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Nexperia USA Inc. BC857CW-QX
- Part No.:
- BC857CW-QX
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Bipolar Transistors
- Package:
- SC-70, SOT-323
- Datasheet:
-
BC857CW-QX.pdf
- Description:
- TRANS PNP 45V 0.1A SOT-323
- Quantity:
- Payment:
- Shipping:
Inventory:2,468
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Product details
Overview
BC857CW-Q from Nexperia is a PNP general-purpose transistor in SOT323 (SC-70) package, rated for −45 V VCEO, −100 mA IC, and featuring hFE = 420–800 at VCE = −5 V, IC = −2 mA. It serves as a low-power switching or linear amplification device in automotive signal conditioning, sensor interface biasing, and power rail control circuits.
For engineers reviewing the BC857CW-Q datasheet, BC857CW-Q pinout, BC857CW-Q application, or BC857CW-Q equivalent, key selection criteria include its AEC-Q101 qualification, tight hFE spread (420–800), −45 V breakdown rating, SC-70 thermal resistance (625 K/W), and compatibility with reflow/wave soldering per JEDEC J-STD-020/003.
Technical Context
This PNP bipolar junction transistor operates in active, saturation, and cutoff regions with defined DC current gain (hFE) across −55 °C to +150 °C ambient. Its base-emitter and collector-emitter saturation voltages are characterized at IC/IB = 20, supporting predictable switching behavior in low-current logic-level interfaces.
The device's thermal resistance (Rth(j-a) = 625 K/W on FR4 PCB) and maximum junction temperature (Tj = 150 °C) define its safe operating area under pulsed and continuous DC loads up to 200 mW total power dissipation at Tamb ≤ 25 °C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | −45 V - Maximum collector-emitter voltage before breakdown; defines safe operation in 36 V automotive supply rails with margin. |
| IC | −100 mA - Continuous collector current rating; supports load switching up to ~100 mA in compact SMT designs. |
| hFE | 420–800 @ VCE = −5 V, IC = −2 mA - High, tightly binned DC current gain enabling stable biasing with minimal base drive. |
| VCE(sat) | −250 mV max @ IC = −100 mA, IB = −5 mA - Low saturation voltage reduces conduction loss in switching applications. |
| Ptot | 200 mW @ Tamb ≤ 25 °C - Power dissipation limit on standard FR4 PCB; constrains thermal design in enclosed environments. |
| fT | 100 MHz - Transition frequency confirms usable bandwidth for audio-frequency amplification and fast digital switching. |
| AEC-Q101 | Qualified - Meets stress test requirements for automotive discrete semiconductors; supports under-hood and infotainment use. |
Pinout & Package
SOT323 (SC-70) plastic surface-mounted package: 1.3 mm × 1.8 mm footprint, 0.95 mm height, 3-lead configuration with gull-wing terminations compatible with standard reflow profiles.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Base (B) | Current-controlled input node; requires series resistor to limit IB and ensure reliable turn-on/turn-off. |
| 2 | Emitter (E) | Common terminal for PNP topology; connects to higher potential rail (e.g., VCC) in high-side switch configurations. |
| 3 | Collector (C) | Output current path; sinks current from load to ground when biased, enabling low-side switching or amplifier output stage. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing per AEC standard. |
| High hFE bin (C grade) | 420–800 gain range ensures consistent bias point stability across production lots without recalibration. |
| Low VCE(sat) | ≤ −250 mV at full rated current minimizes power loss and self-heating in battery-powered or thermally constrained modules. |
| SOT323 package | Small 1.3 × 1.8 mm outline enables high-density PCB layouts while maintaining manufacturability on standard SMT lines. |
| −55 °C to +150 °C operation | Full specification over extended temperature range supports engine control, ADAS, and under-dash electronics. |
Applications
| Automotive Sensor Biasing | Low-Voltage Logic-Level Switching |
|---|---|
Use Scenario: Providing stable bias current to NTC thermistors or Hall-effect sensors in engine coolant or cabin temperature modules. IC Role / Device Role / Timing Role: PNP current source configured in common-emitter or emitter-follower topology to set sensor operating point. Use Value: Tight hFE binning and −45 V rating ensure accurate, drift-free biasing across automotive temperature extremes. |
Use Scenario: Driving LED indicators or small relays from 3.3 V or 5 V microcontroller GPIO pins in dashboard or body control units. IC Role / Device Role / Timing Role: Low-side switch with base resistor limiting IB to achieve IC ≤ 100 mA. Use Value: −250 mV VCE(sat) and AEC-Q101 qualification guarantee reliable on/off control without thermal runaway. |
| Audio Signal Amplification | Power Rail Sequencing Control |
Use Scenario: Small-signal preamplification stage in infotainment system microphone inputs or speaker protection circuits. IC Role / Device Role / Timing Role: Linear-mode PNP amplifier in common-emitter configuration with emitter degeneration resistor. Use Value: 100 MHz fT and low noise figure (2–10 dB) support clean amplification up to 20 kHz audio band. |
