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

onsemi BC858AWT1

Name: BC858AWT1
Brand: onsemi
SKU: BC858AWT1
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: BC858AWT1

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: SC-70, SOT-323

Datasheet:: BC858AWT1.pdf

Description:: TRANS PNP 30V 0.1A SC70-3

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:9,297

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

Product details

Overview

BC858AWT1 from onsemi is a PNP silicon general-purpose transistor in SC-70/SOT-323 package, rated for −30 V V_CEO, −100 mA I_C, and 150 mW power dissipation, optimized for low-power amplifier and switching applications in portable and space-constrained designs.

For engineers reviewing the BC858AWT1 datasheet, pinout, applications, or equivalent options, this page delivers verified electrical specs, thermal limits, saturation behavior, small-signal bandwidth (f_T = 100 MHz), and real-world use context for signal conditioning, level shifting, and discrete logic interface circuits.

Technical Context

The BC858AWT1 operates as a single PNP bipolar junction transistor with fixed emitter-base and collector-base junction structures, supporting linear amplification and saturated switching modes. Its DC current gain (h_FE) ranges from 125 to 250 at I_C = −10 mA and V_CE = −5.0 V, and its f_T of 100 MHz enables audio-frequency and low-speed digital signal handling.

Thermal performance is defined by R_JA = 883°C/W on FR-5 board and T_J range of −55°C to +150°C. Safe operating area (SOA) curves confirm reliability under pulsed loads up to 3 ms, with secondary breakdown and thermal limits explicitly plotted for design margining.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	−30 V - Maximum allowable collector-emitter voltage before breakdown; sets upper rail limit in PNP switch or amplifier stages.
I_C (max)	−100 mA - Continuous collector current rating; defines maximum load drive capability in active or saturated operation.
P_D	150 mW - Total device dissipation on FR-5 board at 25°C; constrains power budget in thermally unmanaged PCB layouts.
h_FE	125–250 - DC current gain range at I_C = −10 mA/V_CE = −5 V; determines base drive requirements for predictable switching or amplification.
f_T	100 MHz - Current-gain bandwidth product; supports stable small-signal amplification up to ~10 MHz with gain >10.
V_CE(sat)	−0.3 V (typ.) at I_C = −10 mA/I_B = −0.5 mA - Low saturation voltage minimizes conduction loss in high-efficiency PNP switches.
C_ob	4.5 pF - Output capacitance at V_CB = −10 V; impacts high-frequency response and stability in RF-adjacent or fast-switching nodes.

Pinout & Package

BC858AWT1 is housed in the SC-70/SOT-323 surface-mount package (Case 419, Style 3), measuring 2.1 × 1.24 × 0.9 mm, with gull-wing leads optimized for automated placement and reflow soldering on dense PCBs.

Pin/Terminal	Circuit Role	Design Meaning
1	Base	Control terminal for forward-biased PNP operation; requires negative bias relative to emitter to enable conduction.
2	Emitter	Current source terminal in PNP configuration; typically tied to higher potential (e.g., V_CC) in common-emitter amplifiers or switches.
3	Collector	Current sink terminal; connects to load or next stage; reverse polarity relative to NPN counterparts dictates layout orientation.

Key Features

Feature	Design Value
Pb-free packaging	RoHS-compliant SC-70 construction with lead-free terminations, qualified for standard reflow profiles without SnPb compatibility concerns.
Low V_CE(sat)	Typical −0.3 V enables <100 mW conduction loss at 100 mA, improving efficiency in battery-powered PNP load switches.
High f_T	100 MHz bandwidth supports clean amplification of audio signals and reliable edge integrity in ≤10 MHz digital interfaces.
Wide T_J range	−55°C to +150°C junction temperature rating allows deployment in automotive under-hood, industrial control, and outdoor electronics.
Controlled h_FE spread	125–250 gain range ensures predictable base resistor selection across production lots without iterative tuning.

