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onsemi BC549BTAR
- Part No.:
- BC549BTAR
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Datasheet:
-
BC549BTAR.pdf
- Description:
- TRANS NPN 30V 0.1A TO-92-3
- Quantity:
- Payment:
- Shipping:
Inventory:3,384
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Product details
Overview
BC549BTAR from ON Semiconductor is an NPN epitaxial silicon transistor optimized for low-noise amplification and general-purpose switching in analog signal paths, with VCEO = 30 V, hFE = 200–450 (Class B), fT = 300 MHz, and VBE(on) = 580–700 mV at IC = 2 mA - widely used in audio preamplifiers, sensor interface stages, and discrete gain blocks.
For engineers reviewing the BC549BTAR datasheet, pinout, applications, or equivalent options, key selection criteria include its low-noise figure (1.4–4.0 dB at 30–15 kHz), TO-92 package compatibility, Class B hFE range, and VCEO/VCBO ratings suitable for 24 V rail systems and battery-powered instrumentation.
Technical Context
The BC549BTAR operates as a discrete bipolar junction transistor with fixed emitter-base-collector topology, supporting linear amplification and saturated switching modes. Its low-noise design targets audio-frequency small-signal amplification, with noise figure specified under VCE = 5 V, IC = 200 μA, RG = 2 kΩ, and bandwidth 30–15,000 Hz.
It belongs to the BC546–BC550 family sharing TO-92 packaging, JEDEC-compliant pinout (E-B-C), and complementary PNP counterparts (BC556–BC560). Device classification is Class B (hFE = 200–450), distinguishing it from BC549C (420–800) and BC549A (110–220).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 30 V - maximum collector-emitter voltage before breakdown; supports operation up to 24 V DC rails with safety margin. |
| hFE (Class B) | 200–450 - DC current gain range at VCE = 5 V, IC = 2 mA; enables predictable biasing in common-emitter amplifier designs. |
| fT | 300 MHz - unity-gain frequency at VCE = 5 V, IC = 10 mA; sufficient for audio and low-MHz signal conditioning. |
| Noise Figure | 1.4–4.0 dB - measured at VCE = 5 V, IC = 200 μA, RG = 2 kΩ, 30–15 kHz; qualifies for microphone preamp and sensor front-end use. |
| PC | 500 mW - maximum power dissipation at TA = 25°C; limits continuous collector current to ~100 mA in ambient conditions. |
| VBE(on) | 580–700 mV - base-emitter turn-on voltage at VCE = 5 V, IC = 2 mA; defines required drive level for reliable conduction. |
Pinout & Package
BC549BTAR is housed in a standard TO-92 plastic package (JEDEC TO-92 compliant), with straight leads and molded body. Dimensions conform to Figure 7 and Figure 8 of the datasheet. Pin identification is unambiguous: viewed from flat side with leads down, left-to-right is Emitter (1), Base (2), Collector (3).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Left) | Emitter | Current exit path; referenced to ground or negative rail in common-emitter configuration; sets bias point with base resistor network. |
| 2 (Center) | Base | Control terminal; requires ~580–700 mV forward bias and microamp-level current to drive 10–100 mA collector current. |
| 3 (Right) | Collector | Current input node; connected to load or supply rail; sustains up to 30 V VCEO and 500 mW dissipation. |
Key Features
| Feature | Design Value |
|---|---|
| Low-noise amplification | 1.4–4.0 dB noise figure in 30–15 kHz band enables high-fidelity audio and precision sensor signal conditioning without added op-amp complexity. |
| Class B hFE binning | Guaranteed 200–450 DC current gain ensures consistent bias stability across production lots in amplifier and switch designs. |
| TO-92 mechanical compatibility | Standardized 3-lead through-hole footprint allows drop-in replacement with BC546–BC550 series and legacy Fairchild/ON parts. |
| Complementary PNP pairing | Designed to match BC556–BC560 family for push-pull output stages, differential pairs, and balanced amplifier topologies. |
Applications
| Audio Preamp Stage | Sensor Signal Amplifier |
|---|---|
Use Scenario: Low-level microphone or piezoelectric sensor signal amplification prior to ADC sampling in portable audio recorders. IC Role / Device Role / Timing Role: Discrete NPN transconductance amplifier operating in common-emitter configuration with emitter degeneration. Use Value: 1.4–4.0 dB noise figure preserves SNR at sub-mV input levels; Class B hFE ensures stable gain without thermal runaway. | Use Scenario: Amplifying millivolt-level outputs from thermocouples or strain gauges in industrial monitoring modules. IC Role / Device Role / Timing Role: First-stage gain element in instrumentation front-end, biased for low quiescent current and high linearity. Use Value: VCEO = 30 V accommodates 24 V system rails; fT = 300 MHz provides ample bandwidth for <100 kHz sensor signals. |
| Discrete Switch Driver | LED Current Regulator |
Use Scenario: Driving relay coils or small solenoids from microcontroller GPIO pins in PLC I/O modules. IC Role / Device Role / Timing Role: Saturated NPN switch with base current limiting, interfacing logic-level control to inductive loads. Use Value: VCE(sat) ≤ 250 mV at IC = 10 mA minimizes power loss; 500 mW PC supports intermittent 100 mA peak loads. | Use Scenario: Constant-current LED driver for status indicators or backlighting in medical handheld devices. IC Role / Device Role / Timing Role: Linear current source using emitter resistor feedback and fixed base bias. Use Value: Tight hFE binning (200–450) enables predictable current regulation across temperature; TO-92 allows manual assembly and rework. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN low-noise transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BC549BTA | Identical electrical specs and TO-92 package; differs only in packing method (ammo vs. tape-and-reel). | No functional difference; selected based on SMT line requirements or manual assembly preference. | Choose BC549BTA for bulk hand-soldering or prototyping; BC549BTAR for automated pick-and-place. |
| BC547B | VCEO = 45 V (vs. 30 V), hFE = 200–450 same class, but higher VCBO = 50 V and no low-noise optimization. | Better suited for higher-voltage switching; less optimal for audio due to unspecified noise figure below 1.4 dB. | Select BC547B when system voltage exceeds 30 V or noise performance is secondary to ruggedness. |
Compared with BC549BTA and BC547B, the BC549BTAR offers the best combination of verified low-noise operation (1.4–4.0 dB), guaranteed Class B hFE, and tape-and-reel packaging for production scalability - making it preferred for audio and precision analog signal chains where both performance and manufacturability matter.
