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Home > Products > Discrete Semiconductor Products > Transistors > Bipolar (BJT) > Single Bipolar Transistors

Nexperia USA Inc. BC857BQB-QZ

Name: BC857BQB-QZ
Brand: Nexperia USA Inc.
SKU: BC857BQB-QZ
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BC857BQB-QZ

Manufacturer:: Nexperia USA Inc.

Category:: Single Bipolar Transistors

Package:: 3-XDFN Exposed Pad

Datasheet:: BC857BQB-QZ.pdf

Description:: TRANS PNP 45V 0.1A DFN1110D-3

Quantity:: RFQ Add To RFQ list

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Product details

Overview

BC857BQB-Q from Nexperia is a PNP general-purpose transistor in a DFN1110D-3 (SOT8015) leadless package, rated for −45 V V_CEO, −100 mA I_C, and DC current gain (h_FE) of 220–475 at V_CE = −5 V and I_C = −2 mA. It delivers low V_CEsat (≤ −650 mV at I_C = −100 mA, I_B = −5 mA) and supports automotive-grade reliability per AEC-Q101.

For engineers reviewing the BC857BQB-Q datasheet, BC857BQB-Q pinout, BC857BQB-Q application, or BC857BQB-Q equivalent, this device serves as a space-constrained, high-reliability switching and amplification solution in automotive body electronics, sensor interface stages, and low-power logic-level translation circuits where side-wettable flanks enable AOI-compatible solder joint inspection.

Technical Context

This PNP bipolar junction transistor operates with open-base collector-emitter breakdown voltage of −45 V and emitter-base breakdown voltage of −6 V, supporting robust operation under reverse-biased conditions typical in level-shifting and load-switching topologies. Its thermal resistance R_th(j-a) is 298 K/W on 70 µm FR4 PCB, enabling stable performance up to 150 °C junction temperature.

The device exhibits f_T = 100 MHz at V_CE = −5 V and I_C = −10 mA, confirming suitability for medium-speed switching (e.g., PWM dimming control), while its low C_c = 2 pF and C_e = 10 pF minimize capacitive loading in high-impedance bias networks.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	−45 V - Maximum safe collector-emitter voltage with base open; defines upper rail tolerance in high-side switch configurations.
I_C	−100 mA - Continuous DC collector current rating; supports signal-level loads like LED drivers or small relays.
h_FE	220–475 - DC current gain range at −5 V V_CE, −2 mA I_C; enables predictable base drive sizing for saturation in switching applications.
V_CEsat	≤ −650 mV - Collector-emitter saturation voltage at −100 mA I_C, −5 mA I_B; ensures <100 mW power loss in saturated on-state.
P_tot	420 mW - Max power dissipation on 70 µm FR4 PCB; sets thermal derating boundary for ambient temperatures up to 125 °C.
T_j	150 °C - Maximum junction temperature; validated for automotive under-hood environments per AEC-Q101 stress testing.

Pinout & Package

BC857BQB-Q uses the DFN1110D-3 (SOT8015) ultra-thin leadless package: 1.1 mm × 1.0 mm × 0.48 mm body, 0.65 mm pitch, side-wettable flanks for automated optical inspection. Package height is 0.5 mm, enabling use in ultra-low-profile assemblies.

Pin/Terminal	Circuit Role	Design Meaning
1	Base (B)	Control terminal for forward-biased PNP operation; requires negative base current relative to emitter to turn on.
2	Emitter (E)	Current source terminal; connected to higher potential rail in high-side switch configurations.
3	Collector (C)	Current sink terminal; delivers load current to ground or lower-potential node when saturated.

Key Features

Feature	Design Value
AEC-Q101 qualified	Validated for automotive applications including body control modules and lighting systems per discrete semiconductor stress test standard.
Side-wettable flanks	Enables reliable Automated Optical Inspection (AOI) of solder joints without X-ray, reducing post-reflow defect escape in high-volume SMT lines.
Ultra-small footprint	1.1 mm × 1.0 mm area - 60% smaller than SOT23, freeing PCB space in wearables, smart sensors, and compact ECUs.
Low profile (0.48 mm height)	Permits stacking under shields or integration into slim enclosures where Z-axis clearance is constrained to ≤ 0.6 mm.
High h_FE bin (B-grade)	220–475 gain range reduces required base drive current by ≥2× versus A-grade (125–250), lowering MCU GPIO loading.

Applications

Automotive Interior Lighting Control

Portable Sensor Signal Conditioning

Use Scenario: Driving 20 mA white LEDs in door handle illumination modules with PWM dimming.

IC Role / Device Role / Timing Role: PNP high-side switch controlled by microcontroller GPIO; provides rail-to-rail current sourcing with fast turn-off via base pull-up.

Use Value: Low V_CEsat (< −650 mV) minimizes voltage drop across transistor, preserving LED forward voltage margin and enabling 3.3 V supply operation.

Use Scenario: Amplifying weak thermistor or Hall-effect sensor outputs in battery-powered IoT nodes.

IC Role / Device Role / Timing Role: Common-emitter amplifier stage with fixed bias network; provides 20–30 dB voltage gain for analog front-end conditioning.

Use Value: High h_FE (220–475) ensures stable DC operating point despite ±15% resistor tolerances and temperature drift.

Industrial Pushbutton Interface

Consumer Appliance Power Sequencing

Use Scenario: Debouncing and level-shifting mechanical pushbutton signals from 24 V industrial rails to 3.3 V microcontrollers.

