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onsemi BCW71
- Part No.:
- BCW71
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
BCW71.pdf
- Description:
- TRANS NPN 45V 0.5A SOT-23-3
- Quantity:
- Payment:
- Shipping:
Inventory:41,440
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Product details
Overview
BCW71 from onsemi is an NPN general-purpose amplifier transistor rated for continuous collector current up to 500 mA, with VCEO = 45 V and fT = 330 MHz, designed for low-to-medium power linear amplification and switching in consumer and industrial signal-path circuits.
For engineers reviewing the BCW71 datasheet, pinout, applications, or equivalent options, key selection criteria include its SOT-23 package footprint, DC current gain (hFE = 110–220), saturation voltage (VCE(sat) ≤ 0.25 V at IC = 10 mA), thermal resistance (RθJA = 357 °C/W), and noise figure (NF = 10 dB at 1 kHz).
Technical Context
The BCW71 is a silicon planar epitaxial NPN transistor fabricated using onsemi's Process 10, optimized for stable DC gain and high-frequency small-signal performance. It supports operation across −55 °C to +150 °C junction temperature with guaranteed breakdown voltages of VCEO = 45 V and VCBO = 50 V.
Its small-signal characteristics include fT = 330 MHz at IC = 10 mA and VCE = 5 V, Cobo = 4.0 pF at VCE = 10 V, and NF = 10 dB under low-current bias (IC = 0.2 mA), making it suitable for RF preamplifier and audio driver stages where gain-linearity and noise control are critical.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 45 V - Maximum safe collector-emitter voltage before breakdown; defines usable supply headroom in amplifier designs. |
| IC (max) | 500 mA - Continuous collector current rating; supports medium-power switching and Class-A/B amplification. |
| hFE | 110–220 - DC current gain at IC = 2 mA, VCE = 5 V; enables predictable biasing in discrete gain stages. |
| fT | 330 MHz - Current-gain bandwidth product; confirms suitability for VHF amplification and fast-switching applications. |
| PD | 350 mW - Total power dissipation at TA = 25 °C; requires thermal derating (2.8 mW/°C) above ambient. |
| NF | 10 dB - Noise figure at IC = 0.2 mA, RS = 2 kΩ, 1 kHz; indicates low-noise capability for sensitive analog front-ends. |
Pinout & Package
BCW71 is housed in a Pb-free, halide-free SOT-23 (TO-236) package (Case 318), measuring 2.90 × 1.30 × 1.00 mm with 1.90 mm lead pitch. Mounting per FR-4 PCB (40 × 40 × 1.5 mm) yields RθJA = 357 °C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Base | Control terminal for forward-biased junction; requires current-limited drive (e.g., via base resistor) to achieve target hFE-based amplification. |
| 2 | Emitter | Common reference node in common-emitter configuration; connected to ground or low-impedance return path for stable biasing. |
| 3 | Collector | Output terminal carrying amplified current; must be decoupled and routed with controlled impedance in RF layouts. |
Key Features
| Feature | Design Value |
|---|---|
| High fT with low Cobo | 330 MHz gain-bandwidth with only 4.0 pF output capacitance - enables stable wideband amplification without excessive neutralization. |
| Low VCE(sat) | ≤ 0.25 V at IC = 10 mA - reduces conduction loss in switching applications and improves efficiency in saturated logic interfaces. |
| Wide operating temperature range | −55 °C to +150 °C junction - supports deployment in automotive under-hood, industrial motor controls, and outdoor electronics. |
| Low-noise performance | NF = 10 dB at 1 kHz - meets requirements for microphone preamps, sensor signal conditioning, and low-level analog receivers. |
Applications
| Audio Pre-amplifier Stage | RF Signal Amplifier |
|---|---|
|
Use Scenario: Boosting weak microphone or line-level signals prior to ADC sampling in portable audio devices. IC Role / Device Role / Timing Role: Discrete NPN transconductance amplifier in common-emitter topology with emitter degeneration. Use Value: Delivers >20 dB voltage gain with <10 dB noise figure and minimal distortion at 1–10 kHz, enabling high-SNR digitization. |
Use Scenario: Low-noise amplification of 30–100 MHz IF signals in AM/FM radio receivers and wireless sensor nodes. IC Role / Device Role / Timing Role: Small-signal RF amplifier with tuned collector load and base bias network. Use Value: Provides 330 MHz fT and 4.0 pF Cobo, supporting stable 20–30 dB gain up to VHF without parasitic oscillation. |
| Switching Regulator Driver | Industrial Sensor Interface |
|
Use Scenario: Driving gate/base of power MOSFETs or IGBTs in DC-DC converter feedback loops and PWM controllers. IC Role / Device Role / Timing Role: Medium-speed switch providing fast turn-on/turn-off (tr/tf < 10 ns at IC = 10 mA). Use Value: Enables clean 100 kHz–1 MHz switching with VCE(sat) ≤ 0.25 V, minimizing driver-stage power loss and thermal rise. |
Use Scenario: Conditioning low-level analog outputs from thermistors, RTDs, or bridge-based pressure sensors in PLC modules. IC Role / Device Role / Timing Role: Precision current-source or differential pair component in instrumentation amplifier front-end. Use Value: Stable hFE (110–220) and low ICBO (<10 nA at 100 °C) ensure accurate, temperature-stable gain over industrial temperature range. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN general-purpose amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BC846B | Higher hFE range (200–450), lower VCEO (65 V), same SOT-23 package and pinout (1=Base, 2=Emitter, 3=Collector). | Better suited for high-gain, low-current biasing (e.g., sensor interface); less ideal for 45 V rail operation due to tighter VCEO margin. | Select BC846B when higher DC gain and lower noise at sub-mA currents are prioritized over maximum voltage headroom. |
| MMBT3904 | Identical pinout and package, but wider hFE spread (100–300), slightly lower fT (300 MHz), and higher VCEO (40 V nominal, 60 V absolute max). | More widely available and cost-optimized; acceptable for general switching but marginal for 45 V continuous operation. | Choose MMBT3904 for cost-sensitive, non-critical linear amplification where 40 V VCEO suffices and 300 MHz fT meets bandwidth needs. |
Compared with BCW71, BC846B offers higher gain consistency at low currents but reduced voltage safety margin, while MMBT3904 provides broader market availability and lower unit cost at the expense of guaranteed 45 V operation and peak fT performance.
