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

onsemi BC859BLT3G

Name: BC859BLT3G
Brand: onsemi
SKU: BC859BLT3G
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BC859BLT3G

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-236-3, SC-59, SOT-23-3

Datasheet:: BC859BLT3G.pdf

Description:: TRANS PNP 30V 0.1A SOT23-3

Quantity:: RFQ Add To RFQ list

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Product details

Overview

BC859BLT3G from onsemi is a PNP silicon general-purpose transistor in SOT-23 package, rated for −30 V V_CEO, −100 mA I_C continuous, 225 mW power dissipation on FR-5 board, with h_FE = 220–520 (at I_C = −10 mA, V_CE = −5.0 V), and f_T = 100 MHz - used in low-voltage switching and linear amplification circuits in consumer and industrial power management.

For engineers reviewing the BC859BLT3G datasheet, pinout, applications, or equivalent options, key selection criteria include its PNP polarity, SOT-23 footprint compatibility, −30 V breakdown rating, DC current gain range, and thermal performance on standard PCB substrates.

Technical Context

This device operates as a discrete bipolar junction transistor with fixed PNP polarity, designed for general-purpose amplification and switching where moderate voltage handling and predictable DC gain are required. Its electrical behavior is defined by V_CEO = −30 V, V_CBO = −30 V, and V_EBO = −5.0 V - limiting usable bias ranges in emitter-follower or common-emitter configurations.

Thermal design relies on R_JA = 556 °C/W (FR-5) or 417 °C/W (alumina), with derating of 1.8 mW/°C above 25°C on FR-5 board. Switching performance is characterized by t_d = 35 ns, t_r = 25 ns, t_s = 310 ns, and t_f = 40 ns under −3.0 V V_CC, −10 mA I_C conditions - indicating suitability for medium-speed digital logic interfacing.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	−30 V - Maximum collector-emitter voltage before breakdown; defines safe operating voltage headroom in PNP switch or amplifier stages.
I_C (cont.)	−100 mA - Continuous collector current limit; sets maximum load drive capability without thermal runaway on standard FR-5 PCB.
h_FE	220–520 at I_C = −10 mA, V_CE = −5.0 V - DC current gain range determines base drive requirements and signal amplification stability.
f_T	100 MHz - Current-gain bandwidth product; indicates usable small-signal amplification up to ~10 MHz with gain >10.
P_D (FR-5)	225 mW at T_A = 25°C - Total power dissipation limit on standard epoxy-glass board; requires thermal derating above ambient.
C_ob	4.5 pF at V_CB = −10 V - Output capacitance affects high-frequency response and switching speed in tuned or fast-switching circuits.
NF	4.0 dB at I_C = −0.2 mA, V_CE = −5.0 V - Noise figure specifies low-noise amplification capability in audio or sensor front-end applications.

Pinout & Package

SOT-23 (TO-236) surface-mount package, 2.90 × 1.30 × 1.00 mm, 3-pin configuration per Style 6 mechanical outline.

Pin/Terminal	Circuit Role	Design Meaning
1	Base	Control terminal for forward-biased PNP operation; requires negative base current relative to emitter to turn on.
2	Emitter	Current source terminal in PNP configuration; connected to higher potential (e.g., V_CC) in common-emitter switches.
3	Collector	Current sink terminal; output node for amplified or switched current flow toward lower-potential load or ground.

Key Features

Feature	Design Value
Pb-free, Halogen-free, RoHS-compliant	Meets environmental compliance standards for industrial and consumer PCB assembly without lead-based solder restrictions.
AEC-Q101 qualified (S/NSV variants)	Qualified for automotive-grade reliability; BC859BLT3G itself is not marked S/NSV but shares same die and process as qualified family.
Low saturation voltage	V_CE(sat) = −0.3 V at I_C = −10 mA, I_B = −0.5 mA - minimizes conduction loss in saturated switching applications.
High f_T / low C_ob combination	100 MHz f_T with only 4.5 pF C_ob enables stable RF amplification up to UHF band in low-power stages.
Wide temperature range	Operable from −55°C to +150°C - supports deployment in under-hood automotive, industrial control, and outdoor electronics.