Availability
BC549BTAR is available at Aetrix Electronics and suitable for audio preamplifiers, sensor interface circuits, and discrete switching applications requiring stable component supply, long-lifecycle support, and traceable sourcing.
Supply support for BC549BTAR 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, sensors, and discrete components for automotive, industrial, and consumer applications.
The BC549BTAR belongs to ON Semiconductor's legacy general-purpose transistor product line, designed for cost-sensitive, high-reliability analog signal conditioning and switching in non-critical commercial and industrial equipment.
FAQ
What is the pin configuration of the BC549BTAR?
The BC549BTAR uses a standard TO-92 package with three leads: when viewed from the flat side with leads pointing downward, the leftmost pin is Emitter (1), center is Base (2), and rightmost is Collector (3). This E-B-C arrangement is consistent across the BC546–BC550 family and confirmed in the official ON Semiconductor datasheet Rev. 1.1.1.
Is BC549BTAR suitable for low-noise audio applications?
Yes, the BC549BTAR is explicitly characterized for low-noise operation with a noise figure of 1.4–4.0 dB at VCE = 5 V, IC = 200 μA, RG = 2 kΩ, and 30–15,000 Hz bandwidth. This makes BC549BTAR appropriate for microphone preamplifiers, active filters, and other sensitive analog signal paths where noise performance is critical.
What is the maximum collector current rating for BC549BTAR?
The BC549BTAR has a maximum continuous collector current (IC) rating of 100 mA at TA = 25°C. Derating applies above 25°C ambient; at 100°C case temperature, the usable IC drops to approximately 50 mA. This rating is defined in the Absolute Maximum Ratings table of the BC549BTAR datasheet.
How does BC549BTAR differ from BC549BTA?
The BC549BTAR and BC549BTA share identical electrical specifications, TO-92 package, and marking (BC549B); the only difference is packaging format - BC549BTAR is supplied in tape-and-reel for automated assembly, while BC549BTA is in ammo pack. Both are functionally interchangeable in circuit design.
What is the hFE range for BC549BTAR and how is it binned?
The BC549BTAR is Class B binned with a guaranteed DC current gain (hFE) range of 200–450 at VCE = 5 V and IC = 2 mA. This binning is verified per unit during manufacturing and documented in the Electrical Characteristics table of the BC549BTAR datasheet Rev. 1.1.1.
BC549BTAR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Packaging:
- Tape & Box (TB)
- Product Status:
- Obsolete
- Transistor Type:
- NPN
- Current - Collector (Ic) (Max):
- 100 mA
- Voltage - Collector Emitter Breakdown (Max):
- 30 V
- Vce Saturation (Max) @ Ib, Ic:
- 600mV @ 5mA, 100mA
- Current - Collector Cutoff (Max):
- 15nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 200 @ 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
BC549BTAR FAQ
1.How can I place an order for BC549BTAR through Aetrix?
Please submit a Request for Quotation (RFQ) for BC549BTAR 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 BC549BTAR reliable?
The price and inventory of BC549BTAR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC549BTAR is usually 5 days.
3.What payment methods are accepted for BC549BTAR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC549BTAR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC549BTAR?
BC549BTAR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC549BTAR 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 BC549BTAR?
For technical support, including BC549BTAR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC549BTAR requirements.
6.How does Aetrix verify that BC549BTAR is sourced from the original manufacturer or authorized distributors?
All BC549BTAR 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 BC549BTAR meets industry standards.
7.What is the process for return or replacement of BC549BTAR?
All BC549BTAR units undergo pre-shipment inspection (PSI). If there is an issue with BC549BTAR, 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 BC549BTAR part is unused and in its original packaging.
Return procedure for BC549BTAR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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