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

Nexperia USA Inc. BC857BQBZ

Name: BC857BQBZ
Brand: Nexperia USA Inc.
SKU: BC857BQBZ
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BC857BQBZ

Manufacturer:: Nexperia USA Inc.

Category:: Single Bipolar Transistors

Package:: 3-XDFN Exposed Pad

Datasheet:: BC857BQBZ.pdf

Description:: TRANS 45V 0.1A DFN1110D-3

Quantity:: RFQ Add To RFQ list

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Product details

Overview

BC857BQBZ from Nexperia is a PNP general-purpose transistor in an ultra-small DFN1110D-3 (SOT8015) leadless SMD package with side-wettable flanks, 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 serves as a compact, AEC-Q101-qualified switching or amplification device in space-constrained automotive and industrial control circuits.

For engineers reviewing the BC857BQBZ datasheet, BC857BQBZ pinout, BC857BQBZ application, or BC857BQBZ equivalent, key selection criteria include its low-profile 0.48 mm height, side-wettable flanks for AOI-compatible solder joint inspection, −650 mV V_CEsat at I_C = −100 mA / I_B = −5 mA, thermal resistance of 298 K/W on 70 µm FR4 PCB, and automotive-grade reliability per AEC-Q101.

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 biasing in negative-rail signal conditioning and load-switching topologies. Its h_FE range (220–475) enables stable DC amplification across −2 mA to −100 mA collector currents while maintaining predictable saturation behavior.

The DFN1110D-3 package integrates side-wettable flanks for automated optical inspection of solder joints and achieves 0.5 mm maximum package height-critical for ultra-thin consumer and automotive modules. Thermal performance is specified for both 35 µm and 70 µm copper FR4 PCBs, with P_tot derated from 420 mW at 25 °C to zero at 150 °C junction temperature.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	−45 V - Maximum safe collector-emitter voltage with base open; defines rail tolerance in high-side switch configurations.
I_C	−100 mA - Continuous DC collector current rating; supports medium-current logic-level switching and sensor interface buffering.
h_FE	220–475 at V_CE = −5 V, I_C = −2 mA - Ensures reliable base drive margin for gain-stable amplification in analog front-ends.
V_CEsat	−650 mV max at I_C = −100 mA, I_B = −5 mA - Low saturation voltage minimizes power loss and heat generation in switching applications.
P_tot	420 mW on FR4 PCB with 70 µm copper - Enables operation up to 125 °C ambient without forced cooling in sealed enclosures.
T_j max	150 °C - Junction temperature limit compatible with automotive under-hood environments per AEC-Q101.
R_th(j-a)	298 K/W - Thermal resistance from junction to ambient on standard 70 µm FR4; informs heatsinking requirements for sustained loads.

Pinout & Package

DFN1110D-3 (SOT8015) is a 3-terminal, leadless, ultra-thin plastic package measuring 1.1 mm × 1.0 mm × 0.48 mm with 0.65 mm pitch and side-wettable flanks for AOI-compatible reflow soldering.

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 in PNP configuration; typically connected to higher potential rail in high-side switch layouts.
3	Collector (C)	Current sink terminal; connects to load and lower-potential node; handles full switched current up to −100 mA.

Key Features

Feature	Design Value
AEC-Q101 qualification	Validated for automotive applications including engine control modules and body electronics requiring extended temperature and reliability compliance.
Side-wettable flanks	Enables 100% automated optical inspection (AOI) of solder joints without X-ray, reducing post-solder defect escapes in high-volume manufacturing.
0.48 mm package height	Supports ultra-low-profile designs such as wearable sensors, slim automotive lighting controllers, and stacked PCB assemblies.
−6 V V_EBO	Allows safe biasing with common microcontroller GPIOs (e.g., 3.3 V or 5 V rails) when emitter is tied to supply and base driven through resistor.
220–475 h_FE range	Provides consistent gain across production lots, simplifying base resistor selection for predictable switching thresholds in discrete logic interfaces.

Applications

Automotive Door Module Switching

Portable Medical Sensor Biasing

Use Scenario: Controlling LED status indicators and small solenoid locks in vehicle door control units where board space is limited and ambient temperature exceeds 105 °C.

IC Role / Device Role / Timing Role: PNP high-side switch driving 20 mA indicator LEDs from 12 V battery rail using MCU GPIO-controlled base pull-down.

Use Value: −650 mV V_CEsat limits power dissipation to <13 mW per LED channel, enabling fanless operation in sealed modules.

Use Scenario: Providing stable bias current to low-power analog front-end op-amps and Hall-effect sensors in handheld ECG monitors.

IC Role / Device Role / Timing Role: Precision current source configured in emitter-follower mode to deliver regulated 1–5 mA sensor excitation current.

Use Value: Tight h_FE spread (220–475) and −6 V V_EBO ensure ±2% current accuracy over −40 to +85 °C without trimming resistors.

Industrial PLC Input Protection

Smart Home Motion Detector Interface

Use Scenario: Level-shifting and isolating 24 V digital inputs from field devices into 3.3 V microcontroller I/O pins in programmable logic controllers.

IC Role / Device Role / Timing Role: Discrete PNP buffer stage converting sinking 24 V signals to sourcing 3.3 V logic levels with galvanic separation via optocoupler driver.

Use Value: −45 V V_CEO withstands industrial transients and surge events per IEC 61000-4-4, eliminating need for external TVS diodes.

Use Scenario: Enabling ultra-low-power wake-up circuitry in battery-operated PIR motion detectors by holding RF transceiver in deep sleep until triggered.

