Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

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

Nexperia USA Inc. BC857CW/DG/B4F

Name: BC857CW/DG/B4F
Brand: Nexperia USA Inc.
SKU: BC857CW/DG/B4F
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: BC857CW/DG/B4F

Manufacturer:: Nexperia USA Inc.

Category:: Single Bipolar Transistors

Package:: SC-70, SOT-323

Datasheet:: BC857CW/DG/B4F.pdf

Description:: TRANS PNP 45V 0.1A SC-70

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:7,948

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

BC857CW/DG/B4F from Nexperia is a PNP general-purpose bipolar junction transistor in SOT323 (SC-70) package, rated for −45 V V_CEO, −100 mA I_C, and DC current gain (h_FE) of 420–800 at V_CE = −5 V and I_C = −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 BC857CW/DG/B4F datasheet, BC857CW/DG/B4F pinout, BC857CW/DG/B4F application, or BC857CW/DG/B4F equivalent, key selection criteria include its guaranteed high h_FE band, SOT323 footprint compatibility, −45 V breakdown rating, and thermal resistance of 625 K/W on FR4 PCB - all critical for space-constrained biasing, level-shifting, and discrete logic interface designs.

Technical Context

This PNP BJT operates in active or saturation mode with base-emitter turn-on voltage (V_BE) of −650 mV typical at I_C = −10 mA, and collector-emitter saturation voltage (V_CEsat) as low as −250 mV at I_C = −100 mA / I_B = −5 mA. Its f_T of 100 MHz supports audio-frequency amplification and fast digital switching up to ~10 MHz.

The device features low leakage: I_CBO ≤ −4 µA at T_j = 150 °C and I_EBO ≤ −100 nA, enabling stable operation in temperature-variable environments. Its 200 mW power dissipation limit and 150 °C max junction temperature are defined under standard FR4 PCB mounting conditions per IEC 60134.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	−45 V - Maximum allowable collector-emitter voltage before breakdown; defines safe operating range in low-voltage PNP switch configurations.
I_C	−100 mA - Continuous DC collector current rating; sets upper bound for load-driving capability in linear or saturated operation.
h_FE	420–800 at V_CE = −5 V, I_C = −2 mA - Guaranteed DC current gain band ensures predictable base drive requirements for reliable switching.
V_CEsat	−250 mV max at I_C = −100 mA, I_B = −5 mA - Low saturation voltage minimizes power loss and heating in high-duty-cycle switching applications.
R_th(j-a)	625 K/W - Junction-to-ambient thermal resistance on standard FR4 PCB; determines temperature rise under 200 mW dissipation.
f_T	100 MHz - Transition frequency confirms usable bandwidth for audio amplification and medium-speed digital signal inversion.
V_BE	−650 mV typical at V_CE = −5 V, I_C = −10 mA - Base-emitter forward voltage informs bias network design for stable quiescent point setting.

Pinout & Package

SOT323 (SC-70) plastic surface-mounted package: 1.35 mm × 1.75 mm footprint, 0.95 mm height, 3-lead single-row configuration with gull-wing terminations.

Pin/Terminal	Circuit Role	Design Meaning
1	Base (B)	Control terminal; requires current-limited drive to achieve target I_C; polarity-sensitive for PNP operation.
2	Emitter (E)	Current source terminal; connected to higher potential rail in common-emitter switch configurations.
3	Collector (C)	Current sink terminal; connects to load and lower-potential node; handles full switched current and voltage stress.

Key Features

Feature	Design Value
High h_FE grade (C)	420–800 gain band enables reduced base drive current and smaller bias resistors in amplifier/switch stages.
SOT323 ultra-small footprint	1.35 mm × 1.75 mm outline allows dense placement in space-constrained portable and wearable PCB layouts.
Low V_CEsat	≤ −250 mV at full rated current reduces conduction loss and self-heating in battery-powered load switches.
Specified thermal performance	625 K/W R_th(j-a) on FR4 enables accurate junction temperature estimation without derating assumptions.
Robust leakage control	I_CBO ≤ −4 µA at 150 °C ensures stable off-state behavior in thermally demanding industrial ambient conditions.

Applications

LED Driver Stage

Microcontroller Level Shifter

Use Scenario: Driving 20 mA indicator LEDs from 3.3 V microcontroller GPIO pins with inverted logic.

IC Role / Device Role / Timing Role: PNP switch providing active-low current sinking path with minimal base loading.

Use Value: Guaranteed h_FE ≥ 420 ensures <10 µA base current suffices for full LED current, preserving MCU drive strength.

Use Scenario: Translating 1.8 V logic-high signals to 5 V rail for legacy peripherals.

IC Role / Device Role / Timing Role: Discrete level translator using emitter-follower or common-emitter inverter topology.

Use Value: −45 V V_CEO and low V_CEsat support clean 5 V output swing with sub-µs propagation delay.