Applications

Audio Pre-amplifier Stage	Level-Shifting Interface
Use Scenario: Amplifying weak microphone or sensor signals in portable audio devices before ADC sampling. IC Role / Device Role / Timing Role: Discrete PNP common-emitter amplifier providing 20–50× voltage gain with low noise (NF = 10 dB). Use Value: Delivers stable mid-band gain with minimal distortion due to controlled h_FE and low C_ob, avoiding high-frequency roll-off in 20 Hz–20 kHz band.	Use Scenario: Translating logic-level signals between 5 V microcontroller outputs and 3.3 V or 1.8 V peripheral inputs. IC Role / Device Role / Timing Role: Active PNP level shifter enabling bidirectional or unidirectional voltage translation with sub-10 ns propagation delay. Use Value: Achieves rail-to-rail swing with <0.3 V saturation drop, preserving noise margins and timing integrity across mixed-voltage domains.
LED Driver Switch	Discrete Logic Inverter
Use Scenario: Driving indicator LEDs or low-current status lamps from GPIO pins in wearables and IoT endpoints. IC Role / Device Role / Timing Role: Saturated PNP switch sinking current from V_CC through LED cathode to ground-referenced load. Use Value: Enables <10 µA standby leakage and <0.3 V dropout at 20 mA, maximizing LED brightness and battery runtime.	Use Scenario: Implementing non-inverting or inverting logic functions where gate ICs are unavailable or overkill. IC Role / Device Role / Timing Role: Configured as common-emitter inverter or emitter-follower buffer for signal polarity reversal or impedance matching. Use Value: Provides deterministic logic thresholds and fan-out ≥5 due to h_FE ≥125, supporting robust discrete glue logic in legacy or ultra-low-cost systems.

Audio Pre-amplifier Stage

Level-Shifting Interface

Use Scenario: Amplifying weak microphone or sensor signals in portable audio devices before ADC sampling.

IC Role / Device Role / Timing Role: Discrete PNP common-emitter amplifier providing 20–50× voltage gain with low noise (NF = 10 dB).

Use Value: Delivers stable mid-band gain with minimal distortion due to controlled h_FE and low C_ob, avoiding high-frequency roll-off in 20 Hz–20 kHz band.

Use Scenario: Translating logic-level signals between 5 V microcontroller outputs and 3.3 V or 1.8 V peripheral inputs.

IC Role / Device Role / Timing Role: Active PNP level shifter enabling bidirectional or unidirectional voltage translation with sub-10 ns propagation delay.

Use Value: Achieves rail-to-rail swing with <0.3 V saturation drop, preserving noise margins and timing integrity across mixed-voltage domains.

LED Driver Switch

Discrete Logic Inverter

Use Scenario: Driving indicator LEDs or low-current status lamps from GPIO pins in wearables and IoT endpoints.

IC Role / Device Role / Timing Role: Saturated PNP switch sinking current from V_CC through LED cathode to ground-referenced load.

Use Value: Enables <10 µA standby leakage and <0.3 V dropout at 20 mA, maximizing LED brightness and battery runtime.

Use Scenario: Implementing non-inverting or inverting logic functions where gate ICs are unavailable or overkill.

IC Role / Device Role / Timing Role: Configured as common-emitter inverter or emitter-follower buffer for signal polarity reversal or impedance matching.

Use Value: Provides deterministic logic thresholds and fan-out ≥5 due to h_FE ≥125, supporting robust discrete glue logic in legacy or ultra-low-cost systems.

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
BC857BWT1	V_CEO = −45 V, V_CBO = −50 V, h_FE = 220–475 - higher voltage rating and wider gain range than BC858AWT1.	Better suited for 5–12 V supply rails requiring extra breakdown margin; less optimal where strict −30 V compliance is required.	Select BC857BWT1 when higher V_CEO headroom is needed without changing footprint or bias network.
BC858BWT1	Same package and pinout; h_FE = 150–290 - tighter gain distribution and slightly higher minimum h_FE than BC858AWT1's 125–250.	Preferred for designs requiring more consistent base drive across temperature and process variation.	Choose BC858BWT1 when gain predictability and reduced base resistor tolerance sensitivity are critical.

Compared with BC857BWT1 and BC858BWT1, the BC858AWT1 offers the lowest V_CEO rating but remains optimal for cost-sensitive 3.3 V/5 V systems where precise −30 V compliance and moderate gain consistency are prioritized over extended voltage margin or tighter h_FE spread.

