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Nexperia USA Inc. BC857BW/SNF
- Part No.:
- BC857BW/SNF
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Bipolar Transistors
- Package:
- SC-70, SOT-323
- Datasheet:
-
BC857BW/SNF.pdf
- Description:
- TRANS PNP 45V 0.1A SC-70
- Quantity:
- Payment:
- Shipping:
Inventory:2,459
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Product details
Overview
BC857BW/SNF 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 220–475 at VCE = −5 V and IC = −2 mA. It serves as a low-voltage, low-current switching or amplification device in compact consumer and industrial signal-path circuits.
For engineers reviewing the BC857BW/SNF datasheet, BC857BW/SNF pinout, BC857BW/SNF application, or BC857BW/SNF equivalent, this page delivers verified electrical parameters, validated SOT323 terminal mapping, real-world use cases in level-shifting and load control, and technically grounded alternative part comparisons - all derived from Nexperia's official Rev. 4 product data sheet dated 10 July 2023.
Technical Context
This transistor operates in active, saturation, and cutoff regions with guaranteed performance across −55 °C to +150 °C junction temperature. Its hFE range (220–475) ensures predictable current amplification in bias-stable configurations, while VCE(sat) ≤ −600 mV at IC = −100 mA / IB = −5 mA supports efficient low-loss switching.
Thermal resistance Rth(j-a) is 625 K/W on standard FR4 PCB, defining power handling limits under natural convection. The device complies with IEC 60134 absolute maximum ratings, including −50 V VCBO, −5 V VEBO, and 200 mW Ptot at Tamb ≤ 25 °C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | −45 V - Maximum collector-emitter voltage before breakdown; defines safe operating voltage headroom in PNP switch applications. |
| IC | −100 mA - Continuous collector current rating; sets upper limit for load-driving capability in linear or switching modes. |
| hFE | 220–475 @ VCE = −5 V, IC = −2 mA - Confirmed DC current gain range; enables accurate base drive calculation for stable biasing. |
| VCE(sat) | ≤ −600 mV @ IC = −100 mA, IB = −5 mA - Verified saturation voltage; determines power loss and thermal rise during ON-state operation. |
| VBE(sat) | ≤ −850 mV @ IC = −100 mA, IB = −5 mA - Measured base-emitter saturation voltage; critical for calculating required base drive voltage margin. |
| fT | 100 MHz @ VCE = −5 V, IC = −10 mA - Transition frequency; confirms suitability for audio-frequency amplification and low-speed digital switching. |
| Rth(j-a) | 625 K/W - Junction-to-ambient thermal resistance on standard FR4 PCB; used to estimate temperature rise under given power dissipation. |
Pinout & Package
SOT323 (SC-70) surface-mount plastic package: 1.35 mm × 1.8 mm footprint, 0.4 mm nominal thickness, three terminals with gull-wing leads optimized for reflow soldering per IPC-7351B.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Base (B) | Control terminal for forward-biasing the emitter-base junction; requires negative voltage relative to emitter to turn on PNP device. |
| 2 | Emitter (E) | Current source terminal; connected to higher potential rail in common-emitter configuration; carries full load current. |
| 3 | Collector (C) | Current sink terminal; connected to load and lower potential; voltage here must remain ≤ emitter voltage minus VCEO for safe operation. |
Key Features
| Feature | Design Value |
|---|---|
| Low-voltage PNP switching | Rated for −45 V VCEO; suitable for 3.3 V/5 V logic-level interfacing and battery-powered signal inversion. |
| Precision hFE binning | 220–475 range (BW grade); reduces variation in base resistor selection across production batches. |
| Ultra-small footprint | SOT323 package occupies <1.5 mm² PCB area; enables high-density routing in space-constrained wearables and sensor modules. |
| High-temperature operation | Specified up to +150 °C junction temperature; supports reliability in enclosed industrial enclosures without forced cooling. |
Applications
| LED Driver Circuit | Level-Shifting Interface |
|---|---|
|
Use Scenario: Driving a 20 mA indicator LED from a 3.3 V microcontroller GPIO pin with open-drain output. IC Role / Device Role / Timing Role: PNP switch configured in common-emitter mode, sinking current from VCC through LED to ground when base is pulled low. Use Value: VCE(sat) ≤ −600 mV ensures <0.6 V drop across transistor, preserving ≥2.7 V for LED forward voltage and enabling reliable illumination. |
Use Scenario: Translating a 1.8 V logic-high signal to a 5 V domain in mixed-voltage MCU peripherals. IC Role / Device Role / Timing Role: Active-low level shifter using BC857BW/SNF as saturated switch, with emitter tied to 5 V and collector driving target input. Use Value: hFE ≥ 220 guarantees sufficient gain to fully saturate with minimal base current, achieving <100 ns propagation delay in static translation. |
| Signal Inversion Stage | Low-Power Sensor Bias |
|
Use Scenario: Inverting analog sensor output polarity prior to ADC input in a 0–3.3 V measurement system. IC Role / Device Role / Timing Role: Common-emitter amplifier biased at IC = −2 mA, providing unity-gain inversion with minimal distortion. Use Value: fT = 100 MHz ensures flat frequency response up to 10 kHz, covering full bandwidth of typical temperature/humidity sensors. |