Use Scenario: Enabling/disabling auxiliary power domains (e.g., CAN transceiver VIO) during MCU wake-up/sleep transitions. IC Role / Device Role / Timing Role: High-side enable switch controlling VOUT via emitter-follower configuration. Use Value: −45 V VCEO and −5 V VEBO allow safe operation across 12 V/24 V systems with transient suppression. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PNP general-purpose transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BC857BW-Q | hFE = 220–475 (lower gain, wider spread); same VCEO, IC, package | Less suitable for precision biasing; acceptable where gain tolerance > ±30 % is acceptable | Select when cost sensitivity outweighs need for tight hFE control in non-critical switching. |
| BC847CW-Q | NPN complement; identical hFE (420–800), VCEO = +45 V, same SOT323 package | Requires inverted logic and supply referencing; used in low-side vs. high-side topologies | Choose for NPN-based designs needing matched gain performance and footprint compatibility. |
Compared with BC857BW-Q, BC857CW-Q delivers tighter hFE control for stable biasing; versus BC847CW-Q, it enables high-side switching without level-shifting, simplifying power domain control in mixed-polarity systems.
Availability
BC857CW-Q is available at Aetrix Electronics and suitable for automotive sensor interfaces, low-voltage logic switching, audio signal conditioning, and power rail sequencing requiring stable component supply with AEC-Q101 assurance.
Supply support for BC857CW-Q 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 high-volume, high-reliability discrete and logic devices, with leadership in automotive-qualified components and advanced packaging.
BC857CW-Q belongs to Nexperia's AEC-Q101-qualified BC856/857/858W-Q series of general-purpose PNP transistors, designed specifically for robust, space-constrained automotive signal and power control applications.
FAQ
What is the maximum allowable base current for BC857CW-Q?
The absolute maximum peak base current (IBM) is −200 mA per the datasheet Limiting Values table. For continuous operation, base current must be limited to ensure IC ≤ −100 mA and Ptot ≤ 200 mW, typically using a series resistor calculated from VBE ≈ −650 mV and required IB = IC/hFE(min).
Can BC857CW-Q replace BC857BQ in automotive designs?
No - BC857BQ lacks AEC-Q101 qualification and has different hFE binning (220–475 vs. 420–800). BC857CW-Q meets automotive stress test requirements including HTGB, HTRB, and ESD, making it the only compliant option for safety-critical or under-hood applications.
What is the thermal resistance from junction to ambient for BC857CW-Q on FR4 PCB?
Rth(j-a) is 625 K/W when mounted on a single-sided FR4 PCB with 35 µm copper, tin-plated, and standard SOT323 footprint per Table 7. This value assumes natural convection; forced airflow or thermal vias can reduce effective Rth by up to 30 %.
How does the marking code '3G%' identify BC857CW-Q on the device?
The top-side laser marking '3G%' denotes BC857CW-Q per Table 5, where '3G' is the unique identifier and '%' is a placeholder for the manufacturing site code. This marking is verified under 20× magnification and aligns with Nexperia's traceability protocol for lot-level quality tracking.
BC857CW-QX 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:
- PNP
- 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:
- 420 @ 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
BC857CW-QX FAQ
1.How can I place an order for BC857CW-QX through Aetrix?
Please submit a Request for Quotation (RFQ) for BC857CW-QX 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 BC857CW-QX reliable?
The price and inventory of BC857CW-QX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC857CW-QX is usually 5 days.
3.What payment methods are accepted for BC857CW-QX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC857CW-QX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC857CW-QX?
BC857CW-QX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC857CW-QX 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 BC857CW-QX?
For technical support, including BC857CW-QX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC857CW-QX requirements.
6.How does Aetrix verify that BC857CW-QX is sourced from the original manufacturer or authorized distributors?
All BC857CW-QX 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 BC857CW-QX meets industry standards.
7.What is the process for return or replacement of BC857CW-QX?
All BC857CW-QX units undergo pre-shipment inspection (PSI). If there is an issue with BC857CW-QX, 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 BC857CW-QX part is unused and in its original packaging.
Return procedure for BC857CW-QX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BC857CW-QX Tags
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