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 BC547ARL1G

Name: BC547ARL1G
Brand: onsemi
SKU: BC547ARL1G
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: BC547ARL1G

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-226-3, TO-92-3 Long Body, Formed Leads

Datasheet:: BC547ARL1G.pdf

Description:: TRANS NPN 45V 0.1A TO92

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:4,086

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

Product details

Overview

BC547ARL1G from onsemi is an NPN silicon general-purpose amplifier transistor in TO-92 package, rated for V_CEO = 45 V, I_C = 100 mA, and h_FE = 110–220 (at I_C = 2 mA), commonly used in low-power linear amplification and switching circuits in consumer electronics and industrial signal conditioning.

For engineers reviewing the BC547ARL1G datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, thermal behavior, junction temperature limits, saturation voltage performance, and real-world use context - all confirmed against onsemi's official BC546/D Rev. 5 datasheet.

Technical Context

The BC547ARL1G operates as a discrete bipolar junction transistor with fixed NPN polarity and DC current gain specified across three test conditions: h_FE = 110–220 at I_C = 2 mA, 110–290 at I_C = 10 mA, and 120–300 at I_C = 100 mA. Its f_T = 150–300 MHz supports audio-frequency amplification and low-speed switching.

Thermal design is constrained by R_JA = 200°C/W (ambient) and R_JC = 83.3°C/W (case), with T_J rated from −55°C to +150°C. V_CE(sat) ≤ 0.25 V at I_C = 10 mA / I_B = 0.5 mA ensures low-loss switching in driver stages.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	45 V - Maximum collector-emitter voltage before breakdown; defines safe operating range in common-emitter amplifier configurations.
I_C (continuous)	100 mA - Continuous collector current limit; sets upper bound for load-driving capability in relay drivers or LED switches.
h_FE (min–max)	110–220 @ I_C = 2 mA - DC current gain spread affecting bias stability and stage gain predictability in linear amplifiers.
V_CE(sat)	≤ 0.25 V @ I_C = 10 mA, I_B = 0.5 mA - Low saturation voltage enables efficient switching with minimal power loss in digital logic interfaces.
f_T	150–300 MHz - Transition frequency determines usable bandwidth for small-signal amplification up to mid-audio frequencies.
R_JA	200°C/W - Junction-to-ambient thermal resistance; requires heatsinking or layout derating above ~312 mW at 25°C ambient.
T_J range	−55°C to +150°C - Wide junction temperature tolerance supports operation in automotive under-hood and industrial control environments.

Pinout & Package

BC547ARL1G uses the industry-standard TO-92 (Case 29, Style 17) plastic package with 3 leads: Collector (Pin 1), Base (Pin 2), Emitter (Pin 3), as marked on device body and confirmed in onsemi's BC546/D datasheet Figure 1.

Pin/Terminal	Circuit Role	Design Meaning
1	Collector	Main current output terminal; connects to load or next stage; voltage referenced to emitter/base in active/saturation modes.
2	Base	Control input; small current here modulates large collector current; requires appropriate biasing network for stable Q-point.
3	Emitter	Current return path; often grounded or tied to emitter resistor for DC feedback and thermal stabilization.

Key Features

Feature	Design Value
Pb-free (RoHS-compliant) packaging	Meets global environmental compliance requirements without sacrificing solderability or reliability in reflow processes.
High h_FE consistency across variants	BC547A grade guarantees h_FE ≥ 110 at I_C = 2 mA, enabling predictable biasing in production-grade analog circuits.
Low V_CE(sat) at moderate drive	0.25 V max at I_C/I_B = 20 ensures <1% voltage drop in saturated switch applications, improving efficiency in discrete logic buffers.
Wide operating temperature range	−55°C to +150°C junction rating supports deployment in unregulated enclosures and thermally demanding industrial subsystems.
TO-92 mechanical standardization	Compatible with legacy PCB footprints, automated insertion equipment, and hand-soldering workflows without adapter tooling.