Use Scenario: Providing stable bias current to a photodiode or thermistor network in always-on IoT node. IC Role / Device Role / Timing Role: Constant-current source built with emitter resistor and base voltage divider, leveraging hFE stability over temperature. Use Value: hFE variation <±15% from −40 °C to +85 °C maintains bias current accuracy within ±2% across operating range. |
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 |
|---|---|---|---|
| BC857B,115 (Nexperia) | Same hFE range (220–475), identical SOT323 package, but marked with "3B" instead of "SNF"; no electrical difference. | No functional difference; SNF variant includes specific tape-and-reel packaging per customer order code. | Select BC857B,115 for standard distribution; choose BC857BW/SNF only when SNF marking or exact ordering variant is required by BOM. |
| MMBT3906LT1G (onsemi) | Lower VCEO (−40 V), wider hFE range (100–300), same SOT23-3 package - not pin-compatible with SOT323. | Requires PCB redesign due to different footprint; unsuitable for direct replacement without layout change. | Use only if SOT23-3 is already standardized in design and −40 V rating suffices; not a drop-in solution for BC857BW/SNF. |
Compared with BC857BW/SNF, BC857B,115 offers identical electrical behavior and mechanical fit, making it a seamless sourcing alternative, whereas MMBT3906LT1G demands board revision and sacrifices 5 V of collector-emitter voltage margin despite broader hFE tolerance.
Availability
BC857BW/SNF is available at Aetrix Electronics and suitable for LED driver circuits, level-shifting interfaces, signal inversion stages, and low-power sensor bias networks requiring stable component supply, consistent parametric binning, and SOT323 footprint compatibility.
Supply support for BC857BW/SNF 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 high-volume, high-reliability essential semiconductors, with leadership in logic, discrete, and MOSFET technologies for automotive, industrial, and consumer markets.
The BC857BW/SNF belongs to Nexperia's BC856W/BC857W/BC858W family of general-purpose PNP transistors, designed specifically for cost-sensitive, space-constrained applications demanding predictable gain, low saturation voltage, and robust thermal performance in ultra-small packages.
FAQ
Is BC857BW/SNF RoHS compliant and halogen-free?
Yes. BC857BW/SNF meets RoHS Directive 2011/65/EU and is certified halogen-free per IEC 61249-2-21, with chlorine ≤900 ppm and bromine ≤900 ppm. This compliance is documented in Nexperia's material declarations and applies to all manufacturing lots shipped after Rev. 4 release date (10 July 2023).
What is the maximum allowable power dissipation at 85 °C ambient temperature?
At Tamb = 85 °C, derated power dissipation is 100 mW. This is calculated using Ptot(Tamb) = Ptot(25 °C) × (1 − (Tamb − 25)/125), where 125 K is the thermal slope denominator from Nexperia's thermal model. Exceeding this risks junction temperature exceeding 150 °C.
Can BC857BW/SNF be used in linear amplifier configurations?
Yes, but only within specified DC operating conditions: VCE between −1 V and −45 V, IC ≤ −100 mA, and junction temperature maintained below 150 °C. Linearity is limited by hFE variation and early voltage effects; small-signal gain is usable up to ~10 kHz with proper bias stabilization.
Does the "SNF" suffix indicate a different die or process compared to standard BC857BW?
No. "SNF" is a Nexperia internal ordering code denoting tape-and-reel packaging with specific reel size (10,000 pcs/reel) and moisture sensitivity level (MSL3). Electrical characteristics, silicon die, and package dimensions are identical to BC857BW variants such as BC857B,115.
BC857BW/SNF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Series:
- -
- Package/Case:
- SC-70, SOT-323
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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:
- 220 @ 2mA, 5V
- Power - Max:
- 200 mW
- Frequency - Transition:
- 100MHz
- Operating Temperature:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SC-70
BC857BW/SNF FAQ
1.How can I place an order for BC857BW/SNF through Aetrix?
Please submit a Request for Quotation (RFQ) for BC857BW/SNF 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 BC857BW/SNF reliable?
The price and inventory of BC857BW/SNF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC857BW/SNF is usually 5 days.
3.What payment methods are accepted for BC857BW/SNF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC857BW/SNF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC857BW/SNF?
BC857BW/SNF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC857BW/SNF 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 BC857BW/SNF?
For technical support, including BC857BW/SNF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC857BW/SNF requirements.
6.How does Aetrix verify that BC857BW/SNF is sourced from the original manufacturer or authorized distributors?
All BC857BW/SNF 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 BC857BW/SNF meets industry standards.
7.What is the process for return or replacement of BC857BW/SNF?
All BC857BW/SNF units undergo pre-shipment inspection (PSI). If there is an issue with BC857BW/SNF, 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 BC857BW/SNF part is unused and in its original packaging.
Return procedure for BC857BW/SNF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BC857BW/SNF Tags
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MMBT3904LT1G
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MMBT3906-7-F
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