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Nexperia USA Inc. BC857AW-QF
- Part No.:
- BC857AW-QF
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Bipolar Transistors
- Package:
- SC-70, SOT-323
- Datasheet:
-
BC857AW-QF.pdf
- Description:
- TRANS PNP 45V 0.1A SOT-323
- Quantity:
- Payment:
- Shipping:
Inventory:9,297
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Product details
Overview
BC857AW-Q from Nexperia is a PNP general-purpose bipolar junction transistor (BJT) in SOT323 (SC-70) package, rated for −45 V VCEO, −100 mA IC, and DC current gain (hFE) of 125–250 at VCE = −5 V, IC = −2 mA. It serves as a low-power switching or linear amplification device in automotive signal conditioning, sensor interface, and LED driver stages.
For engineers reviewing the BC857AW-Q datasheet, BC857AW-Q pinout, BC857AW-Q application, or BC857AW-Q equivalent, this page delivers verified electrical parameters, AEC-Q101 qualification status, thermal resistance (625 K/W), saturation voltage (−250 mV typ. at IC = −100 mA), and automotive-grade reliability context - all critical for board-level validation and BOM selection.
Technical Context
This PNP BJT operates in active, saturation, and cutoff regions with defined absolute maximum ratings: −45 V collector-emitter voltage (open base), −50 V collector-base voltage, and −5 V emitter-base voltage. Its hFE range (125–250) supports predictable biasing in fixed-gain amplifier configurations and digital logic-level switching.
Thermal performance is characterized by Rth(j-a) = 625 K/W on FR4 PCB (single-sided, 35 µm Cu), and it exhibits VCE(sat) ≤ −250 mV at IC = −100 mA / IB = −5 mA, enabling efficient low-voltage switching in space-constrained automotive modules.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | −45 V - Maximum safe collector-emitter voltage with open base; defines upper rail limit in PNP switch applications. |
| IC | −100 mA - Continuous DC collector current rating; sets load-driving capability in signal-level switching. |
| hFE | 125–250 @ VCE = −5 V, IC = −2 mA - Predictable DC current gain for stable bias design in amplifiers and saturated switches. |
| VCE(sat) | ≤ −250 mV @ IC = −100 mA, IB = −5 mA - Low saturation voltage minimizes power loss and heating in high-duty-cycle switching. |
| Rth(j-a) | 625 K/W - Junction-to-ambient thermal resistance on standard FR4 PCB; informs derating requirements above 25 °C ambient. |
| AEC-Q101 | Qualified - Meets stress test requirements for automotive discrete semiconductors; suitable for under-hood and body-control modules. |
Pinout & Package
SOT323 (SC-70) plastic surface-mounted package: 1.3 mm × 1.8 mm footprint, 0.95 mm height, 3-terminal leadless construction optimized for high-density PCB layouts and reflow assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Base (B) | Control terminal; requires current-limited drive to achieve specified hFE-based collector current scaling. |
| 2 | Emitter (E) | Current source node in PNP configuration; connected to higher potential rail in common-emitter switch topologies. |
| 3 | Collector (C) | Output current sink node; connects to load and lower-potential rail in standard switching arrangements. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive use per Stress Test Qualification for Discrete Semiconductors - enables deployment in engine control, lighting, and ADAS subsystems without additional qualification effort. |
| Low VCE(sat) | −250 mV typical at full rated current ensures <12.5 mW conduction loss in 100 mA switching, reducing thermal load in sealed enclosures. |
| Small SOT323 package | 1.3 × 1.8 mm footprint saves >60% board area vs. SOT23, supporting miniaturized ECUs and sensor nodes with strict size constraints. |
| Wide hFE range | 125–250 allows robust bias network design across process variation while maintaining guaranteed turn-on margin in worst-case temperature conditions. |
Applications
| Automotive Interior Lighting Control | Engine Coolant Temperature Sensor Interface |
|---|---|
|
Use Scenario: Driving 20 mA white LEDs in dashboard backlighting circuits with 12 V supply and PWM dimming. IC Role / Device Role / Timing Role: PNP switch controlling LED cathode current path; operates in saturation during ON phase and cutoff during OFF phase. Use Value: −250 mV VCE(sat) limits power dissipation to <5 mW per channel, eliminating need for heatsinking in multi-LED clusters. |
Use Scenario: Level-shifting and buffering analog output from NTC-based coolant sensor to MCU ADC input. IC Role / Device Role / Timing Role: Emitter-follower amplifier providing low-impedance drive to 10 kΩ ADC input while isolating sensor from loading effects. Use Value: hFE ≥125 ensures stable current sourcing into varying ADC sampling capacitance across −40 °C to +125 °C ambient. |
| Body Control Module Power Sequencing | Occupancy Detection Circuit Amplifier |
|
Use Scenario: Enabling 5 V auxiliary rails only after main 12 V system stabilizes, using microcontroller GPIO to drive BC857AW-Q base. IC Role / Device Role / Timing Role: High-side switch controlling PMOS gate pull-down; acts as level translator between 3.3 V logic and 12 V domain. Use Value: −45 V VCEO provides 15 V margin above nominal 12 V automotive rail, accommodating load-dump transients up to ISO 7637-2 Pulse 1. |
