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Nexperia USA Inc. BC849B,235
- Part No.:
- BC849B,235
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Bipolar Transistors
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
BC849B,235.pdf
- Description:
- TRANS NPN 30V 0.1A TO-236AB
- Quantity:
- Payment:
- Shipping:
Inventory:7,948
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Product details
Overview
BC849B,235 from Nexperia is an AEC-Q101-qualified NPN general-purpose transistor in SOT23 package, rated for 30 V VCEO, 100 mA IC, and DC current gain (hFE) of 240 at 10 µA IC. It serves as a low-voltage switching and amplification device in automotive body electronics, sensor interface stages, and power management enable circuits.
For engineers reviewing the BC849B,235 datasheet, BC849B,235 pinout, BC849B,235 application, or BC849B,235 equivalent, this page delivers verified electrical parameters, thermal resistance (500 K/W), saturation voltage (200–600 mV at IC = 100 mA), noise figure (≤4 dB), and AEC-Q101 qualification status - all critical for automotive-grade discrete selection.
Technical Context
The BC849B,235 operates as a silicon planar epitaxial NPN transistor with base-emitter and collector-base junctions optimized for stable DC amplification and fast switching up to 100 MHz fT. Its hFE spans 200–450 across 2–10 mA IC, and VBE remains tightly controlled (660–770 mV) over temperature.
Thermal performance is defined for FR4 PCB mounting: Rth(j-a) = 500 K/W, enabling reliable operation up to Tj = 150 °C. Cut-off currents are specified at 15 nA ICBO (25 °C) and 5 µA (150 °C), supporting low-leakage bias networks in automotive ambient ranges (−65 to +150 °C).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 30 V - Maximum safe collector-emitter voltage under open-base conditions; defines rail compatibility in 24 V automotive systems. |
| IC | 100 mA continuous - Sustained collector current capability; supports LED drivers, relay coils, and logic-level signal buffering. |
| hFE | 240 (typ.) at IC = 10 µA - High DC gain enables low-base-drive designs for battery-sensitive applications. |
| VCE(sat) | 200–600 mV at IC = 100 mA / IB = 5 mA - Low saturation voltage minimizes conduction loss in switching nodes. |
| fT | 100 MHz - Transition frequency confirms suitability for audio-frequency amplification and moderate-speed digital switching. |
| NF | ≤4 dB at 1 kHz - Low noise figure supports precision analog front-end amplification in sensor signal chains. |
| Rth(j-a) | 500 K/W - Thermal resistance on standard FR4 PCB; informs heatsinking requirements for sustained 100 mA operation. |
Pinout & Package
SOT23 plastic surface-mounted package: 3-terminal, 1.9 mm pitch, 2.9 × 1.3 × 1.0 mm body; optimized for automated reflow assembly on FR4 PCBs with tin-plated copper.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Base (B) | Control terminal; requires ~0.5 mA drive for full 100 mA switching; VBE ≈ 660–770 mV at 25 °C. |
| 2 | Emitter (E) | Current return path; tied to ground or low-side reference; forms common-emitter configuration with C and B. |
| 3 | Collector (C) | Output current terminal; connects to load (e.g., LED anode, relay coil); handles up to 30 V and 100 mA continuously. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive underhood and cabin applications per stress test requirements including HTOL, TC, and HTRB. |
| Low VCE(sat) | 200 mV minimum at IC/IB = 20 ensures <10 mW conduction loss in 100 mA switching, reducing thermal load. |
| Stable hFE over temperature | hFE maintains ≥200 from −55 °C to +150 °C (Fig. 2), enabling robust biasing in wide-ambient environments. |
| Low noise figure | ≤4 dB at 1 kHz allows use in microphone preamps and analog sensor amplifiers without added noise degradation. |
| High fT | 100 MHz transition frequency supports clean square-wave switching up to ~10 MHz and audio-band amplification. |
Applications
| Automotive Door Module | Industrial Sensor Interface |
|---|---|
Use Scenario: Driving small solenoids and indicator LEDs in door lock/unlock control circuits. IC Role / Device Role / Timing Role: NPN switch controlling 24 V loads with microcontroller GPIO-level base drive. Use Value: AEC-Q101 qualification ensures reliability across thermal cycling; VCEO = 30 V accommodates load dump transients. |
Use Scenario: Amplifying low-level signals from thermistors and Hall-effect sensors in PLC input modules. IC Role / Device Role / Timing Role: Common-emitter amplifier stage providing 200× DC gain with minimal offset drift. Use Value: hFE stability over −40 to +85 °C ambient eliminates recalibration; NF ≤4 dB preserves SNR. |
| Consumer Power Management | Medical Diagnostic Equipment |
Use Scenario: Enabling/disabling auxiliary rails (e.g., USB-C VBUS detection, display backlight control) in portable devices. IC Role / Device Role / Timing Role: Low-power enable switch with <1 µA leakage (ICBO = 15 nA) preserving standby battery life. Use Value: VBE(sat) < 900 mV at IC = 100 mA reduces gate drive burden on MCU outputs. |