Availability
BCW71 is available at Aetrix Electronics and suitable for audio pre-amplifiers, RF signal amplifiers, switching regulator drivers, and industrial sensor interfaces requiring stable component supply, consistent parametric performance, and long-term manufacturability.
Supply support for BCW71 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
onsemi (formerly ON Semiconductor) is a global semiconductor manufacturer specializing in energy-efficient power, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and IoT applications.
The BCW71 belongs to onsemi's legacy general-purpose bipolar transistor family, engineered for reliability and repeatability in discrete amplifier and switching functions across consumer, industrial, and communications equipment.
FAQ
What is the maximum continuous collector current rating for BCW71?
The BCW71 has a maximum continuous collector current (IC) rating of 500 mA at TA = 25 °C. This rating assumes proper PCB thermal management per the datasheet's FR-4 mounting condition. At elevated ambient temperatures, derating applies at 2.8 mW/°C, reducing effective current handling capacity.
Does BCW71 support operation at high ambient temperatures?
Yes, BCW71 is qualified for junction temperatures from −55 °C to +150 °C. Its storage and operating range allows use in harsh environments such as automotive engine compartments or industrial motor drives, provided thermal design maintains TJ ≤ 150 °C under worst-case power dissipation.
What is the pin configuration of BCW71 in the SOT-23 package?
The BCW71 uses Style 6 pinout for SOT-23: Pin 1 is Base, Pin 2 is Emitter, and Pin 3 is Collector. This configuration is confirmed in the onsemi mechanical drawings and marking diagram, and matches standard NPN amplifier orientation for common-emitter circuit implementation.
Is BCW71 suitable for RF amplification up to 100 MHz?
Yes, BCW71 is suitable for RF amplification up to 100 MHz. Its fT of 330 MHz and low output capacitance (Cobo = 4.0 pF) enable stable gain in tuned amplifier stages at VHF frequencies. Measured small-signal characteristics confirm usable gain and phase response through 100 MHz with appropriate matching networks.
How does BCW71 compare to BCW66 in terms of voltage ratings and gain?
BCW71 has VCEO = 45 V and hFE = 110–220, whereas BCW66 specifies VCEO = 32 V and hFE = 100–250. BCW71 offers higher voltage tolerance and tighter gain distribution, making it preferable in 36–45 V supply rails and applications requiring predictable mid-range hFE behavior.
BCW71 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Transistor Type:
- NPN
- Current - Collector (Ic) (Max):
- 500 mA
- Voltage - Collector Emitter Breakdown (Max):
- 45 V
- Vce Saturation (Max) @ Ib, Ic:
- 250mV @ 500µA, 10mA
- Current - Collector Cutoff (Max):
- 100µA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 110 @ 2mA, 5V
- Power - Max:
- 350 mW
- Frequency - Transition:
- 330MHz
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
BCW71 FAQ
1.How can I place an order for BCW71 through Aetrix?
Please submit a Request for Quotation (RFQ) for BCW71 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 BCW71 reliable?
The price and inventory of BCW71 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BCW71 is usually 5 days.
3.What payment methods are accepted for BCW71?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BCW71 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BCW71?
BCW71 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BCW71 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 BCW71?
For technical support, including BCW71 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BCW71 requirements.
6.How does Aetrix verify that BCW71 is sourced from the original manufacturer or authorized distributors?
All BCW71 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 BCW71 meets industry standards.
7.What is the process for return or replacement of BCW71?
All BCW71 units undergo pre-shipment inspection (PSI). If there is an issue with BCW71, 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 BCW71 part is unused and in its original packaging.
Return procedure for BCW71:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BCW71 Tags
-
MMBT3906LT1G
onsemi
-
MMBT3904-7-F
Diodes Incorporated
-
MMBT3904LT1G
onsemi
-
MMBT3906-7-F
Diodes Incorporated
-
MMBT3904-TP
Micro Commercial Co
-
MMBT2222A-7-F
Diodes Incorporated
-
BC846BLT1G
onsemi
-
BC847B,215
Nexperia USA Inc.
-
SMMBT3904LT1G
onsemi
-
MMBT2222A-TP
Micro Commercial Co
-
MMBTA06LT1G
onsemi
-
MMBT2222ALT1G
onsemi
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