Applications

LED Driver Circuit	Level-Shifting Interface
Use Scenario: Driving 20 mA indicator LEDs from 3.3 V or 5 V microcontroller GPIO pins with active-low control. IC Role / Device Role: PNP switch configured in common-emitter mode, sinking current from LED anode to ground when base is pulled low. Use Value: Low V_CE(sat) (−0.3 V) ensures >95% LED forward voltage utilization; h_FE ≥ 220 allows <50 µA base drive for full LED brightness.	Use Scenario: Translating 1.8 V logic outputs to 5 V or 12 V domains in mixed-voltage systems. IC Role / Device Role: PNP level shifter with emitter tied to high-side rail, collector driving load, base controlled via resistor divider. Use Value: −30 V V_CEO supports up to 12 V rail translation; fast switching (t_r/t_f ≤ 40 ns) maintains signal integrity up to 10 Mbps.
Audio Pre-amplifier Stage	Power Supply Enable Switch
Use Scenario: Low-noise voltage amplification of microphone or sensor signals in battery-powered audio devices. IC Role / Device Role: Common-emitter amplifier biased in linear region with emitter degeneration for gain stability. Use Value: 4.0 dB noise figure at 1 kHz and low I_C operation enable clean signal amplification; h_FE consistency reduces gain drift across units.	Use Scenario: Enabling/disabling 5 V or 12 V subsystems (e.g., sensors, radios) using microcontroller GPIO. IC Role / Device Role: High-side PNP pass switch controlling power delivery to downstream circuitry. Use Value: −100 mA I_C rating supports typical subsystem loads; −30 V rating accommodates input transients; SOT-23 footprint saves board space.

LED Driver Circuit

Level-Shifting Interface

Use Scenario: Driving 20 mA indicator LEDs from 3.3 V or 5 V microcontroller GPIO pins with active-low control.

IC Role / Device Role: PNP switch configured in common-emitter mode, sinking current from LED anode to ground when base is pulled low.

Use Value: Low V_CE(sat) (−0.3 V) ensures >95% LED forward voltage utilization; h_FE ≥ 220 allows <50 µA base drive for full LED brightness.

Use Scenario: Translating 1.8 V logic outputs to 5 V or 12 V domains in mixed-voltage systems.

IC Role / Device Role: PNP level shifter with emitter tied to high-side rail, collector driving load, base controlled via resistor divider.

Use Value: −30 V V_CEO supports up to 12 V rail translation; fast switching (t_r/t_f ≤ 40 ns) maintains signal integrity up to 10 Mbps.

Audio Pre-amplifier Stage

Power Supply Enable Switch

Use Scenario: Low-noise voltage amplification of microphone or sensor signals in battery-powered audio devices.

IC Role / Device Role: Common-emitter amplifier biased in linear region with emitter degeneration for gain stability.

Use Value: 4.0 dB noise figure at 1 kHz and low I_C operation enable clean signal amplification; h_FE consistency reduces gain drift across units.

Use Scenario: Enabling/disabling 5 V or 12 V subsystems (e.g., sensors, radios) using microcontroller GPIO.

IC Role / Device Role: High-side PNP pass switch controlling power delivery to downstream circuitry.

Use Value: −100 mA I_C rating supports typical subsystem loads; −30 V rating accommodates input transients; SOT-23 footprint saves board space.

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
BC857BLT3G	V_CEO = −45 V, V_CBO = −50 V, h_FE = 220–520 (same bin), f_T = 100 MHz	Higher voltage rating suits 24 V industrial control; identical pinout and gain range.	Select BC857BLT3G when system supply exceeds 30 V or transient immunity >30 V is required.
BC858BLT3G	V_CEO = −30 V (same), V_CBO = −30 V (same), h_FE = 220–520 (same), f_T = 100 MHz (same)	Identical ratings and performance; differs only in internal die variant - functionally interchangeable.	BC858BLT3G offers same electrical specs and SOT-23 footprint; suitable for second-source procurement without redesign.