Use Scenario: Amplifying weak capacitive-sensing signals (<100 µV) from seat occupancy electrodes before ADC digitization. IC Role / Device Role / Timing Role: Common-emitter preamplifier stage with resistive bias network; sets first-stage gain and noise floor. Use Value: NF = 2 dB @ 1 kHz enables detection of sub-100 nA displacement currents without requiring costly op-amp solutions. |
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 (higher gain band); same VCEO, IC, package | Better suited for low-base-drive amplifier designs where tighter hFE tolerance reduces bias resistor sensitivity | Select when designing for minimal base current consumption or improved gain stability across temperature |
| BC847AW-Q | NPN complement; identical hFE (125–250), VCEO = +45 V, same SOT323 package | Used in low-side switching or NPN amplifier topologies where polarity reversal is acceptable | Choose for complementary pair designs or when circuit topology mandates NPN configuration |
Compared with BC857AW-Q, BC857BW-Q offers higher and narrower hFE for reduced base drive variability, while BC847AW-Q provides matched gain in NPN form for push-pull or differential stages - both retain AEC-Q101 qualification and SOT323 compatibility.
Availability
BC857AW-Q is available at Aetrix Electronics and suitable for automotive interior lighting control, engine sensor interface, body control module sequencing, and occupancy detection circuits requiring stable component supply, AEC-Q101 compliance, and SOT323 footprint consistency.
Supply support for BC857AW-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 specializing in high-performance, reliable discrete, logic, and MOSFET devices, with leadership in automotive-qualified components and energy-efficient packaging.
The BC857AW-Q belongs to Nexperia's AEC-Q101-qualified general-purpose transistor family, engineered for robust operation in automotive signal switching and amplification applications where space, thermal, and reliability constraints are critical.
FAQ
What is the maximum operating temperature for BC857AW-Q?
The BC857AW-Q has a maximum junction temperature (Tj) of 150 °C and an ambient operating range of −65 °C to +150 °C. Its thermal resistance Rth(j-a) is 625 K/W on standard FR4 PCB, so at 100 mA continuous current and 25 °C ambient, junction temperature rise is ~15.6 °C - well within safe limits. Derating is required above 25 °C ambient per the datasheet's thermal curves.
Is BC857AW-Q pin-compatible with BC847AW-Q?
Yes - BC857AW-Q (PNP) and BC847AW-Q (NPN) share identical SOT323 (SC-70) package dimensions and pinout: Pin 1 = Base, Pin 2 = Emitter, Pin 3 = Collector. This allows direct layout reuse in complementary designs, though polarity reversal must be accounted for in schematic and biasing networks.
Does BC857AW-Q support wave soldering?
Yes - Nexperia specifies wave soldering footprints for SOT323 in its datasheet (Figure 16), including recommended solder land dimensions (3.65 mm × 2.1 mm), solder resist openings, and preferred transport direction. The device is qualified for both reflow and wave processes per J-STD-020 and J-STD-006 standards.
What marking code identifies BC857AW-Q on the package?
The top-side marking for BC857AW-Q is "3E%", where "%" is a placeholder for the manufacturing site code. This 2-character alphanumeric code (plus site identifier) is laser-marked on the device body and corresponds exclusively to the BC857AW-Q variant per Table 5 of the Nexperia datasheet Rev. 2.
BC857AW-QF 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:
- 125 @ 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
BC857AW-QF FAQ
1.How can I place an order for BC857AW-QF through Aetrix?
Please submit a Request for Quotation (RFQ) for BC857AW-QF 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 BC857AW-QF reliable?
The price and inventory of BC857AW-QF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC857AW-QF is usually 5 days.
3.What payment methods are accepted for BC857AW-QF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC857AW-QF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC857AW-QF?
BC857AW-QF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC857AW-QF 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 BC857AW-QF?
For technical support, including BC857AW-QF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC857AW-QF requirements.
6.How does Aetrix verify that BC857AW-QF is sourced from the original manufacturer or authorized distributors?
All BC857AW-QF 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 BC857AW-QF meets industry standards.
7.What is the process for return or replacement of BC857AW-QF?
All BC857AW-QF units undergo pre-shipment inspection (PSI). If there is an issue with BC857AW-QF, 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 BC857AW-QF part is unused and in its original packaging.
Return procedure for BC857AW-QF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BC857AW-QF Tags
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