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Diodes Incorporated BC857BFA-7B
- Part No.:
- BC857BFA-7B
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Bipolar Transistors
- Package:
- 3-XFDFN
- Datasheet:
-
BC857BFA-7B.pdf
- Description:
- TRANS PNP 45V 0.1A X2-DFN0806-3
- Quantity:
- Payment:
- Shipping:
Inventory:8,849
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Product details
Overview
BC857BFA-7B from Diodes Incorporated is a 45V PNP small-signal transistor in X2-DFN0806-3 package, rated for -100mA continuous collector current and 435mW power dissipation. It features -45V VCEO, DC current gain (hFE) of 200–470 at IC = -2mA to -10mA, and VCE(sat) as low as -70mV at IC = -10mA/IB = -0.5mA. Used in compact biasing, level-shifting, and load-switching circuits in automotive body control modules.
For engineers reviewing the BC857BFA-7B datasheet, BC857BFA-7B pinout, BC857BFA-7B application, or BC857BFA-7B equivalent, key selection criteria include its AEC-Q101 qualification, ultra-small 0.48mm² footprint, NiPdAu terminal finish, -55°C to +150°C operating range, and complementary pairing with BC847BFA.
Technical Context
This PNP bipolar junction transistor operates in active, saturation, and cutoff regions with verified breakdown ratings: VCBO = -50V, VCEO = -45V, and VEBO = -6.0V. Its fT = 100–340MHz enables use in low-frequency switching and analog amplification up to ~100MHz.
Thermal design is supported by RθJA = 287°C/W (on 1oz FR4) and RθJL = 150°C/W to the exposed collector pad. ESD robustness includes 4kV HBM and 200V MM ratings per JEDEC JESD22-A114/A115.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | -45V - Maximum allowable collector-emitter voltage before breakdown under open-base condition; defines safe operating voltage headroom in high-side switch applications. |
| IC (cont.) | -100mA - Continuous collector current rating; supports moderate-load switching without derating at TA ≤ 75°C on standard PCB layout. |
| PD | 435mW - Power dissipation limit at TA = +25°C; requires thermal pad connection to PCB copper for full rating utilization. |
| hFE | 200–470 - DC current gain range at IC = -2mA to -10mA/VCE = -5V; ensures predictable base drive requirements across production lots. |
| VCE(sat) | -70mV to -500mV - Saturation voltage span across IC = -10mA to -100mA; enables low-loss switching in battery-powered logic interfaces. |
| fT | 100–340MHz - Current gain-bandwidth product at VCE = -5V/IC = -10mA; confirms suitability for RF front-end biasing and fast digital switching. |
| ESD HBM | 4,000V - Human Body Model rating per JESD22-A114; reduces risk of assembly-line damage during SMT handling and rework. |
Pinout & Package
Package: X2-DFN0806-3 - 0.60mm × 0.80mm, 0.4mm height, molded green compound (UL 94V-0), exposed collector pad on bottom surface. Terminals: NiPdAu finish, solderable per MIL-STD-202 Method 208.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Top-left, marked side) | Emitter (E) | Current exit node in PNP operation; connects to higher-potential rail in high-side switch configurations. |
| 2 (Top-right) | Base (B) | Control input; requires current-limited drive (e.g., via 10kΩ resistor) to achieve specified hFE and VCE(sat). |
| 3 (Bottom, exposed pad) | Collector (C) | Main current path; electrically and thermally connected to PCB copper pour for power dissipation and signal return. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-compact footprint | 0.48mm² area - 16× smaller than SOT-23; enables dense routing in space-constrained automotive ECUs and wearables. |
| AEC-Q101 qualification | Qualified for automotive-grade reliability - supports deployment in non-safety-critical vehicle subsystems without additional qualification effort. |
| Green construction | Halogen- and antimony-free (<900ppm Br/Cl, <1000ppm Sb); meets global environmental compliance mandates including RoHS 2 and ELV. |
| Low-profile packaging | 0.4mm max height - minimizes Z-axis stack-up in multi-layer modules and thin-form-factor IoT sensors. |
| Complementary NPN pairing | Matched performance with BC847BFA - simplifies dual-rail driver design and differential amplifier implementation. |
Applications
| Automotive Body Control Unit | Industrial Sensor Interface |
|---|---|
|
Use Scenario: Driving LED indicators and relay coils in door module PCBs with 12V supply rails. IC Role / Device Role / Timing Role: High-side PNP switch controlling current flow from battery to load; operates in saturation with <100µs turn-on/off. Use Value: Low VCE(sat) (-70mV typ.) minimizes power loss and heat generation in thermally restricted enclosures. |
Use Scenario: Level-shifting 3.3V microcontroller GPIO signals to interface with 5V/12V industrial sensors. IC Role / Device Role / Timing Role: Active-low translator providing inverted logic output with rail-to-rail swing and sub-100ns propagation delay. Use Value: Guaranteed hFE ≥ 200 ensures reliable switching even with marginal base drive at temperature extremes. |
| Portable Medical Monitor | Smart Home Actuator Driver |
|
Use Scenario: Biasing op-amp input stages and photodiode transimpedance amplifiers in battery-powered vital sign monitors. IC Role / Device Role / Timing Role: Linear-mode current source/sink for precision analog signal conditioning; operates in active region with stable hFE. Use Value: Tight VBE(on) spread (-600mV to -850mV) enables accurate current setting without trimming resistors. |
Use Scenario: Controlling solenoid valves and small DC motors in Wi-Fi-enabled HVAC actuators. IC Role / Device Role / Timing Role: Medium-current load switch interfacing MCU PWM outputs to inductive loads with flyback protection. Use Value: -45V VCEO withstands inductive kickback spikes up to 40V, eliminating need for external clamp diodes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PNP small-signal transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BC857BW,115 (Nexperia) | SOT-323 package (1.3mm × 1.3mm), higher RθJA = 375°C/W, hFE = 200–450, same VCEO/IC. | Larger footprint and lower thermal efficiency; suitable only where board space permits and power dissipation <300mW. | Select when legacy SOT-323 compatibility is required and thermal margin exists. |
| MMBT3906LT1G (ON Semiconductor) | SOT-23 package (2.9mm × 1.3mm), VCEO = -40V, IC = -200mA, hFE = 100–300, no AEC-Q101 qualification. | Higher current but lower voltage rating and no automotive qualification; wider VCE(sat) spread (-100mV to -600mV). | Choose for cost-sensitive industrial applications where AEC-Q101 is not mandated and board area is unconstrained. |
Compared with BC857BW and MMBT3906LT1G, BC857BFA-7B offers superior thermal performance per unit area, AEC-Q101 assurance, and smallest footprint-making it optimal for next-gen automotive and portable electronics where size, reliability, and thermal density are critical.
