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onsemi BC550B_J35Z
- Part No.:
- BC550B_J35Z
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Datasheet:
-
BC550B_J35Z.pdf
- Description:
- TRANS NPN 45V 0.1A TO-92-3
- Quantity:
- Payment:
- Shipping:
Inventory:6,756
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Product details
Overview
BC550B_J35Z 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 at IC = 10 mA. It operates in TO-92 package and is commonly used in audio preamplifier stages, sensor signal conditioning, and discrete logic interface circuits.
For engineers reviewing the BC550B_J35Z datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, terminal mapping, real-world use cases, and validated alternative parts - all aligned to Fairchild/ON Semiconductor's official BC550 family specification Rev. 1.1.1.
Technical Context
This device belongs to the BC546–BC550 NPN transistor family designed for linear amplification and switching in low-to-medium power analog and digital circuits. Its low noise figure (1.4–3.0 dB at 1 kHz) and high fT make it suitable for RF front-end gain stages and precision DC-coupled amplifiers.
The BC550B_J35Z exhibits a VBE(on) of 580–700 mV at IC = 2 mA and VCE = 5 V, with VCE(sat) ≤ 250 mV at IC = 10 mA / IB = 0.5 mA. Its Cob = 3.5–6.0 pF and Cib = 9 pF support stable high-frequency operation up to ~300 MHz under specified bias conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 45 V - Maximum collector-emitter voltage before breakdown; enables use in 24–36 V supply rail amplifier stages. |
| hFE (Class B) | 200–450 - DC current gain range at VCE = 5 V, IC = 2 mA; supports predictable biasing in emitter-follower and common-emitter configurations. |
| fT | 300 MHz - Current gain–bandwidth product at VCE = 5 V, IC = 10 mA; allows stable small-signal amplification up to VHF band. |
| NF | 1.4–3.0 dB - Noise figure at VCE = 5 V, IC = 200 μA, RG = 2 kΩ, f = 1 kHz; qualifies for low-noise microphone preamp and sensor front-end designs. |
| VCBO | 50 V - Collector-base breakdown voltage; defines safe reverse-bias margin during switching transients. |
| VEBO | 5 V - Emitter-base breakdown voltage; constrains base drive circuit design to avoid forward overvoltage damage. |
| IC (max) | 100 mA - Absolute maximum continuous collector current; sets upper limit for load-driving capability in switching applications. |
Pinout & Package
BC550B_J35Z is housed in a JEDEC TO-92 3-lead molded plastic package with straight leads (bulk or ammo packing). Pin 1 is Collector, Pin 2 is Base, Pin 3 is Emitter - confirmed per Figure 7 and ordering table in BC546–BC550 Rev. 1.1.1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Collector) | Main output current path | Carries amplified or switched load current; connects to positive supply or pull-up resistor in common-emitter topology. |
| 2 (Base) | Control input terminal | Accepts bias current to modulate collector current; requires current-limiting resistor when driven from microcontroller GPIO. |
| 3 (Emitter) | Reference and return path | Typically grounded or connected to emitter degeneration resistor; establishes DC operating point and AC signal reference. |
Key Features
| Feature | Design Value |
|---|---|
| Low-noise performance | 1.4–3.0 dB NF at 1 kHz enables high-SNR audio and sensor signal amplification without external noise filtering. |
| High fT bandwidth | 300 MHz gain-bandwidth supports stable small-signal amplification in IF stages and clock buffer applications up to ~100 MHz. |
| TO-92 mechanical compatibility | Standardized 3-lead through-hole footprint ensures drop-in replacement across BC546–BC550 family variants and legacy designs. |
| Class B hFE binning | 200–450 hFE range provides consistent DC bias stability across production lots, reducing need for post-manufacture trimming. |
| Complementary PNP pairing | Designed as NPN counterpart to BC557/BC558 series, enabling matched push-pull output stages and differential amplifiers. |
Applications
| Audio Preamp Stage | Sensor Signal Conditioning |
|---|---|
|
Use Scenario: Amplifying weak signals from electret microphones or piezoelectric sensors in battery-powered voice recorders. IC Role / Device Role / Timing Role: Low-noise NPN amplifier in common-emitter configuration with emitter degeneration. Use Value: 1.4–3.0 dB noise figure preserves signal integrity at sub-mV input levels while maintaining >40 dB voltage gain at 1 kHz. |
Use Scenario: Boosting millivolt-level outputs from thermistors or strain gauges before ADC sampling in industrial monitoring systems. IC Role / Device Role / Timing Role: Discrete DC-coupled gain stage with stable hFE and low VBE drift over temperature. Use Value: 200–450 hFE binning and 580–700 mV VBE(on) enable accurate, repeatable gain calibration without active compensation. |
| Discrete Logic Interface | Switch-Mode Power Control |
|
Use Scenario: Level-shifting and current boosting between 3.3 V MCU GPIO and 12 V relay driver or LED array. IC Role / Device Role / Timing Role: Saturated switch in common-emitter configuration with forced β ≥ 20. Use Value: VCE(sat) ≤ 250 mV at IC = 10 mA / IB = 0.5 mA minimizes conduction loss and self-heating in pulsed control applications. |
Use Scenario: Driving gate resistors of power MOSFETs in low-power DC-DC converters or motor H-bridge half-bridges. IC Role / Device Role / Timing Role: Fast-switching NPN buffer with 300 MHz fT ensuring <100 ns turn-on/turn-off times. Use Value: Cob = 3.5–6.0 pF limits Miller capacitance-induced delay, supporting PWM frequencies up to 500 kHz with clean edge fidelity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN low-noise amplifier and switching applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BC549B | Same VCEO (45 V), identical hFE Class B range (200–450), but slightly higher NF (1.4–4.0 dB vs. 1.4–3.0 dB). | Valid for same audio/sensor roles; marginally less optimal in ultra-low-noise (<2 dB) microphone preamps. | Select BC549B only if BC550B_J35Z is unavailable and NF ≤ 2.5 dB is not required. |
| 2N3904 | Lower VCEO (40 V), lower hFE (100–300), higher VCE(sat) (300 mV), and no guaranteed low-noise binning. | Acceptable for general switching and medium-gain amplification, but unsuitable for <2 dB NF or >40 V supply applications. | Choose 2N3904 only for cost-sensitive, non-critical switching where noise and voltage headroom are secondary. |
Compared with BC549B and 2N3904, BC550B_J35Z delivers the lowest verified noise floor in its class and highest VCEO among standard TO-92 NPNs with hFE ≥ 200 - making it the preferred choice for precision analog front-ends requiring both gain stability and SNR integrity.