Availability

BC858AWT1 is available at Aetrix Electronics and suitable for portable audio pre-amplifiers, mixed-voltage logic interfaces, LED driver circuits, and discrete signal conditioning modules requiring stable component supply and long-term obsolescence management.

Supply support for BC858AWT1 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 focused on energy-efficient innovation, delivering power management, analog, sensing, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.

The BC858AWT1 belongs to onsemi's general-purpose bipolar transistor family designed for cost-effective, space-efficient amplification and switching in consumer, computing, and industrial electronics where reliability and manufacturability are essential.

FAQ

What is the maximum collector-emitter voltage rating for BC858AWT1?

The BC858AWT1 has a maximum collector-emitter voltage (V_CEO) rating of −30 V at T_A = 25°C. This value is absolute maximum and must not be exceeded in operation; derating is required at elevated temperatures per the device's thermal characteristics. The BC858AWT1 datasheet confirms this rating applies specifically to the BC858 series, distinguishing it from BC856 (−65 V) and BC857 (−45 V) variants.

Is BC858AWT1 RoHS compliant and lead-free?

Yes, BC858AWT1 is RoHS compliant and offered in Pb-free packaging. The datasheet explicitly states "Pb−Free Packages are Available" and lists BC858AWT1G as the lead-free variant. The SC-70/SOT-323 package uses matte tin terminations qualified for standard lead-free reflow profiles, with no exemption required under current EU RoHS directives.

What is the typical DC current gain (h_FE) of BC858AWT1 at I_C = −10 mA?

The BC858AWT1 exhibits a typical DC current gain (h_FE) of 180 at I_C = −10 mA and V_CE = −5.0 V, with a guaranteed minimum of 125 and maximum of 250. This gain range is confirmed in the Electrical Characteristics table and supports predictable base resistor calculation for both switching and linear amplifier configurations using the BC858AWT1.

Can BC858AWT1 be used in audio-frequency amplifier circuits?

Yes, BC858AWT1 is suitable for audio-frequency amplification due to its 100 MHz f_T, low noise figure (NF = 10 dB at 1 kHz), and stable h_FE across the 20 Hz–20 kHz band. Its low C_ob (4.5 pF) and controlled saturation behavior ensure minimal phase shift and harmonic distortion in pre-amplifier and driver stages using the BC858AWT1.

What is the thermal resistance from junction to ambient (R_JA) for BC858AWT1 on FR-5 board?

The thermal resistance from junction to ambient (R_JA) for BC858AWT1 is 883°C/W when mounted on an FR-5 board at T_A = 25°C, as specified in the Thermal Characteristics table. This value assumes standard 1.0 × 0.75 × 0.062 inch board dimensions and informs thermal design margining for continuous 150 mW operation using the BC858AWT1.

BC858AWT1 Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

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):: 30 V

Vce Saturation (Max) @ Ib, Ic:: 650mV @ 5mA, 100mA

Current - Collector Cutoff (Max):: 15nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 125 @ 2mA, 5V

Power - Max:: 150 mW

Frequency - Transition:: 100MHz

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SC-70-3 (SOT323)

BC858AWT1 FAQ

1.How can I place an order for BC858AWT1 through Aetrix?

Please submit a Request for Quotation (RFQ) for BC858AWT1 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 BC858AWT1 reliable?

The price and inventory of BC858AWT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC858AWT1 is usually 5 days.

3.What payment methods are accepted for BC858AWT1?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC858AWT1 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BC858AWT1?

BC858AWT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BC858AWT1 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 BC858AWT1?

For technical support, including BC858AWT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC858AWT1 requirements.

6.How does Aetrix verify that BC858AWT1 is sourced from the original manufacturer or authorized distributors?

All BC858AWT1 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 BC858AWT1 meets industry standards.

7.What is the process for return or replacement of BC858AWT1?

All BC858AWT1 units undergo pre-shipment inspection (PSI). If there is an issue with BC858AWT1, 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 BC858AWT1 part is unused and in its original packaging.

Return procedure for BC858AWT1:

1.Submit a request within 90 days.

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

Tech Hub

2026-09-09 Counterfeit Electronic Components: How to Detect, Authenticate, and Test Suspect Parts

Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …

2026-09-08 Obsolete Electronic Components: How to Source and Evaluate Replacements

A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 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…

2026-09-02 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…