IC Role / Device Role / Timing Role: Inverting level translator with Schmitt-trigger input behavior achieved via emitter-follower + resistive feedback.

Use Value: −45 V V_CEO withstands inductive kickback from adjacent solenoids, eliminating need for external clamping diodes.

Use Scenario: Enabling 5 V auxiliary rails only after main 12 V supply stabilizes in smart home hubs.

IC Role / Device Role / Timing Role: Delayed-enable PNP switch triggered by RC time constant on base; provides clean power-up sequencing.

Use Value: Low leakage (I_CBO ≤ −5 µA at 150 °C) prevents false turn-on during hot storage, ensuring reliable cold-start behavior.

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,115 (Nexperia)	SOT323 package (2.1 mm × 1.25 mm); no side-wettable flanks; h_FE 220–475 same bin; V_CEO = −45 V.	Larger footprint and non-AOI-friendly; suitable for prototyping or legacy board designs with SOT323 footprints.	Select when AOI capability is unnecessary and existing SOT323 layout reuse is prioritized over miniaturization.
MMBT857LT1G (onsemi)	SOT-23 package; h_FE 200–450; V_CEO = −45 V; AEC-Q101 qualified; no side-wettable flanks.	Standard SMT assembly compatibility but lacks AOI support; slightly lower max f_T (80 MHz vs. 100 MHz).	Choose for cost-sensitive industrial applications where DFN handling infrastructure is unavailable and AOI is not mandated.

Compared with BC857BW,115 and MMBT857LT1G, BC857BQB-Q uniquely combines AEC-Q101 qualification, side-wettable flanks for production AOI, and the smallest footprint (1.1 mm × 1.0 mm), making it optimal for next-generation automotive and space-constrained consumer electronics requiring zero-defect solder joint verification.

Availability

BC857BQB-Q is available at Aetrix Electronics and suitable for automotive interior lighting control, portable sensor signal conditioning, and industrial pushbutton interface applications requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for BC857BQB-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 technologies, delivering high-performance, reliable discrete, logic, and MOSFET devices for automotive, industrial, and mobile markets.

The BC857xQB-Q series belongs to Nexperia's AEC-Q101-qualified general-purpose transistor product line, engineered specifically for space-constrained automotive and industrial applications demanding AOI-compatible packaging and robust parametric stability across temperature.

FAQ

Is BC857BQB-Q suitable for automotive applications?

Yes - BC857BQB-Q is fully qualified per AEC-Q101 for discrete semiconductors, including stress tests for temperature cycling, humidity, and high-temperature operating life. It is recommended for automotive body electronics, lighting, and sensor interfaces where junction temperature may reach 150 °C and solder joint reliability is critical.

What is the maximum allowable base current for continuous operation?

The absolute maximum peak base current is −100 mA (single pulse, t_p ≤ 1 ms), but for continuous DC operation, base current must be limited to ensure I_C ≤ −100 mA and P_tot ≤ 420 mW. At I_C = −100 mA and h_FE = 220, typical I_B is −455 µA; design margins recommend limiting I_B to ≤ −1 mA for thermal safety.

How does the side-wettable flank feature improve manufacturing yield?

Side-wettable flanks expose solderable metal along the package edge, allowing automated optical inspection systems to verify solder fillet formation and wetting quality without X-ray. This eliminates blind spots inherent in bottom-terminated DFN packages and reduces field returns due to head-in-pillow or insufficient solder joint defects in high-volume SMT lines.

Can BC857BQB-Q replace BC857B in existing SOT23 designs?

No - BC857BQB-Q uses DFN1110D-3 (SOT8015), which is not pin-compatible or footprint-compatible with SOT23. The pin order (B-E-C vs. E-B-C) and pad geometry differ fundamentally. Migration requires PCB redesign, stencil revision, and requalification; it is not a drop-in replacement.

BC857BQB-QZ Specifications

Product attributes: Attribute value

Manufacturer:: Nexperia USA Inc.

Series:: -

Package/Case:: 3-XDFN Exposed Pad

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:: 650mV @ 5mA, 100mA

Current - Collector Cutoff (Max):: 15nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 220 @ 2mA, 5V

Power - Max:: 340 mW

Frequency - Transition:: 100MHz

Operating Temperature:: 150°C (TJ)

Grade:: Automotive

Qualification:: AEC-Q101

Mounting Type:: Surface Mount, Wettable Flank

Supplier Device Package:: DFN1110D-3

BC857BQB-QZ FAQ

1.How can I place an order for BC857BQB-QZ through Aetrix?

Please submit a Request for Quotation (RFQ) for BC857BQB-QZ 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 BC857BQB-QZ reliable?

The price and inventory of BC857BQB-QZ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC857BQB-QZ is usually 5 days.

3.What payment methods are accepted for BC857BQB-QZ?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC857BQB-QZ transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BC857BQB-QZ?

BC857BQB-QZ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BC857BQB-QZ 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 BC857BQB-QZ?

For technical support, including BC857BQB-QZ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC857BQB-QZ requirements.

6.How does Aetrix verify that BC857BQB-QZ is sourced from the original manufacturer or authorized distributors?

All BC857BQB-QZ 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 BC857BQB-QZ meets industry standards.

7.What is the process for return or replacement of BC857BQB-QZ?

All BC857BQB-QZ units undergo pre-shipment inspection (PSI). If there is an issue with BC857BQB-QZ, 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 BC857BQB-QZ part is unused and in its original packaging.

Return procedure for BC857BQB-QZ:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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