IC Role / Device Role / Timing Role: Low-leakage PNP switch disconnecting V_DD from transceiver IC during standby; I_CBO ≤ −15 nA ensures <1 µA total system quiescent current.

Use Value: −15 nA I_CBO at 25 °C and −5 µA at 150 °C extends coin-cell battery life beyond 2 years in always-on sensing nodes.

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 × 0.95 mm); no side-wettable flanks; h_FE 220–475 identical; P_tot = 250 mW.	Larger footprint and higher profile; unsuitable for AOI or ultra-thin assemblies; lower power handling limits continuous current to ~60 mA.	Select when legacy SOT323 layout compatibility is required and AOI is not mandated.
MMBT3906LT1G (onsemi)	SOT-23 package (3.0 mm × 1.4 mm × 1.1 mm); h_FE 100–300; V_CEO = −40 V; V_CEsat = −400 mV typical at I_C = −10 mA.	Higher V_CEsat at high current (−700 mV @ −100 mA), lower max voltage, non-AEC-Q101 qualified; lacks side-wettable flanks.	Select for cost-sensitive consumer applications where AEC-Q101 and AOI are unnecessary and board space allows SOT-23.

Compared with BC857BW,115, BC857BQBZ delivers 68% smaller footprint and 68% lower profile with AOI support and +68% power capability; versus MMBT3906LT1G, it offers tighter h_FE, higher V_CEO, AEC-Q101 compliance, and manufacturability advantages in automotive and space-constrained designs.

Availability

BC857BQBZ is available at Aetrix Electronics and suitable for automotive body electronics, portable medical instrumentation, industrial PLC input stages, and smart home sensor hubs requiring stable component supply with guaranteed long-term continuity.

Supply support for BC857BQBZ 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 solutions for automotive, industrial, and mobile markets.

The BC857xQB series targets space-constrained, high-reliability applications demanding AEC-Q101 qualification, ultra-small packaging, and AOI-compatible assembly-designed specifically for next-generation automotive ECUs and miniaturized industrial controls.

FAQ

Is BC857BQBZ pin-compatible with BC857B,115 or BC857BW,115?

No. BC857BQBZ uses the DFN1110D-3 (SOT8015) package with side-wettable flanks and a 1.1 mm × 1.0 mm footprint, whereas BC857B,115 and BC857BW,115 use larger SOT363 and SOT323 packages respectively. Pin numbering differs, and land patterns are incompatible-PCB redesign is required for substitution.

What is the maximum allowable base current for continuous operation?

The absolute maximum peak base current is −100 mA per datasheet Table 6, but for continuous DC operation, base current must be limited to ensure junction temperature remains ≤150 °C. At I_C = −100 mA and h_FE = 220, I_B ≈ −455 µA; practical design uses I_B = −5 mA for robust saturation, well within safe limits given P_tot derating curves.

Does BC857BQBZ support reflow soldering per JEDEC J-STD-020?

Yes. The DFN1110D-3 package is qualified for standard lead-free reflow profiles per JEDEC J-STD-020, with peak temperature up to 260 °C. Figure 17 in the datasheet provides the recommended stencil thickness (0.1 mm), solder paste volume, and land pattern dimensions for reliable solder joint formation on side-wettable flanks.

How does the −6 V V_EBO rating impact interfacing with 3.3 V microcontrollers?

With emitter tied to 3.3 V, the −6 V V_EBO rating allows up to 9.3 V differential between base and emitter before breakdown-more than sufficient for standard GPIO-driven base resistors. For example, a 10 kΩ pull-down from base to GND yields ~0.33 mA base current at 3.3 V, safely within linear operating region and avoiding reverse-bias damage.

BC857BQBZ Specifications

Product attributes: Attribute value

Manufacturer:: Nexperia USA Inc.

Series:: -

Package/Case:: 3-XDFN Exposed Pad

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Transistor Type:: -

Current - Collector (Ic) (Max):: 100 mA

Voltage - Collector Emitter Breakdown (Max):: 45 V

Vce Saturation (Max) @ Ib, Ic:: 400mV @ 5mA, 100mA

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

DC Current Gain (hFE) (Min) @ Ic, Vce:: 200 @ 2mA, 5V

Power - Max:: 340 mW

Frequency - Transition:: -

Operating Temperature:: 150°C (TJ)

Grade:: Automotive

Qualification:: AEC-Q101

Mounting Type:: Surface Mount, Wettable Flank

Supplier Device Package:: DFN1110D-3

BC857BQBZ FAQ

1.How can I place an order for BC857BQBZ through Aetrix?

Please submit a Request for Quotation (RFQ) for BC857BQBZ 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 BC857BQBZ reliable?

The price and inventory of BC857BQBZ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC857BQBZ is usually 5 days.

3.What payment methods are accepted for BC857BQBZ?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC857BQBZ transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BC857BQBZ?

BC857BQBZ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BC857BQBZ 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 BC857BQBZ?

For technical support, including BC857BQBZ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC857BQBZ requirements.

6.How does Aetrix verify that BC857BQBZ is sourced from the original manufacturer or authorized distributors?

All BC857BQBZ 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 BC857BQBZ meets industry standards.

7.What is the process for return or replacement of BC857BQBZ?

All BC857BQBZ units undergo pre-shipment inspection (PSI). If there is an issue with BC857BQBZ, 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 BC857BQBZ part is unused and in its original packaging.

Return procedure for BC857BQBZ:

1.Submit a request within 90 days.

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

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