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Nexperia USA Inc. BC850BW,135
- Part No.:
- BC850BW,135
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Bipolar Transistors
- Package:
- SC-70, SOT-323
- Datasheet:
-
BC850BW,135.pdf
- Description:
- TRANS NPN 45V 0.1A SOT-323
- Quantity:
- Payment:
- Shipping:
Inventory:9,780
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Product details
Overview
BC850BW,135 from Nexperia is an NPN general-purpose bipolar junction transistor in SOT323 package, rated for 45 V VCEO, 100 mA IC, and featuring hFE of 200–450 at 2 mA/5 V; used in low-noise audio preamplifier stages of hi-fi amplifiers and tape recorders.
For engineers reviewing the BC850BW,135 datasheet, BC850BW,135 pinout, BC850BW,135 application, or BC850BW,135 equivalent, this part serves as a low-voltage, low-current discrete amplifier with verified noise performance (4 dB @ 1 kHz), tight DC gain spread, and SOT323 footprint compatibility for space-constrained analog signal paths.
Technical Context
This NPN transistor operates in linear active mode for small-signal amplification, with base-emitter turn-on voltage of 580–700 mV and collector-emitter saturation voltage ≤250 mV at 10 mA/0.5 mA drive. Its fT of 100 MHz supports audio-band fidelity without high-frequency roll-off.
Thermal resistance Rth j-a is 625 K/W on FR4 PCB, limiting continuous power dissipation to 200 mW at Tamb ≤25 °C; leakage currents (ICBO ≤15 nA, IEBO ≤100 nA) ensure stable biasing in precision analog front-ends.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 45 V - maximum safe collector-emitter voltage before breakdown in common-emitter configuration |
| IC (DC) | 100 mA - continuous collector current limit defining usable signal swing and bias headroom |
| hFE | 200–450 - DC current gain range at 2 mA/5 V, enabling predictable bias network design |
| VCE(sat) | ≤250 mV @ 10 mA/0.5 mA - low saturation voltage preserves voltage headroom in switching or Class-A amplifier use |
| fT | 100 MHz - transition frequency confirming adequate bandwidth for full audio spectrum (20 Hz–20 kHz) |
| Fnoise | 4 dB @ 1 kHz - measured noise figure supporting low-noise preamp stage requirements |
| Cc | 3 pF - collector junction capacitance minimizing Miller effect in high-gain configurations |
Pinout & Package
SOT323 plastic surface-mount package (2.2 mm × 1.35 mm × 0.95 mm), 3-lead, JEDEC SC-70 compliant, optimized for automated placement and thermal relief on FR4 boards.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Base | Current-controlled input node; requires series resistor to limit IB and stabilize Q-point |
| 2 | Emitter | Common reference terminal; connects to ground or emitter degeneration resistor in CE amplifiers |
| 3 | Collector | Output node carrying amplified current; ties to load resistor or next-stage input via coupling capacitor |
Key Features
| Feature | Design Value |
|---|---|
| Low-noise operation | 4 dB noise figure at 1 kHz enables use in microphone preamps and phono stages without added noise floor |
| Tight hFE binning | 200–450 range reduces need for individual bias trimming in production audio equipment |
| Low VCE(sat) | ≤250 mV at 10 mA ensures >95% supply utilization in battery-powered portable audio devices |
| SOT323 footprint | Standardized 0.65 mm pitch allows drop-in replacement with BC849BW, BC859W (PNP complement), and other SC-70 transistors |
Applications
| Audio Preamp Stage | Tape Recorder Input Amplifier |
|---|---|
Use Scenario: First amplification stage for dynamic microphone signals with <10 mV RMS input. IC Role / Device Role / Timing Role: NPN small-signal amplifier in common-emitter configuration with emitter degeneration. Use Value: 4 dB noise figure and 200–450 hFE enable clean gain of 100× without audible hiss or distortion. | Use Scenario: Input buffer and equalization driver in analog cassette playback circuitry. IC Role / Device Role / Timing Role: Linear amplifier with fixed bias network for flat frequency response across 50 Hz–15 kHz. Use Value: 100 MHz fT and 3 pF Cc prevent phase shift and high-frequency attenuation in RIAA playback EQ networks. |
| Hi-Fi Tone Control Buffer | Portable Audio Line Driver |
Use Scenario: Isolation amplifier between passive tone stack and power amplifier input. IC Role / Device Role / Timing Role: Unity-gain emitter follower providing low-output impedance and high input impedance. Use Value: ≤250 mV VCE(sat) and 100 mA IC rating support rail-to-rail signal swing into 10 kΩ loads. | Use Scenario: Output driver for headphone amplifier IC feeding 32 Ω loads in battery-powered players. IC Role / Device Role / Timing Role: Current-boosting stage operating in Class-A with emitter-follower topology. Use Value: 200 mW Ptot and 625 K/W Rth j-a allow sustained 50 mA output without thermal shutdown on compact PCBs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN small-signal amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BC849BW,135 | VCEO = 30 V (vs. 45 V); same hFE range and SOT323 package | Not suitable for 36 V rail designs; acceptable in 12–24 V audio systems with margin | Select when lower voltage rating suffices and cost optimization is prioritized |
| MMBT3904LT1G | hFE = 100–300 (wider spread); VCEO = 40 V; 225 mW Ptot | Higher noise figure (5 dB); less consistent gain matching across batches | Choose for non-critical digital switching where gain tolerance is relaxed |
Compared with BC849BW,135 and MMBT3904LT1G, BC850BW,135 delivers higher voltage margin, tighter hFE, and lower noise-making it optimal for production hi-fi and professional audio signal chains where consistency and SNR are design-critical.