Compared with BC859BLT3G, BC857BLT3G provides higher voltage margin while maintaining identical gain and speed; BC858BLT3G delivers identical specifications and is fully substitutable in all designs using BC859BLT3G, enabling supply chain flexibility without layout or firmware changes.

Availability

BC859BLT3G is available at Aetrix Electronics and suitable for LED driver circuits, level-shifting interfaces, audio pre-amplifiers, and power supply enable switches requiring stable component supply, consistent parametric performance, and RoHS-compliant packaging.

Supply support for BC859BLT3G 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The BC859BLT3G belongs to the BC856ALT1G Series of general-purpose PNP transistors, designed for cost-sensitive, space-constrained applications requiring reliable switching and amplification across wide temperature and voltage ranges.

FAQ

What is the maximum collector-emitter voltage rating for BC859BLT3G?

The BC859BLT3G has a maximum collector-emitter voltage (V_CEO) rating of −30 V at T_A = 25°C. This rating defines the highest reverse-biased voltage that can be safely applied between collector and emitter before breakdown occurs. Exceeding this value risks permanent device failure, especially under elevated temperature or transient conditions.

Does BC859BLT3G support automotive applications?

BC859BLT3G itself is not marked with S or NSV prefix and is not individually AEC-Q101 certified; however, it shares the same die, process, and qualification data as the SBC859BLT3G and NSVBC859BLT3G variants, which are AEC-Q101 qualified and PPAP capable. For automotive use, engineers should specify the S- or NSV-prefixed version.

What is the DC current gain (h_FE) range of BC859BLT3G at typical operating conditions?

The BC859BLT3G exhibits h_FE = 220–520 when tested at I_C = −10 mA and V_CE = −5.0 V. This range reflects the B-grade binning for the BC859 series and ensures predictable base drive requirements in both switching and linear amplifier designs across production lots.

What package type and pin configuration does BC859BLT3G use?

BC859BLT3G uses the SOT-23 (TO-236) surface-mount package with Style 6 pinout: Pin 1 = Base, Pin 2 = Emitter, Pin 3 = Collector. Its dimensions are 2.90 × 1.30 × 1.00 mm, and it is supplied in 10,000-unit tape-and-reel format per the ordering code BLT3G.

How does BC859BLT3G perform thermally on a standard FR-5 PCB?

On FR-5 board, BC859BLT3G has a thermal resistance R_JA of 556 °C/W and a maximum power dissipation (P_D) of 225 mW at T_A = 25°C, derating by 1.8 mW/°C above that temperature. This means at 75°C ambient, usable power drops to ~135 mW - critical for sustained switching or linear operation in enclosed environments.

BC859BLT3G Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-236-3, SC-59, SOT-23-3

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Transistor Type:: PNP

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

Voltage - Collector Emitter Breakdown (Max):: 30 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:: 300 mW

Frequency - Transition:: 100MHz

Operating Temperature:: -55°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-3 (TO-236)

BC859BLT3G FAQ

1.How can I place an order for BC859BLT3G through Aetrix?

Please submit a Request for Quotation (RFQ) for BC859BLT3G 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 BC859BLT3G reliable?

The price and inventory of BC859BLT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC859BLT3G is usually 5 days.

3.What payment methods are accepted for BC859BLT3G?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC859BLT3G transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BC859BLT3G?

BC859BLT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BC859BLT3G 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 BC859BLT3G?

For technical support, including BC859BLT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC859BLT3G requirements.

6.How does Aetrix verify that BC859BLT3G is sourced from the original manufacturer or authorized distributors?

All BC859BLT3G 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 BC859BLT3G meets industry standards.

7.What is the process for return or replacement of BC859BLT3G?

All BC859BLT3G units undergo pre-shipment inspection (PSI). If there is an issue with BC859BLT3G, 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 BC859BLT3G part is unused and in its original packaging.

Return procedure for BC859BLT3G:

1.Submit a request within 90 days.

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

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