Audio Pre-amplifier Input Stage

Power Supply Enable Control

Use Scenario: Low-noise, low-current preamp stage for electret microphone biasing and signal buffering.

IC Role / Device Role / Timing Role: Common-emitter amplifier with fixed bias network and emitter degeneration.

Use Value: 2 dB noise figure at 1 kHz and 100 MHz f_T preserve signal integrity in 20 Hz–20 kHz audio band.

Use Scenario: Enabling/disabling 12 V auxiliary rails via microcontroller GPIO in embedded power management.

IC Role / Device Role / Timing Role: High-side PNP switch controlling PMOS gate or LDO enable input.

Use Value: −45 V rating safely accommodates 12 V rail transients; 200 mW P_tot allows continuous duty-cycle operation.

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	h_FE = 220–475; lower gain band than BC857CW	Suitable where tighter base-current tolerance is acceptable and cost optimization is prioritized	Select when gain consistency at low I_C (<1 mA) is less critical than unit cost
MMBT3906LT1G	V_CEO = −40 V; h_FE = 100–300; SOT23 package (larger footprint)	Compatible in non-footprint-constrained designs requiring broader vendor availability	Choose only if SOT23 layout space is available and −40 V rating meets system margin requirements

Compared with BC857BW and MMBT3906LT1G, BC857CW/DG/B4F delivers superior gain consistency for precision biasing and lower V_CEsat for efficiency-critical switching - justifying its use where SOT323 size and high h_FE are design-enabling.

Availability

BC857CW/DG/B4F is available at Aetrix Electronics and suitable for LED driver circuits, microcontroller interface logic, audio preamplifiers, and power rail enable controls requiring stable component supply across production volumes.

Supply support for BC857CW/DG/B4F 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 for automotive, industrial, mobile, and computing markets.

BC857CW belongs to Nexperia's BC856W/BC857W/BC858W family of general-purpose PNP transistors designed for compact, cost-effective switching and amplification in consumer and industrial electronics.

FAQ

What is the maximum junction temperature and thermal resistance of BC857CW/DG/B4F?

The absolute maximum junction temperature is 150 °C. Its thermal resistance from junction to ambient (R_th(j-a)) is 625 K/W when mounted on a standard FR4 PCB with single-sided 35 µm copper and tin-plated finish - measured under free-air conditions per IEC 60134.

Does BC857CW/DG/B4F have automotive qualification?

No. BC857CW/DG/B4F is not automotive-qualified. It is specified and tested for industrial and consumer applications only. Nexperia explicitly states that non-automotive qualified products are unsuitable for safety-critical, life-support, or automotive systems without additional customer validation.

How does the BC857CW h_FE grading differ from BC857AW and BC857BW?

BC857CW guarantees h_FE = 420–800 at V_CE = −5 V and I_C = −2 mA; BC857AW is 125–250; BC857BW is 220–475. The 'C' grade provides the highest and widest gain band, enabling more consistent performance across production lots in precision analog or low-base-drive digital applications.

Can BC857CW/DG/B4F replace BC857B in existing SOT323 designs?

Yes, electrically and mechanically - both share identical SOT323 package, pinout, and voltage/current ratings. However, BC857CW offers higher h_FE (420–800 vs. 220–475), which may reduce required base drive but could affect stability in some feedback circuits; verify bias point and transient response in the target application.

BC857CW/DG/B4F 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:: 420 @ 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

BC857CW/DG/B4F FAQ

1.How can I place an order for BC857CW/DG/B4F through Aetrix?

Please submit a Request for Quotation (RFQ) for BC857CW/DG/B4F 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 BC857CW/DG/B4F reliable?

The price and inventory of BC857CW/DG/B4F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC857CW/DG/B4F is usually 5 days.

3.What payment methods are accepted for BC857CW/DG/B4F?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC857CW/DG/B4F transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BC857CW/DG/B4F?

BC857CW/DG/B4F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BC857CW/DG/B4F 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 BC857CW/DG/B4F?

For technical support, including BC857CW/DG/B4F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC857CW/DG/B4F requirements.

6.How does Aetrix verify that BC857CW/DG/B4F is sourced from the original manufacturer or authorized distributors?

All BC857CW/DG/B4F 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 BC857CW/DG/B4F meets industry standards.

7.What is the process for return or replacement of BC857CW/DG/B4F?

All BC857CW/DG/B4F units undergo pre-shipment inspection (PSI). If there is an issue with BC857CW/DG/B4F, 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 BC857CW/DG/B4F part is unused and in its original packaging.

Return procedure for BC857CW/DG/B4F:

1.Submit a request within 90 days.

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

Tech Hub

2026-09-03 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-01 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…

2026-08-21 What Is an LED Driver? Types, Circuits, Dimming, and Selection

An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…

2026-08-18 Operational Amplifier (Op Amp): Basics, Configurations, Feedback and Applications

Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…

2026-08-14 Jumper Cables: How to Use, Connect and Choose Them Safely

Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…