Availability
BC850BW,135 is available at Aetrix Electronics and suitable for audio preamplifiers, tape recorder signal chains, and hi-fi tone control buffers requiring stable component supply, long-term obsolescence management, and RoHS-compliant sourcing.
Supply support for BC850BW,135 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
Nexperia is a global leader in high-volume discrete, logic, and PowerMOS semiconductors, spun off from NXP in 2017 and focused on automotive, industrial, computing, and consumer markets.
BC850BW,135 belongs to Nexperia's general-purpose bipolar transistor product line, engineered specifically for reliable, low-noise analog signal conditioning in cost-sensitive audio and consumer electronics.
FAQ
What is the maximum operating temperature for BC850BW,135?
The BC850BW,135 has a maximum junction temperature (Tj) of 150 °C and an operating ambient temperature range of −65 °C to +150 °C. Derating is required above 25 °C ambient per the 625 K/W thermal resistance; at 70 °C ambient, maximum continuous power drops to ~120 mW.
Is BC850BW,135 pin-compatible with BC849BW,135?
Yes-both use identical SOT323 package and pinout (Pin 1 = Base, Pin 2 = Emitter, Pin 3 = Collector). The only functional difference is VCEO rating: 45 V for BC850BW versus 30 V for BC849BW. No layout change is needed for substitution where voltage margin permits.
Does BC850BW,135 support surface-mount reflow soldering?
Yes-BC850BW,135 is qualified for standard lead-free reflow profiles (J-STD-020), including peak temperatures up to 260 °C for ≤30 seconds. Its plastic SOT323 body meets moisture sensitivity level (MSL) 1, allowing unlimited floor life at ≤30 °C/60% RH.
What is the typical noise performance in audio applications?
BC850BW,135 achieves a noise figure of 4 dB at 1 kHz with 200 μA collector current, 5 V VCE, and 2 kΩ source resistance. This is measured across 200 Hz–20 kHz bandwidth and validated in tape recorder input stages where low-noise gain below 100 μV input is critical.
BC850BW,135 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Series:
- -
- Package/Case:
- SC-70, SOT-323
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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:
- 200 mW
- Frequency - Transition:
- 100MHz
- Operating Temperature:
- 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-323
BC850BW,135 FAQ
1.How can I place an order for BC850BW,135 through Aetrix?
Please submit a Request for Quotation (RFQ) for BC850BW,135 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 BC850BW,135 reliable?
The price and inventory of BC850BW,135 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC850BW,135 is usually 5 days.
3.What payment methods are accepted for BC850BW,135?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC850BW,135 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC850BW,135?
BC850BW,135 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC850BW,135 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 BC850BW,135?
For technical support, including BC850BW,135 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC850BW,135 requirements.
6.How does Aetrix verify that BC850BW,135 is sourced from the original manufacturer or authorized distributors?
All BC850BW,135 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 BC850BW,135 meets industry standards.
7.What is the process for return or replacement of BC850BW,135?
All BC850BW,135 units undergo pre-shipment inspection (PSI). If there is an issue with BC850BW,135, 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 BC850BW,135 part is unused and in its original packaging.
Return procedure for BC850BW,135:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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