
| Digital Logic Level Shifter | LED Current Regulator |
Use Scenario: Translating 3.3 V logic signals to 5 V or 12 V domains in mixed-voltage systems. IC Role / Device Role / Timing Role: Common-emitter level translator with defined turn-on/off thresholds. Use Value: Sharp VBE(on) transition and predictable hFE allow clean edge definition and fast propagation delay (< 100 ns). | Use Scenario: Constant-current LED driver for status indicators or backlighting in instrumentation panels. IC Role / Device Role / Timing Role: Linear current regulator using emitter-degeneration resistor. Use Value: 500 mW power rating and 150 °C junction temperature support continuous 60 mA LED current with passive heatsinking. |
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 |
|---|---|---|---|
| BC547BTF | VCEO = 45 V (vs. 65 V); same hFE Class B (200–450); identical TO-92 package and pinout. | Lower voltage rating limits use in >45 V supply environments; otherwise interchangeable in 5–24 V logic and signal paths. | Select BC547BTF only when system voltage remains ≤45 V and higher hFE improves loop gain margin. |
| PN2222A | VCEO = 40 V; hFE = 100–300; TO-92 package; higher IC = 800 mA max but lower fT ≈ 250 MHz. | Higher current capability suits heavier relay loads; reduced voltage headroom restricts use in 48 V telecom or industrial interfaces. | Choose PN2222A for higher collector current demands where 40 V rating suffices and gain-bandwidth trade-off is acceptable. |
Compared with BC546TF, BC547BTF offers higher hFE but sacrifices 20 V of collector-emitter breakdown margin, while PN2222A delivers greater current drive at the cost of voltage rating and high-frequency performance-making BC546TF optimal for 48 V–compatible, medium-gain, broadband signal tasks.
Availability
BC546TF is available at Aetrix Electronics and suitable for audio preamplifiers, relay driver circuits, and digital level-shifting applications requiring stable component supply, long-term obsolescence management, and JEDEC-compliant TO-92 mechanical fit.
Supply support for BC546TF 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, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The BC546TF belongs to ON Semiconductor's legacy general-purpose bipolar transistor product line, originally developed by Fairchild Semiconductor and maintained for broad compatibility in discrete amplifier, switching, and interface designs.
FAQ
What is the maximum collector-emitter voltage rating for BC546TF?
The BC546TF has a guaranteed VCEO (collector-emitter voltage) rating of 65 V at TA = 25 °C. This rating defines the absolute maximum DC voltage that can be applied between collector and emitter with the base open. Exceeding this value risks irreversible breakdown. Derating is required above 25 °C ambient per the datasheet's thermal curves.
Is BC546TF suitable for low-noise audio applications?
No, BC546TF is not specified for low-noise operation. The BC549 and BC550 variants in the same family are explicitly designated for low-noise applications, with noise figure ratings of 1.4–4.0 dB. BC546TF's noise figure is 2.0–10.0 dB under standard test conditions, making it appropriate for general amplification but not high-fidelity preamp stages.
What does the "TF" suffix indicate in BC546TF?
The "TF" suffix in BC546TF denotes tape-and-reel packaging in accordance with EIA-481-D standards. It specifies that the device is supplied in a plastic carrier tape with 2,000 units per reel, intended for automated SMT placement equipment-even though the TO-92 package itself is through-hole. This packaging format supports high-volume manufacturing logistics.
Can BC546TF replace BC547B in an existing design?
BC546TF can replace BC547B only if the circuit operates below 45 V collector-emitter voltage. BC546TF's VCEO = 65 V exceeds BC547B's 45 V rating, but its hFE range (110–220, Class A) is lower than BC547B's (200–450, Class B). Verify bias stability and gain margin; no PCB changes are needed due to identical TO-92 pinout and footprint.
What is the junction-to-ambient thermal resistance (RθJA) for BC546TF?
The BC546TF datasheet does not specify RθJA as a standalone parameter. However, its maximum power dissipation is rated at 500 mW at TA = 25 °C, with a maximum junction temperature of 150 °C. For PCB-level thermal design, assume RθJA ≈ 250 °C/W for standard TO-92 mounting on FR-4 with minimal copper; actual values depend on board layout, airflow, and solder pad area.
BC546TF 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):
- 65 V
- Vce Saturation (Max) @ Ib, Ic:
- 600mV @ 5mA, 100mA
- Current - Collector Cutoff (Max):
- 15nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 110 @ 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
BC546TF FAQ
1.How can I place an order for BC546TF through Aetrix?
Please submit a Request for Quotation (RFQ) for BC546TF 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 BC546TF reliable?
The price and inventory of BC546TF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC546TF is usually 5 days.
3.What payment methods are accepted for BC546TF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC546TF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC546TF?
BC546TF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC546TF 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 BC546TF?
For technical support, including BC546TF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC546TF requirements.
6.How does Aetrix verify that BC546TF is sourced from the original manufacturer or authorized distributors?
All BC546TF 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 BC546TF meets industry standards.
7.What is the process for return or replacement of BC546TF?
All BC546TF units undergo pre-shipment inspection (PSI). If there is an issue with BC546TF, 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 BC546TF part is unused and in its original packaging.
Return procedure for BC546TF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BC546TF Tags
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