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Nexperia USA Inc. BC857W-QX
- Part No.:
- BC857W-QX
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Bipolar Transistors
- Package:
- SC-70, SOT-323
- Datasheet:
-
BC857W-QX.pdf
- Description:
- TRANS PNP 45V 0.1A SOT-323
- Quantity:
- Payment:
- Shipping:
Inventory:9,740
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Product details
Overview
BC857W-Q from Nexperia is a PNP general-purpose bipolar junction transistor in SOT323 (SC-70) package, rated for −45 V VCEO, −100 mA IC, and DC current gain (hFE) of 125–800 at VCE = −5 V, IC = −2 mA. It serves as a low-power switching or linear amplification device in automotive signal conditioning, sensor interface, and logic-level translation circuits.
For engineers reviewing the BC857W-Q datasheet, BC857W-Q pinout, BC857W-Q application, or BC857W-Q equivalent, this page delivers verified electrical parameters, AEC-Q101 qualification status, thermal resistance (625 K/W), saturation voltage (−250 to −600 mV at IC = −100 mA), and exact SC-70 pin mapping - all critical for automotive-grade PCB layout and reliability validation.
Technical Context
The BC857W-Q operates as a silicon PNP BJT with base-emitter and collector-base junctions optimized for stable DC gain across −55 °C to +150 °C ambient. Its V(BR)CEO = −45 V and V(BR)CBO = −50 V define safe blocking capability in low-voltage automotive rails.
Thermal performance is characterized by Rth(j-a) = 625 K/W on FR4 PCB (single-sided, 35 µm Cu), and transient thermal impedance curves confirm suitability for pulsed switching up to 200 mA peak. Noise figure is 2–10 dB at 1 kHz, supporting low-noise analog front-end use.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | −45 V: Maximum collector-emitter voltage before breakdown; enables use in 36 V automotive systems with margin. |
| IC | −100 mA continuous: Supports load switching for LEDs, relays, and small solenoids in body electronics. |
| hFE | 125–800 at VCE = −5 V, IC = −2 mA: Wide gain spread allows flexible bias design without external feedback. |
| VCE(sat) | −250 to −600 mV at IC = −100 mA, IB = −5 mA: Low saturation voltage minimizes power loss in high-duty-cycle switches. |
| Ptot | 200 mW at Tamb ≤ 25 °C: Limits thermal derating above 25 °C; requires PCB copper area planning for sustained operation. |
| fT | 100 MHz: Enables RF pre-amplification and fast digital switching up to ~10 MHz edge rates. |
| Rth(j-a) | 625 K/W: Thermal resistance defines junction temperature rise; 100 mA conduction raises Tj by ~62.5 °C over ambient. |
Pinout & Package
SOT323 (SC-70) plastic surface-mounted package: 1.35 mm × 1.75 mm footprint, 0.95 mm height, 3-lead configuration with gull-wing terminations for reflow soldering.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Base (B) | Control terminal; requires current-limited drive (max IB = −200 mA peak) to avoid thermal runaway. |
| 2 | Emitter (E) | Current source node; connected to higher potential rail in PNP switch configurations. |
| 3 | Collector (C) | Current sink node; ties to load and ground; must withstand −45 V reverse bias when off. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive applications including engine control modules and body controllers per stress test requirements. |
| Low VCE(sat) | −250 mV typical at full rated current ensures <10 mW conduction loss in 100 mA loads. |
| Wide hFE range | 125–800 supports production binning and eliminates need for gain-matching in cost-sensitive designs. |
| SC-70 footprint | 0.65 mm pitch and 1.35 mm width enable high-density routing in space-constrained ADAS and infotainment PCBs. |
| 150 °C Tj(max) | Enables operation in under-hood environments without forced cooling or derating below −40 °C to +125 °C ambient. |
Applications
| Automotive Door Module Switching | Industrial Sensor Signal Amplification |
|---|---|
|
Use Scenario: Driving window lift motor control logic and door lock actuators in 12 V/24 V vehicle architectures. IC Role / Device Role / Timing Role: PNP switch enabling high-side load control with microcontroller GPIO-level base drive. Use Value: −45 V VCEO accommodates load dump transients; −250 mV VCE(sat) limits self-heating during 100% duty cycle operation. |
Use Scenario: Amplifying low-level output from NTC thermistors and Hall-effect sensors in PLC I/O modules. IC Role / Device Role / Timing Role: Linear amplifier stage providing 20–40 dB gain with minimal distortion at DC–10 kHz. Use Value: 2–10 dB noise figure and stable hFE across −55 °C to +125 °C ensure repeatable analog accuracy in harsh environments. |
| Consumer Appliance Power Sequencing | Medical Diagnostic Equipment Bias Control |
|
Use Scenario: Enabling sequential power-up of display backlight, fan, and MCU subsystems in smart home appliances. IC Role / Device Role / Timing Role: Discrete PNP switch implementing hardware-based power sequencing with fixed time constants. Use Value: 200 mW Ptot and 625 K/W thermal resistance allow reliable operation on standard FR4 without heatsinking. |