Availability
BC857BFA-7B is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor interfaces, and portable medical monitoring systems requiring stable component supply, long-term lifecycle support, and consistent AEC-Q101-compliant performance.
Supply support for BC857BFA-7B 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability components for automotive, industrial, and consumer markets with over 50 years of device engineering heritage.
The BC857BFA belongs to Diodes' AEC-Q101-qualified small-signal transistor family, engineered specifically for space-constrained, thermally demanding automotive and industrial control applications requiring robust parametric stability across temperature.
FAQ
What is the maximum operating temperature for BC857BFA-7B?
The BC857BFA-7B is rated for junction and storage temperatures from -55°C to +150°C. Its thermal resistance (RθJA = 287°C/W) allows full 435mW power dissipation only at ambient ≤25°C on recommended PCB layout; derating is required above that, reaching zero power at ~150°C ambient.
Is BC857BFA-7B compatible with lead-free reflow profiles?
Yes - BC857BFA-7B uses NiPdAu-plated terminals and green molding compound qualified for standard lead-free reflow (JEDEC J-STD-020 Level 1 moisture sensitivity). Peak temperature tolerance is 260°C for 30 seconds, matching IPC/JEDEC Class 3 assembly requirements.
How does the X2-DFN0806-3 package affect PCB layout?
The X2-DFN0806-3 requires precise 0.35mm × 0.20mm solder pads with 0.25mm spacing, plus an exposed collector thermal pad connected to ≥1cm² internal/external copper pour. Misalignment or insufficient paste volume risks tombstoning or thermal failure due to its 0.4mm height and fine pitch.
Can BC857BFA-7B replace BC857C in existing designs?
No - BC857BFA-7B has hFE = 200–470 (B-grade), while BC857C specifies hFE = 420–800. Substituting may cause insufficient gain in high-β-dependent circuits like low-noise preamps; verify hFE margin and VCE(sat) impact before replacement.
BC857BFA-7B Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- 3-XFDFN
- 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:
- 500mV @ 5mA, 100mA
- Current - Collector Cutoff (Max):
- 15nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 200 @ 2mA, 5V
- Power - Max:
- 435 mW
- Frequency - Transition:
- 340MHz
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- X2-DFN0806-3
BC857BFA-7B FAQ
1.How can I place an order for BC857BFA-7B through Aetrix?
Please submit a Request for Quotation (RFQ) for BC857BFA-7B 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 BC857BFA-7B reliable?
The price and inventory of BC857BFA-7B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC857BFA-7B is usually 5 days.
3.What payment methods are accepted for BC857BFA-7B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC857BFA-7B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC857BFA-7B?
BC857BFA-7B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC857BFA-7B 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 BC857BFA-7B?
For technical support, including BC857BFA-7B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC857BFA-7B requirements.
6.How does Aetrix verify that BC857BFA-7B is sourced from the original manufacturer or authorized distributors?
All BC857BFA-7B 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 BC857BFA-7B meets industry standards.
7.What is the process for return or replacement of BC857BFA-7B?
All BC857BFA-7B units undergo pre-shipment inspection (PSI). If there is an issue with BC857BFA-7B, 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 BC857BFA-7B part is unused and in its original packaging.
Return procedure for BC857BFA-7B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BC857BFA-7B Tags
-
MMBT3906LT1G
onsemi
-
MMBT3904-7-F
Diodes Incorporated
-
MMBT3904LT1G
onsemi
-
MMBT3906-7-F
Diodes Incorporated
-
MMBT3904-TP
Micro Commercial Co
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MMBT2222A-7-F
Diodes Incorporated
-
BC846BLT1G
onsemi
-
BC847B,215
Nexperia USA Inc.
-
SMMBT3904LT1G
onsemi
-
MMBT2222A-TP
Micro Commercial Co
-
MMBTA06LT1G
onsemi
-
MMBT2222ALT1G
onsemi
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