Use Scenario: Isolating and buffering analog signals from ECG electrode front-ends before ADC sampling. IC Role / Device Role / Timing Role: Unity-gain buffer with high input impedance and low output impedance in instrumentation amplifier feedback paths. Use Value: Low VCE(sat) and tight VBE tolerance (±20 mV) minimize DC offset errors in precision analog chains. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN general-purpose transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BC847B,235 | Lower hFE range (110–220), same VCEO/IC ratings and SOT23 package. | Less suitable for low-base-drive designs; higher base current required for same collector current. | Select when cost sensitivity outweighs gain requirement and base drive margin is ample. |
| BC849C,235 | Higher hFE range (420–800), identical voltage/current/thermal specs and footprint. | Better for ultra-low-IB applications (e.g., nanoamp MCU GPIOs), but tighter gain binning increases cost. | Choose when maximizing base-current efficiency is critical and design tolerates wider hFE variation. |
Compared with BC849B,235, BC847B,235 trades gain for cost in non-critical switching, while BC849C,235 extends gain headroom for marginal drive conditions - both retain AEC-Q101 qualification and SOT23 compatibility.
Availability
BC849B,235 is available at Aetrix Electronics and suitable for automotive body control units, industrial sensor signal conditioning, and medical diagnostic equipment requiring stable component supply with AEC-Q101 assurance.
Supply support for BC849B,235 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 semiconductor expert focused on essential efficiency technologies, delivering high-performance, high-reliability discrete and logic devices for automotive, industrial, and consumer markets.
The BC849B,235 belongs to Nexperia's AEC-Q101-qualified general-purpose transistor family, engineered for robustness in automotive ambient conditions and designed to replace legacy BC847/BC849 series with enhanced consistency and qualification rigor.
FAQ
Is BC849B,235 pin-compatible with BC847B,235 and BC849C,235?
Yes - all three share identical SOT23 pinout (1 = Base, 2 = Emitter, 3 = Collector) and mechanical footprint per Fig. 6 and Fig. 7 of the datasheet. No PCB layout change is needed when substituting within the BC847/BC849 series.
What is the maximum allowable junction temperature during continuous operation?
The absolute maximum junction temperature is 150 °C, as defined in Table 5 (Limiting values). Continuous operation at this limit requires derating Ptot to zero above Tamb = 25 °C per Rth(j-a) = 500 K/W; practical design limits Tj to ≤125 °C for long-term reliability.
Does BC849B,235 support wave soldering?
Yes - the device is qualified for wave soldering using the footprint in Fig. 8 (sot023_fw), with recommended solder land dimensions of 1.4 mm × 1.2 mm (2×) and transport direction aligned with pin 1–3 axis to ensure uniform wetting and avoid tombstoning.
How does hFE vary with collector current and temperature?
hFE peaks near 2–10 mA IC (200–450 typ.), then declines above 20 mA; at −55 °C it drops ~25% vs. 25 °C, and at +150 °C it falls ~40% - data confirmed in Fig. 2 and Table 7, enabling accurate bias point selection across operating ranges.
BC849B,235 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- 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):
- 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:
- 250 mW
- Frequency - Transition:
- 100MHz
- Operating Temperature:
- 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TO-236AB
BC849B,235 FAQ
1.How can I place an order for BC849B,235 through Aetrix?
Please submit a Request for Quotation (RFQ) for BC849B,235 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 BC849B,235 reliable?
The price and inventory of BC849B,235 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC849B,235 is usually 5 days.
3.What payment methods are accepted for BC849B,235?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC849B,235 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC849B,235?
BC849B,235 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC849B,235 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 BC849B,235?
For technical support, including BC849B,235 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC849B,235 requirements.
6.How does Aetrix verify that BC849B,235 is sourced from the original manufacturer or authorized distributors?
All BC849B,235 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 BC849B,235 meets industry standards.
7.What is the process for return or replacement of BC849B,235?
All BC849B,235 units undergo pre-shipment inspection (PSI). If there is an issue with BC849B,235, 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 BC849B,235 part is unused and in its original packaging.
Return procedure for BC849B,235:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BC849B,235 Tags
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