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 BC546ATAR

Name: BC546ATAR
Brand: onsemi
SKU: BC546ATAR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: BC546ATAR

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-226-3, TO-92-3 (TO-226AA) Formed Leads

Datasheet:: BC546ATAR.pdf

Description:: TRANS NPN 65V 0.1A TO-92-3

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:2,858

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

Product details

Overview

BC546ATAR from ON Semiconductor is a general-purpose NPN epitaxial silicon transistor in TO-92 package, rated for 65 V V_CEO, 100 mA I_C, and 500 mW P_C, widely used in low-power switching and linear amplification circuits such as signal buffering in sensor interfaces and discrete logic level translation.

For engineers reviewing the BC546ATAR datasheet, pinout, applications, or equivalent options, key selection criteria include DC current gain classification (h_FE = 110–220 for 'A' grade), V_CE(sat) at 10 mA/0.5 mA drive, noise figure under 200 µA bias, and TO-92 mechanical compatibility with manual prototyping and through-hole production.

Technical Context

The BC546ATAR belongs to the BC546–BC550 family of legacy bipolar junction transistors optimized for cost-sensitive, medium-frequency analog and digital applications up to ~300 MHz f_T. It operates with fixed base-emitter turn-on voltage (~660 mV typical at 2 mA) and exhibits predictable saturation behavior across its specified I_C range.

Its design targets discrete amplifier stages requiring moderate gain stability and low leakage (I_CBO ≤ 15 nA at 30 V), and switching nodes where V_CE(sat) ≤ 250 mV ensures minimal conduction loss at 10 mA collector current with 0.5 mA base drive.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	65 V - Maximum safe collector-emitter voltage before breakdown; enables use in 48 V rail monitoring and relay driver circuits.
I_C (DC)	100 mA - Continuous collector current rating; supports small-signal load switching without thermal derating at room temperature.
h_FE	110–220 - 'A' grade DC current gain range at V_CE = 5 V, I_C = 2 mA; ensures consistent biasing in emitter-follower and common-emitter amplifier designs.
V_CE(sat)	90–250 mV - Collector-emitter saturation voltage at I_C = 10 mA / I_B = 0.5 mA; defines minimum on-state voltage drop in switch-mode operation.
f_T	300 MHz - Current gain bandwidth product at V_CE = 5 V, I_C = 10 mA; supports audio and low-MHz RF preamplifier stages.
NF	2.0–10.0 dB - Noise figure at V_CE = 5 V, I_C = 200 µA, f = 1 kHz, R_G = 2 kΩ; suitable for low-noise microphone preamp input stages.

Pinout & Package

BC546ATAR is housed in a standard JEDEC TO-92 3-lead plastic package with straight leads (ammo pack format). Pin identification follows the conventional 1–2–3 layout when viewing the flat side with leads downward: Collector (1), Base (2), Emitter (3).

Pin/Terminal	Circuit Role	Design Meaning
1 (Top lead)	Collector	Main current sink terminal; connects to load or supply rail in common-emitter configuration.
2 (Center lead)	Base	Control electrode; requires current-limited drive (e.g., via 10 kΩ resistor) to achieve desired h_FE-dependent collector current.
3 (Bottom lead)	Emitter	Current source terminal; typically tied to ground or negative rail; provides reference for V_BE biasing.

Key Features

Feature	Design Value
High-voltage capability	V_CEO = 65 V allows direct interface with industrial 24–48 V control signals without external level-shifting.
Low collector leakage	I_CBO ≤ 15 nA at V_CB = 30 V ensures stable bias in high-impedance amplifier inputs over temperature.
Controlled h_FE binning	A-grade h_FE (110–220) enables predictable gain matching in multi-transistor circuits like differential pairs.
TO-92 mechanical standardization	JEDEC-compliant footprint supports hand-soldering, wave soldering, and automated insertion in legacy PCB assembly lines.