Use Scenario: Providing precision bias current to photodiode transimpedance amplifiers in portable ultrasound units. IC Role / Device Role / Timing Role: Current source configured with emitter degeneration resistor for stable IC regulation. Use Value: Tight VBE matching (±50 mV) and low leakage (ICBO < −4 µA at 150 °C) maintain calibration integrity over lifetime. |
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 |
|---|---|---|---|
| BC847W-Q | NPN complement; identical SOT323 package, same VCEO/IC ratings but opposite polarity. | Requires inverted control logic and reversed supply topology; unsuitable for high-side switching without level shift. | Select only when circuit architecture mandates NPN configuration or complementary pair usage. |
| MMBT3906LT1G | −40 V VCEO, −200 mA IC, hFE = 100–300; slightly lower voltage rating but higher current capability. | Better suited for higher-current loads (e.g., >100 mA relay coils); less margin for 36 V automotive transients. | Prefer when peak load current exceeds 100 mA and −45 V blocking is not required. |
Compared with BC847W-Q and MMBT3906LT1G, the BC857W-Q offers superior voltage margin for 24 V automotive systems, tighter hFE consistency than MMBT3906LT1G, and direct drop-in compatibility in existing SOT323 PNP layouts without redesign.
Availability
BC857W-Q is available at Aetrix Electronics and suitable for automotive body control modules, industrial sensor interfaces, and consumer appliance power sequencing requiring stable component supply, AEC-Q101 compliance, and SOT323 footprint consistency.
Supply support for BC857W-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 essential efficiency-enhancing components, delivering high-volume, high-reliability discrete and logic devices for automotive, industrial, and consumer markets.
The BC857W-Q belongs to Nexperia's AEC-Q101-qualified general-purpose transistor product line, engineered specifically for robust, cost-effective switching and amplification in automotive electronics where thermal stability and long-term reliability are mandatory.
FAQ
Is BC857W-Q suitable for high-frequency switching above 10 MHz?
Yes - its 100 MHz transition frequency (fT) supports clean switching up to ~10 MHz with controlled rise/fall times. However, parasitic capacitances (Cc = 3 pF, Ce = 12 pF) require careful gate/base drive impedance matching to avoid ringing in hard-switched topologies.
What is the maximum allowable base current for continuous operation?
The absolute maximum peak base current is −200 mA, but continuous operation should be limited to ≤−5 mA to prevent thermal overstress. At IC = −100 mA, a typical IB of −5 mA yields IC/IB = 20, aligning with the specified VCE(sat) test condition and ensuring stable gain behavior.
Does BC857W-Q support wave soldering?
Yes - Nexperia provides dedicated wave soldering footprints (Fig. 16) with 3.65 mm × 2.1 mm land pattern and 1.425 mm × 4.6 mm solder resist openings. Recommended preheat ≤100 °C and contact time ≤5 seconds to avoid package warpage or internal bond damage.
How does BC857W-Q differ from BC857BW-Q in practical design?
The BC857BW-Q has a narrower hFE range (220–475 vs. 125–800), tighter VBE distribution, and improved consistency in saturation voltage. Use BC857W-Q for cost-sensitive, non-critical gain applications; choose BC857BW-Q when predictable turn-on threshold and reduced binning variation are required.
BC857W-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:
- 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
BC857W-QX FAQ
1.How can I place an order for BC857W-QX through Aetrix?
Please submit a Request for Quotation (RFQ) for BC857W-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 BC857W-QX reliable?
The price and inventory of BC857W-QX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC857W-QX is usually 5 days.
3.What payment methods are accepted for BC857W-QX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC857W-QX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC857W-QX?
BC857W-QX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC857W-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 BC857W-QX?
For technical support, including BC857W-QX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC857W-QX requirements.
6.How does Aetrix verify that BC857W-QX is sourced from the original manufacturer or authorized distributors?
All BC857W-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 BC857W-QX meets industry standards.
7.What is the process for return or replacement of BC857W-QX?
All BC857W-QX units undergo pre-shipment inspection (PSI). If there is an issue with BC857W-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 BC857W-QX part is unused and in its original packaging.
Return procedure for BC857W-QX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BC857W-QX Tags
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MMBT3906LT1G
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MMBT3906-7-F
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MMBTA06LT1G
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