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onsemi BC550BBU
- Part No.:
- BC550BBU
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-226-3, TO-92-3 (TO-226AA)
- Datasheet:
-
BC550BBU.pdf
- Description:
- TRANS NPN 45V 0.1A TO-92-3
- Quantity:
- Payment:
- Shipping:
Inventory:2,025
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Product details
Overview
BC550BBU from ON Semiconductor is an NPN epitaxial silicon transistor optimized for low-noise amplifier and general-purpose switching applications, with VCEO = 45 V, hFE = 200–450 (Class B), and fT = 300 MHz. It operates reliably in audio preamplifier stages, sensor signal conditioning circuits, and discrete logic-level interface designs.
For engineers reviewing the BC550BBU datasheet, pinout, applications, or equivalent options, key selection considerations include its low-noise figure (1.4–3.0 dB at 1 kHz), TO-92 package compatibility, VEB0 = 5 V rating, and verified performance at IC = 2 mA and VCE = 5 V.
Technical Context
The BC550BBU implements a planar epitaxial base structure enabling stable hFE across temperature and bias, with specified noise performance validated at IC = 200 μA, VCE = 5 V, RG = 2 kΩ, and f = 1 kHz. Its junction temperature limit of 150°C supports operation in compact, non-ventilated enclosures.
Designed as a direct complement to PNP BC556–BC560 series, it shares identical TO-92 3L mechanical dimensions and thermal resistance (RθJA ≈ 200°C/W), enabling matched-pair use in differential amplifiers and push-pull output stages without layout redesign.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 45 V - Maximum safe collector-emitter voltage before breakdown; enables use in 24 V and 36 V supply rail interfaces. |
| hFE (Class B) | 200–450 - Confirmed DC current gain range at VCE = 5 V, IC = 2 mA; ensures predictable bias stability in fixed-bias amplifier topologies. |
| fT | 300 MHz - Unity-gain bandwidth at VCE = 5 V, IC = 10 mA; supports RF front-end and wideband audio amplification up to ~100 MHz. |
| Noise Figure | 1.4–3.0 dB - Measured at VCE = 5 V, IC = 200 μA, RG = 2 kΩ, f = 1 kHz; qualifies BC550BBU for microphone preamp and instrumentation amplifier inputs. |
| VBE(sat) | 700–900 mV - Base-emitter saturation voltage at IC = 10–100 mA; defines minimum drive voltage required for reliable switching into active region. |
| PC | 500 mW - Maximum continuous collector power dissipation at TA = 25°C; sets thermal derating threshold for PCB copper area and ambient temperature limits. |
Pinout & Package
BC550BBU uses the standard TO-92 3L plastic package (JEDEC TO-92 compliant), with straight leads and bulk packing. Package outline matches Fairchild/ON Semiconductor specification for 3-pin through-hole mounting and manual soldering.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Collector) | Main current output terminal | Connected to load or next stage; must withstand up to 45 V and 100 mA DC; requires adequate trace width for thermal conduction. |
| 2 (Base) | Control input node | Receives bias current to regulate collector current; high-impedance input demands stable voltage source or current-limited driver. |
| 3 (Emitter) | Current return path | Typically grounded or connected to emitter resistor; establishes reference for VBE and sets operating point via IE ≈ IC. |
Key Features
| Feature | Design Value |
|---|---|
| Low-noise amplifier grade | Verified 1.4–3.0 dB noise figure at 1 kHz enables high-SNR analog front-ends without external noise filtering. |
| Matched complementary pair capability | Identical TO-92 footprint and thermal profile with BC556–BC560 series allows symmetrical circuit implementation. |
| High fT / low Cob combination | 300 MHz fT with only 3.5–6.0 pF output capacitance supports stable gain above 50 MHz with minimal neutralization. |
| Controlled hFE binning (Class B) | 200–450 hFE range reduces need for individual circuit trimming in production-grade amplifiers. |
Applications
| Audio Preamp Stage | Sensor Signal Amplification |
|---|---|
Use Scenario: Low-level microphone or piezoelectric sensor signal amplification prior to ADC sampling. IC Role / Device Role / Timing Role: Discrete NPN transconductance amplifier providing 20–40 dB voltage gain with minimal added noise. Use Value: 1.4–3.0 dB noise figure preserves signal integrity in sub-10 mVRMS inputs, avoiding SNR degradation in battery-powered recorders. |
Use Scenario: Amplifying millivolt-level outputs from thermocouples, strain gauges, or photodiodes in industrial monitoring systems. IC Role / Device Role / Timing Role: First-stage DC-coupled amplifier with stable hFE and low VBE drift over temperature. Use Value: Class B hFE binning (200–450) ensures consistent gain across units without per-unit calibration in 1000+ unit batches. |
| Discrete Logic Interface | Linear Voltage Regulator Pass Element |
Use Scenario: Level-shifting and current boosting between 3.3 V microcontroller GPIO and 12 V relay or LED driver loads. IC Role / Device Role / Timing Role: Switch-mode NPN transistor operating in saturation/cutoff with <250 mV VCE(sat) at 10 mA drive. Use Value: Verified VCE(sat) ≤ 250 mV at IC = 10 mA, IB = 0.5 mA ensures <2.5 mW dissipation during on-state, minimizing self-heating. |
