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

onsemi BC858BLT1

Name: BC858BLT1
Brand: onsemi
SKU: BC858BLT1
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BC858BLT1

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: -

Datasheet:: BC858BLT1.pdf

Description:: TRANS PNP LP 100MA 30V SOT23

Quantity:: RFQ Add To RFQ list

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Product details

Overview

BC858BLT1 from onsemi is a PNP silicon general-purpose transistor in SOT-23 package, rated for V_CEO = −30 V, I_C = −100 mA continuous, h_FE = 220–475 (at I_C = −10 mA, V_CE = −5 V), V_CE(sat) ≤ −0.65 V (at I_C = −100 mA, I_B = −5 mA), and f_T = 100 MHz - used in low-voltage switching and amplification circuits in automotive body control modules.

For engineers reviewing the BC858BLT1 datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, thermal derating data, AEC-Q101 qualification status, SOT-23 terminal mapping, and two validated alternative transistors for design-in flexibility.

Technical Context

The BC858BLT1 operates as a discrete PNP bipolar junction transistor with fixed emitter-base and collector-base junctions optimized for linear amplification and saturated switching. Its DC current gain (h_FE) exhibits strong dependence on collector current and temperature, with typical values of 220 at −10 mA and up to 475 at −2 mA, enabling stable biasing in Class-A amplifier stages.

It features low saturation voltage (V_CE(sat) ≤ −0.65 V) under high-current drive, fast switching performance (t_d = 35 ns, t_r = 25 ns), and low output capacitance (C_ob = 4.5 pF), supporting reliable operation in 100 kHz–1 MHz signal routing and PWM-driven load control.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	−30 V - Maximum allowable collector-emitter voltage before breakdown; defines safe operating range in 24 V automotive supply rails.
I_C (continuous)	−100 mA - Continuous collector current rating; supports driving small relays, LEDs, or logic-level interface loads without heatsinking.
h_FE	220–475 - DC current gain range at I_C = −10 mA / −2 mA; enables predictable base drive sizing for stable switching thresholds.
V_CE(sat)	≤ −0.65 V @ I_C = −100 mA - Low saturation voltage minimizes power loss and self-heating during on-state operation.
f_T	100 MHz - Current-gain bandwidth product; confirms suitability for audio-frequency amplification and fast digital switching up to ~10 MHz.
R_JA	556 °C/W (FR-5 board) - Thermal resistance determines maximum power dissipation (225 mW @ 25°C) and required ambient derating.
AEC-Q101	Qualified - Certified for automotive applications including engine control units, lighting drivers, and HVAC actuators.

Pinout & Package

SOT-23 (TO-236) surface-mount plastic package, 2.90 × 1.30 × 1.00 mm, 3-pin configuration with gull-wing leads. RoHS-compliant, Pb-free, halogen-free/BFR-free construction.

Pin/Terminal	Circuit Role	Design Meaning
1	Base	Control terminal; requires current-limited drive (typically 1–5% of I_C) to achieve full saturation or linear operation.
2	Emitter	Common reference node; connected to higher potential (e.g., +12 V rail) in PNP switch configurations.
3	Collector	Output terminal; sinks current to ground or lower-potential node when biased on; handles full load current path.

Key Features

Feature	Design Value
AEC-Q101 qualified	Validated for automotive-grade reliability across −40°C to +150°C junction temperature range.
Low V_CE(sat)	≤ −0.65 V ensures <150 mW conduction loss at 100 mA, reducing thermal stress in space-constrained PCB layouts.
High h_FE bin (B grade)	220–475 gain range allows simplified base resistor selection and tighter tolerance on switching timing.
Fast switching	35 ns delay + 25 ns rise time enables clean edge transitions in 1–5 MHz clocked logic interfaces and PWM dimming.
Low C_ob	4.5 pF output capacitance minimizes high-frequency signal loading and improves stability in RF-adjacent analog stages.