Availability
BC550B_J35Z is available at Aetrix Electronics and suitable for audio preamplifier stages, sensor signal conditioning circuits, and discrete logic interface designs requiring stable component supply, long-term obsolescence management, and traceable sourcing.
Supply support for BC550B_J35Z 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 supplier of energy-efficient semiconductor components, specializing in power management, analog, and discrete devices for automotive, industrial, and consumer markets.
The BC550B_J35Z belongs to ON Semiconductor's legacy BC5xx NPN transistor family, originally developed for high-reliability, low-noise linear amplification and robust switching in cost-sensitive through-hole designs.
FAQ
What is the absolute maximum collector-emitter voltage (VCEO) rating for BC550B_J35Z?
The BC550B_J35Z has an absolute maximum VCEO rating of 45 V at TA = 25°C, as specified in the Fairchild/ON Semiconductor BC546–BC550 datasheet Rev. 1.1.1. This rating applies across all BC550 variants (A/B/C) and defines the upper limit for safe DC or peak pulse operation in common-emitter configurations. Exceeding this voltage risks avalanche breakdown and permanent device failure.
Is BC550B_J35Z pin-compatible with other BC5xx transistors like BC547 or BC549?
Yes, BC550B_J35Z uses the standard TO-92 package with identical pinout (1 = Collector, 2 = Base, 3 = Emitter) as BC546, BC547, BC548, BC549, and BC550 variants. This mechanical and electrical pin compatibility allows direct substitution in existing PCB layouts, provided VCEO, hFE, and noise requirements are verified for the target application.
What does the "B" suffix in BC550B_J35Z indicate?
The "B" in BC550B_J35Z denotes the hFE gain bin: 200–450 at VCE = 5 V and IC = 2 mA. This classification distinguishes it from BC550A (110–220) and BC550C (420–800). The J35Z marking is a Fairchild date/batch code and does not affect electrical specifications - all BC550B units meet the same gain range and noise performance.
Can BC550B_J35Z be used in RF amplifier applications?
Yes, BC550B_J35Z is qualified for RF amplifier use up to ~100 MHz due to its 300 MHz fT and low Cob (3.5–6.0 pF). It is commonly deployed in VHF receiver front-ends and IF amplifiers where low noise and moderate gain are prioritized over ultra-high frequency operation. For >200 MHz designs, dedicated RF transistors are recommended.
Does BC550B_J35Z have a specified junction temperature limit?
Yes, BC550B_J35Z has a maximum junction temperature (TJ) of 150°C, as defined in the Absolute Maximum Ratings table of the BC546–BC550 datasheet. This limit must be respected under all operating conditions; thermal design should ensure that power dissipation (≤500 mW) and ambient temperature keep TJ within spec, especially in enclosed or high-temperature environments.
BC550B_J35Z Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- 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
BC550B_J35Z FAQ
1.How can I place an order for BC550B_J35Z through Aetrix?
Please submit a Request for Quotation (RFQ) for BC550B_J35Z 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 BC550B_J35Z reliable?
The price and inventory of BC550B_J35Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC550B_J35Z is usually 5 days.
3.What payment methods are accepted for BC550B_J35Z?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC550B_J35Z transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC550B_J35Z?
BC550B_J35Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC550B_J35Z 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 BC550B_J35Z?
For technical support, including BC550B_J35Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC550B_J35Z requirements.
6.How does Aetrix verify that BC550B_J35Z is sourced from the original manufacturer or authorized distributors?
All BC550B_J35Z 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 BC550B_J35Z meets industry standards.
7.What is the process for return or replacement of BC550B_J35Z?
All BC550B_J35Z units undergo pre-shipment inspection (PSI). If there is an issue with BC550B_J35Z, 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 BC550B_J35Z part is unused and in its original packaging.
Return procedure for BC550B_J35Z:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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