Use Scenario: Emitter-follower pass element in adjustable linear regulators delivering up to 100 mA output current. IC Role / Device Role / Timing Role: Series-pass transistor regulating output voltage via feedback-controlled base bias. Use Value: 45 V VCEO rating supports input-to-output differentials up to 40 V, enabling 5 V–36 V adjustable output ranges. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN low-noise amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BC549BTA | Same VCEO = 45 V, identical hFE Class B binning, but lower max fT (150 MHz vs. 300 MHz); same TO-92 package. | Valid for audio and DC-coupled sensor amps below 50 MHz; not recommended for RF-coupled or wideband applications. | Select BC549BTA when cost sensitivity outweighs bandwidth needs and noise figure (1.4–4.0 dB) remains acceptable. |
| 2N5088 | Higher VCEO = 30 V, higher hFE (400–800), lower noise (0.8–2.0 dB), but TO-92 variant with different lead form (bent vs. straight). | Superior noise and gain for ultra-low-level signals; requires PCB footprint adjustment due to bent-lead TO-92 variant. | Choose 2N5088 only if board layout allows bent-lead TO-92 and noise budget demands sub-1.2 dB figure at 1 kHz. |
Compared with BC549BTA, BC550BBU delivers 2× higher fT for wider bandwidth while maintaining identical noise and gain specs; versus 2N5088, BC550BBU offers straight-lead TO-92 compatibility and guaranteed 45 V rating but trades 0.6 dB lower noise floor.
Availability
BC550BBU is available at Aetrix Electronics and suitable for audio preamplifier design, sensor signal conditioning, and discrete logic interface applications requiring stable component supply, consistent hFE binning, and low-noise transistor performance.
Supply support for BC550BBU 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 devices, with headquarters in Phoenix, Arizona.
The BC550BBU belongs to ON Semiconductor's legacy general-purpose bipolar transistor product line, originally developed by Fairchild and maintained for industrial, consumer, and educational applications requiring proven reliability and standardized TO-92 compatibility.
FAQ
What is the maximum collector-emitter voltage rating for BC550BBU?
The BC550BBU has a maximum collector-emitter voltage (VCEO) rating of 45 V at TA = 25°C. This rating is confirmed in the official ON Semiconductor datasheet for the BC546–BC550 family and applies directly to BC550BBU as a member of the BC550 series. Exceeding this voltage risks avalanche breakdown and permanent device damage.
Does BC550BBU have a specified noise figure, and under what conditions is it measured?
Yes, BC550BBU has a specified noise figure of 1.4–3.0 dB, measured at VCE = 5 V, IC = 200 μA, source resistance RG = 2 kΩ, and frequency f = 1 kHz. This value is explicitly documented in the "Electrical Characteristics" table of the BC546–BC550 datasheet and distinguishes BC550BBU as a low-noise variant within the family.
What is the hFE range for BC550BBU, and how is it binned?
BC550BBU is binned to Class B, with a DC current gain (hFE) range of 200–450, tested at VCE = 5 V and IC = 2 mA. This binning is confirmed in the "hFE Classification" table of the BC546–BC550 datasheet and ensures predictable gain behavior across production units without individual calibration.
Is BC550BBU compatible with TO-92 footprint designs intended for BC547 or BC548?
Yes, BC550BBU uses the standard JEDEC TO-92 3L package with straight leads and identical mechanical dimensions to BC547 and BC548. Pinout (1–Collector, 2–Base, 3–Emitter) and thermal characteristics match, enabling drop-in replacement in existing TO-92 layouts without PCB modification.
What is the maximum continuous collector current for BC550BBU?
The maximum continuous collector current (IC) for BC550BBU is 100 mA, as specified in the Absolute Maximum Ratings table of the BC546–BC550 datasheet. This rating assumes operation within the derated power envelope (PC = 500 mW) and junction temperature limit of 150°C.
BC550BBU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA)
- Packaging:
- Bulk
- 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:
- 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
BC550BBU FAQ
1.How can I place an order for BC550BBU through Aetrix?
Please submit a Request for Quotation (RFQ) for BC550BBU 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 BC550BBU reliable?
The price and inventory of BC550BBU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC550BBU is usually 5 days.
3.What payment methods are accepted for BC550BBU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC550BBU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC550BBU?
BC550BBU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC550BBU 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 BC550BBU?
For technical support, including BC550BBU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC550BBU requirements.
6.How does Aetrix verify that BC550BBU is sourced from the original manufacturer or authorized distributors?
All BC550BBU 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 BC550BBU meets industry standards.
7.What is the process for return or replacement of BC550BBU?
All BC550BBU units undergo pre-shipment inspection (PSI). If there is an issue with BC550BBU, 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 BC550BBU part is unused and in its original packaging.
Return procedure for BC550BBU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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