Applications

Automotive Interior Lighting Control	Industrial Sensor Signal Conditioning
Use Scenario: Driving 12 V LED strings in door courtesy lights and map lamps using PWM from microcontroller GPIO. IC Role / Device Role / Timing Role: PNP switch controlling current sink path to ground; acts as level-shifting high-side driver. Use Value: Low V_CE(sat) reduces heat generation in sealed lamp housings; AEC-Q101 qualification ensures 15-year field reliability.	Use Scenario: Amplifying low-level thermistor or RTD bridge outputs in programmable logic controller (PLC) analog input modules. IC Role / Device Role / Timing Role: Linear amplifier stage providing 10–100× gain with minimal offset drift over −25°C to +70°C. Use Value: Stable h_FE and low noise figure (NF = 10 dB) preserve signal integrity in 200 Hz bandwidth measurement channels.
Consumer Appliance Power Sequencing	Medical Diagnostic Equipment Biasing
Use Scenario: Enabling/disabling 5 V auxiliary rails in smart washing machine control boards based on MCU wake-up signals. IC Role / Device Role / Timing Role: General-purpose switch sequencing power to isolated subsystems (e.g., display, motor driver ICs). Use Value: Fast turn-on/turn-off times prevent voltage overshoot during rail ramp-up; SOT-23 footprint saves board area in multi-rail PMIC designs.	Use Scenario: Providing precise bias current to op-amp input stages in portable ECG front-end amplifiers. IC Role / Device Role / Timing Role: Current source element establishing stable quiescent operating point for ultra-low-noise instrumentation amplifiers. Use Value: Tight h_FE binning and low V_BE(on) variation (−0.6 to −0.82 V) ensure consistent bias current across production lots.

Automotive Interior Lighting Control

Industrial Sensor Signal Conditioning

Use Scenario: Driving 12 V LED strings in door courtesy lights and map lamps using PWM from microcontroller GPIO.

IC Role / Device Role / Timing Role: PNP switch controlling current sink path to ground; acts as level-shifting high-side driver.

Use Value: Low V_CE(sat) reduces heat generation in sealed lamp housings; AEC-Q101 qualification ensures 15-year field reliability.

Use Scenario: Amplifying low-level thermistor or RTD bridge outputs in programmable logic controller (PLC) analog input modules.

IC Role / Device Role / Timing Role: Linear amplifier stage providing 10–100× gain with minimal offset drift over −25°C to +70°C.

Use Value: Stable h_FE and low noise figure (NF = 10 dB) preserve signal integrity in 200 Hz bandwidth measurement channels.

Consumer Appliance Power Sequencing

Medical Diagnostic Equipment Biasing

Use Scenario: Enabling/disabling 5 V auxiliary rails in smart washing machine control boards based on MCU wake-up signals.

IC Role / Device Role / Timing Role: General-purpose switch sequencing power to isolated subsystems (e.g., display, motor driver ICs).

Use Value: Fast turn-on/turn-off times prevent voltage overshoot during rail ramp-up; SOT-23 footprint saves board area in multi-rail PMIC designs.

Use Scenario: Providing precise bias current to op-amp input stages in portable ECG front-end amplifiers.

IC Role / Device Role / Timing Role: Current source element establishing stable quiescent operating point for ultra-low-noise instrumentation amplifiers.

Use Value: Tight h_FE binning and low V_BE(on) variation (−0.6 to −0.82 V) ensure consistent bias current across production lots.

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
BC858CLT1G	Higher h_FE bin (420–800); same V_CEO, I_C, package, and AEC-Q101 qualification.	Preferred where tighter gain tolerance or lower base drive current is needed (e.g., battery-powered sensor nodes).	Select BC858CLT1G when designing for ultra-low base current consumption or improved loop gain margin in feedback circuits.
MMBT3906LT1G	Same V_CEO (−40 V), slightly higher I_C (−200 mA), h_FE = 100–300, non-AEC-Q101; identical SOT-23 pinout.	Used in commercial-grade industrial controls where automotive qualification is not mandated.	Choose MMBT3906LT1G for cost-sensitive non-automotive applications requiring higher peak current capability.

Compared with BC858BLT1, BC858CLT1G offers higher gain for reduced base drive burden but no improvement in voltage or thermal specs, while MMBT3906LT1G trades AEC-Q101 compliance for higher current rating and broader commercial availability - both require no PCB layout changes due to identical SOT-23 footprint and pin assignment.

Availability

BC858BLT1 is available at Aetrix Electronics and suitable for automotive lighting control, industrial sensor interfaces, and consumer appliance power sequencing requiring stable component supply, long-term lifecycle support, and AEC-Q101 traceability.