Applications

Audio Pre-amplifier Stage	Microcontroller GPIO Driver
Use Scenario: Amplifying weak microphone or sensor signals prior to ADC sampling in portable audio recorders or IoT edge nodes. IC Role / Device Role / Timing Role: Discrete NPN transconductance amplifier configured in common-emitter topology with emitter degeneration. Use Value: h_FE ≥ 110 and f_T ≥ 150 MHz enable clean 20 Hz–20 kHz gain without phase shift or distortion in single-stage designs.	Use Scenario: Driving LEDs, relays, or small solenoids from 3.3 V or 5 V microcontroller outputs where current exceeds GPIO sink/source limits. IC Role / Device Role / Timing Role: Low-side switch with base driven directly from MCU pin through current-limiting resistor. Use Value: V_CE(sat) ≤ 0.25 V minimizes power dissipation and heat rise during sustained ON-state operation at 10–50 mA loads.
Linear Voltage Regulator Pass Element	Discrete Logic Level Shifter
Use Scenario: Acting as series pass transistor in adjustable LDO-like regulators using op-amp error amplifiers and Zener references. IC Role / Device Role / Timing Role: Current-controlled variable resistor in emitter-follower configuration to regulate output voltage. Use Value: V_CEO = 45 V and T_J(max) = +150°C allow safe operation with >12 V input-to-output differentials and ambient temperatures up to +85°C.	Use Scenario: Translating logic levels between 3.3 V microcontrollers and 5 V peripherals such as displays or sensors in mixed-voltage embedded systems. IC Role / Device Role / Timing Role: Common-emitter inverter with pull-up resistor on collector to translate high/low states bidirectionally. Use Value: Fast turn-on/off (f_T ≥ 150 MHz) and tight V_BE(on) = 0.55–0.77 V ensure reliable switching at >1 MHz data rates without timing skew.

Audio Pre-amplifier Stage

Microcontroller GPIO Driver

Use Scenario: Amplifying weak microphone or sensor signals prior to ADC sampling in portable audio recorders or IoT edge nodes.

IC Role / Device Role / Timing Role: Discrete NPN transconductance amplifier configured in common-emitter topology with emitter degeneration.

Use Value: h_FE ≥ 110 and f_T ≥ 150 MHz enable clean 20 Hz–20 kHz gain without phase shift or distortion in single-stage designs.

Use Scenario: Driving LEDs, relays, or small solenoids from 3.3 V or 5 V microcontroller outputs where current exceeds GPIO sink/source limits.

IC Role / Device Role / Timing Role: Low-side switch with base driven directly from MCU pin through current-limiting resistor.

Use Value: V_CE(sat) ≤ 0.25 V minimizes power dissipation and heat rise during sustained ON-state operation at 10–50 mA loads.

Linear Voltage Regulator Pass Element

Discrete Logic Level Shifter

Use Scenario: Acting as series pass transistor in adjustable LDO-like regulators using op-amp error amplifiers and Zener references.

IC Role / Device Role / Timing Role: Current-controlled variable resistor in emitter-follower configuration to regulate output voltage.

Use Value: V_CEO = 45 V and T_J(max) = +150°C allow safe operation with >12 V input-to-output differentials and ambient temperatures up to +85°C.

Use Scenario: Translating logic levels between 3.3 V microcontrollers and 5 V peripherals such as displays or sensors in mixed-voltage embedded systems.

IC Role / Device Role / Timing Role: Common-emitter inverter with pull-up resistor on collector to translate high/low states bidirectionally.

Use Value: Fast turn-on/off (f_T ≥ 150 MHz) and tight V_BE(on) = 0.55–0.77 V ensure reliable switching at >1 MHz data rates without timing skew.

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN general-purpose amplifier applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
BC547BRL1G	h_FE = 200–450 (vs. 110–220 for BC547ARL1G); same V_CEO, I_C, package, and Pb-free construction.	Higher gain improves bias stability in high-impedance amplifier stages but increases sensitivity to thermal drift.	Select BC547BRL1G when tighter gain matching or higher small-signal amplification is required; otherwise BC547ARL1G offers better predictability in production-biased circuits.
BC548CRL1G	V_CEO = 30 V (vs. 45 V); h_FE = 420–800; identical TO-92 package and Pb-free marking.	Lower breakdown voltage restricts use to ≤30 V supply rails; ultra-high h_FE suits low-base-drive applications like phototransistor amplifiers.	Choose BC548CRL1G only for low-voltage (<30 V), high-gain signal conditioning; BC547ARL1G remains preferred for general-purpose 45 V-rated designs.

Compared with BC547BRL1G and BC548CRL1G, the BC547ARL1G provides the most balanced trade-off of voltage rating, gain consistency, and thermal robustness for cost-sensitive, high-volume linear and switching applications - especially where design margin and manufacturing repeatability are prioritized over peak gain or ultra-low V_CE(sat).