Applications

Audio Signal Amplification	Microcontroller GPIO Expansion
Use Scenario: Boosting weak line-level audio signals (≤100 mV_pp) before ADC sampling in embedded voice recorders. IC Role / Device Role / Timing Role: NPN common-emitter amplifier stage with fixed bias network and emitter degeneration resistor. Use Value: Delivers 20–30 dB voltage gain with <10 dB noise figure at 1 kHz, preserving SNR in battery-powered devices.	Use Scenario: Driving LED indicators or small relays from 3.3 V or 5 V microcontroller outputs with limited current sourcing capability. IC Role / Device Role / Timing Role: Low-side switch with saturated BJT operation controlled by MCU GPIO pin. Use Value: Enables 100 mA load switching using only 0.5 mA base current, reducing MCU I/O stress and eliminating need for dedicated driver ICs.
Sensor Interface Buffering	Discrete Logic Level Translation
Use Scenario: Isolating and amplifying output from resistive temperature sensors (RTDs) or photodiodes in analog front-end modules. IC Role / Device Role / Timing Role: Emitter-follower buffer providing high input impedance and low output impedance to prevent sensor loading. Use Value: Maintains signal fidelity with <1% gain error and <500 µV offset drift over 0°C–70°C ambient range.	Use Scenario: Converting 3.3 V logic outputs to 5 V or 12 V compatible levels for legacy peripherals in mixed-voltage systems. IC Role / Device Role / Timing Role: Common-emitter inverter with pull-up resistor on collector to translate voltage domains. Use Value: Achieves clean 5 V logic-high output with <100 ns propagation delay and no timing skew between multiple channels.

Audio Signal Amplification

Microcontroller GPIO Expansion

Use Scenario: Boosting weak line-level audio signals (≤100 mV_pp) before ADC sampling in embedded voice recorders.

IC Role / Device Role / Timing Role: NPN common-emitter amplifier stage with fixed bias network and emitter degeneration resistor.

Use Value: Delivers 20–30 dB voltage gain with <10 dB noise figure at 1 kHz, preserving SNR in battery-powered devices.

Use Scenario: Driving LED indicators or small relays from 3.3 V or 5 V microcontroller outputs with limited current sourcing capability.

IC Role / Device Role / Timing Role: Low-side switch with saturated BJT operation controlled by MCU GPIO pin.

Use Value: Enables 100 mA load switching using only 0.5 mA base current, reducing MCU I/O stress and eliminating need for dedicated driver ICs.

Sensor Interface Buffering

Discrete Logic Level Translation

Use Scenario: Isolating and amplifying output from resistive temperature sensors (RTDs) or photodiodes in analog front-end modules.

IC Role / Device Role / Timing Role: Emitter-follower buffer providing high input impedance and low output impedance to prevent sensor loading.

Use Value: Maintains signal fidelity with <1% gain error and <500 µV offset drift over 0°C–70°C ambient range.

Use Scenario: Converting 3.3 V logic outputs to 5 V or 12 V compatible levels for legacy peripherals in mixed-voltage systems.

IC Role / Device Role / Timing Role: Common-emitter inverter with pull-up resistor on collector to translate voltage domains.

Use Value: Achieves clean 5 V logic-high output with <100 ns propagation delay and no timing skew between multiple channels.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BC546BTA	Same TO-92 package and pinout; higher h_FE bin (200–450) vs. BC546ATAR's 110–220.	Improved current gain reduces required base drive in low-power battery applications but may increase sensitivity to thermal drift.	Select BC546BTA when tighter gain tolerance or lower base current is critical; verify bias stability across operating temperature.
PN2222A	Higher V_CEO (40 V vs. 65 V), higher I_C (800 mA), different h_FE distribution (100–300), same TO-92 package.	Better suited for higher-current switching (e.g., solenoid drivers); less optimal for low-noise amplification due to higher NF.	Choose PN2222A for loads >100 mA or where robustness against transient overvoltage is secondary to current handling.