Supply support for BC858BLT1 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 is a global semiconductor supplier specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and IoT markets.

The BC858BLT1 belongs to onsemi's BC856ALT1G Series of automotive-qualified PNP transistors, designed specifically for robust, high-reliability switching and amplification in harsh-environment electronic control units.

FAQ

What is the maximum junction temperature rating for BC858BLT1?

The BC858BLT1 has a specified junction and storage temperature range of −55°C to +150°C. This rating is confirmed in the Thermal Characteristics section of the official onsemi datasheet (Rev. 17, April 2023). Operation beyond +150°C risks permanent degradation of h_FE and increased leakage current. Derating must follow the 1.8 mW/°C rule above 25°C ambient on FR-5 board.

Is BC858BLT1 pin-compatible with BC857BLT1G?

Yes, BC858BLT1 is pin-compatible with BC857BLT1G - both use SOT-23 package with identical pin 1 (Base), pin 2 (Emitter), pin 3 (Collector) assignment per onsemi's CASE 318 STYLE 6 mechanical drawing. However, BC857BLT1G has V_CEO = −45 V and V_CBO = −50 V, making it unsuitable as a direct replacement in −30 V–rated circuits without redesign verification.

Does BC858BLT1 meet AEC-Q101 requirements?

Yes, BC858BLT1 meets AEC-Q101 qualification standards, as explicitly stated in the "Features" section of the onsemi BC856ALT1G Series datasheet: "S and NSV Prefix for Automotive and Other Applications Requiring Unique Site and Control Change Requirements; AEC−Q101 Qualified and PPAP Capable." The NSV prefix in the ordering row NSVBC858BLT1G* confirms its automotive-grade status.

What is the typical noise figure of BC858BLT1 at 1 kHz?

The BC858BLT1 has a noise figure of 10 dB at I_C = −0.2 mA, V_CE = −5.0 V, R_S = 2.0 kΩ, and 200 Hz bandwidth, as published in the Electrical Characteristics table on page 2 of the onsemi datasheet. This value applies to the entire BC856/BC857/BC858/NSVBC858 series and is measured under standardized low-signal conditions relevant to sensor preamplifier design.

Can BC858BLT1 be used in linear amplifier configurations?

Yes, BC858BLT1 is suitable for linear amplifier use, supported by its specified h_FE linearity (Figure 1), V_BE(on) consistency (−0.6 to −0.82 V), and low distortion characteristics shown in the active region SOA curve (Figure 14). Designers should bias within the −2 mA to −10 mA I_C range and maintain V_CE > −5 V to avoid saturation and ensure gain stability per the datasheet's ON CHARACTERISTICS section.

BC858BLT1 Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: -

Packaging:: Bulk

Product Status:: Obsolete

Transistor Type:: -

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

Voltage - Collector Emitter Breakdown (Max):: -

Vce Saturation (Max) @ Ib, Ic:: -

Current - Collector Cutoff (Max):: -

DC Current Gain (hFE) (Min) @ Ic, Vce:: -

Power - Max:: -

Frequency - Transition:: -

Operating Temperature:: -

Grade:: -

Qualification:: -

Mounting Type:: -

Supplier Device Package:: -

BC858BLT1 FAQ

1.How can I place an order for BC858BLT1 through Aetrix?

Please submit a Request for Quotation (RFQ) for BC858BLT1 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 BC858BLT1 reliable?

The price and inventory of BC858BLT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC858BLT1 is usually 5 days.

3.What payment methods are accepted for BC858BLT1?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC858BLT1 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BC858BLT1?

BC858BLT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BC858BLT1 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 BC858BLT1?

For technical support, including BC858BLT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC858BLT1 requirements.

6.How does Aetrix verify that BC858BLT1 is sourced from the original manufacturer or authorized distributors?

All BC858BLT1 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 BC858BLT1 meets industry standards.

7.What is the process for return or replacement of BC858BLT1?

All BC858BLT1 units undergo pre-shipment inspection (PSI). If there is an issue with BC858BLT1, 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 BC858BLT1 part is unused and in its original packaging.

Return procedure for BC858BLT1:

1.Submit a request within 90 days.

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

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