Availability

BC547ARL1G is available at Aetrix Electronics and suitable for audio pre-amplification, microcontroller GPIO expansion, linear regulator pass elements, and discrete logic level shifting requiring stable component supply and long-term manufacturability.

Supply support for BC547ARL1G 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 BC547ARL1G belongs to onsemi's legacy BC546–BC548 family of general-purpose NPN transistors, designed for broad adoption in cost-sensitive, high-reliability linear amplification and switching applications across industrial controls and consumer electronics.

FAQ

What is the maximum collector-emitter voltage rating for BC547ARL1G?

The BC547ARL1G has a maximum collector-emitter voltage (V_CEO) rating of 45 VDC, as specified in the onsemi BC546/D datasheet Rev. 5. This value represents the absolute maximum voltage that can be applied between collector and emitter with the base open before risking avalanche breakdown. Exceeding this rating may cause irreversible device failure, so designs must include sufficient voltage margin - typically ≥20% - for reliability under transient conditions.

Does BC547ARL1G have Pb-free construction?

Yes, BC547ARL1G is explicitly designated as Pb-free per onsemi's ordering nomenclature (the "G" suffix) and complies with RoHS Directive 2011/65/EU. Its TO-92 package uses lead-free matte tin plating on leads and halogen-free molding compound, validated per J-STD-609 and JEDEC JS-001 standards. This makes BC547ARL1G suitable for environmentally regulated production environments without compromising solder joint integrity in standard reflow profiles.

What is the DC current gain (h_FE) range for BC547ARL1G at 2 mA collector current?

The BC547ARL1G exhibits a DC current gain (h_FE) range of 110 to 220 when tested at I_C = 2.0 mA and V_CE = 5.0 V, per the Electrical Characteristics table in the BC546/D datasheet. This gain band reflects the "A" grade binning and is guaranteed for every unit shipped. Designers should use the minimum value (110) for worst-case bias calculations and verify thermal stability across the full operating temperature range.

Can BC547ARL1G be used in switching applications?

Yes, BC547ARL1G is routinely used in low-speed switching applications such as LED drivers and relay coils. Its V_CE(sat) ≤ 0.25 V at I_C = 10 mA / I_B = 0.5 mA and f_T ≥ 150 MHz support reliable turn-on/turn-off behavior up to ~1 MHz. For optimal switching, ensure base drive provides I_B ≥ I_C/10 to guarantee deep saturation, and include a base-emitter resistor to prevent leakage-induced turn-on during MCU reset.

What is the thermal resistance from junction to ambient (R_JA) for BC547ARL1G?

The BC547ARL1G has a junction-to-ambient thermal resistance (R_JA) of 200°C/W under standard free-air conditions, as stated in the Thermal Characteristics section of the BC546/D datasheet. This means each watt of power dissipated at the die raises its temperature 200°C above ambient. At its maximum rated power of 625 mW (T_A = 25°C), junction temperature would reach 150°C - the absolute maximum - so derating is essential: e.g., at 70°C ambient, max continuous power drops to ~375 mW.

BC547ARL1G Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-226-3, TO-92-3 Long Body, Formed Leads

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Transistor Type:: NPN

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

Voltage - Collector Emitter Breakdown (Max):: 45 V

Vce Saturation (Max) @ Ib, Ic:: 250mV @ 500µA, 10mA

Current - Collector Cutoff (Max):: 15nA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 110 @ 2mA, 5V

Power - Max:: 625 mW

Frequency - Transition:: 300MHz

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92 (TO-226)

BC547ARL1G FAQ

1.How can I place an order for BC547ARL1G through Aetrix?

Please submit a Request for Quotation (RFQ) for BC547ARL1G 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 BC547ARL1G reliable?

The price and inventory of BC547ARL1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC547ARL1G is usually 5 days.

3.What payment methods are accepted for BC547ARL1G?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC547ARL1G transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BC547ARL1G?

BC547ARL1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BC547ARL1G 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 BC547ARL1G?

For technical support, including BC547ARL1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC547ARL1G requirements.

6.How does Aetrix verify that BC547ARL1G is sourced from the original manufacturer or authorized distributors?

All BC547ARL1G 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 BC547ARL1G meets industry standards.

7.What is the process for return or replacement of BC547ARL1G?

All BC547ARL1G units undergo pre-shipment inspection (PSI). If there is an issue with BC547ARL1G, 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 BC547ARL1G part is unused and in its original packaging.

Return procedure for BC547ARL1G:

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…