Compared with BC546BTA and PN2222A, BC546ATAR offers the highest V_CEO among TO-92 NPN transistors in its class, making it uniquely suitable for 48 V industrial signal conditioning where voltage margin is critical, while maintaining low-noise performance at microampere bias currents.

Availability

BC546ATAR is available at Aetrix Electronics and suitable for audio signal conditioning, microcontroller peripheral interfacing, sensor buffering, and discrete logic translation requiring stable component supply and long-term obsolescence management.

Supply support for BC546ATAR 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

ON Semiconductor is a global semiconductor manufacturer specializing in power management, analog, sensor, and discrete solutions for automotive, industrial, and consumer markets.

The BC546ATAR belongs to ON Semiconductor's legacy general-purpose bipolar transistor product line, designed for cost-effective, reliable discrete amplification and switching in non-critical, high-volume electronic assemblies.

FAQ

What is the maximum collector-emitter voltage rating for BC546ATAR?

The BC546ATAR has a V_CEO rating of 65 V, verified per its absolute maximum ratings table. This value represents the maximum DC voltage that can be applied between collector and emitter with the base open, and must not be exceeded to avoid device breakdown. BC546ATAR maintains this rating across its full operating temperature range.

Is BC546ATAR pin-compatible with other BC54x-series transistors?

Yes, BC546ATAR shares identical TO-92 pinout (Collector–Base–Emitter, left-to-right when viewing flat side) with all BC546/547/548/549/550 variants. However, electrical parameters-including V_CEO, h_FE, and noise figure-differ across the series, so direct substitution requires verification of circuit bias conditions and gain requirements.

What h_FE classification does BC546ATAR have?

BC546ATAR is an 'A' grade device with DC current gain (h_FE) specified from 110 to 220 at V_CE = 5 V and I_C = 2 mA. This binning ensures predictable amplification behavior in bias-critical applications such as emitter followers and low-gain preamplifiers where tight gain spread is required.

Can BC546ATAR be used in low-noise audio applications?

Yes, BC546ATAR delivers a noise figure of 2.0–10.0 dB at V_CE = 5 V, I_C = 200 µA, f = 1 kHz, and R_G = 2 kΩ, making it suitable for microphone preamplifier inputs and other low-level analog signal paths where noise contribution must remain below 10 dB. Its low I_CBO further enhances stability in high-Z nodes.

What packaging format does BC546ATAR use?

BC546ATAR is supplied in TO-92 3-lead plastic package with ammo packing (tape-and-reel not used for this variant). The straight-lead configuration complies with JEDEC TO-92 standards and supports both manual prototyping and automated through-hole assembly processes.

BC546ATAR Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-226-3, TO-92-3 (TO-226AA) Formed Leads

Packaging:: Tape & Box (TB)

Product Status:: Obsolete

Transistor Type:: NPN

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

Voltage - Collector Emitter Breakdown (Max):: 65 V

Vce Saturation (Max) @ Ib, Ic:: 600mV @ 5mA, 100mA

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

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

Power - Max:: 500 mW

Frequency - Transition:: 300MHz

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92-3

BC546ATAR FAQ

1.How can I place an order for BC546ATAR through Aetrix?

Please submit a Request for Quotation (RFQ) for BC546ATAR 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 BC546ATAR reliable?

The price and inventory of BC546ATAR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC546ATAR is usually 5 days.

3.What payment methods are accepted for BC546ATAR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC546ATAR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BC546ATAR?

BC546ATAR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BC546ATAR 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 BC546ATAR?

For technical support, including BC546ATAR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC546ATAR requirements.

6.How does Aetrix verify that BC546ATAR is sourced from the original manufacturer or authorized distributors?

All BC546ATAR 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 BC546ATAR meets industry standards.

7.What is the process for return or replacement of BC546ATAR?

All BC546ATAR units undergo pre-shipment inspection (PSI). If there is an issue with BC546ATAR, 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 BC546ATAR part is unused and in its original packaging.

Return procedure for BC546ATAR:

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…