onsemi BC846AMTF

Overview

BC846AMTF from onsemi is an NPN epitaxial silicon transistor in SOT-23 package, rated for 80 V collector-base voltage, 65 V collector-emitter voltage, and 100 mA DC collector current, with hFE classification A (110–220) and 300 MHz fT - used in low-noise amplifier stages and general-purpose switching in consumer power management circuits.

For engineers reviewing the BC846AMTF datasheet, pinout, applications, or equivalent options, key selection criteria include V_CEO = 65 V, hFE = 110–220 at I_C = 2 mA, V_CE(sat) ≤ 250 mV at I_C = 10 mA/I_B = 0.5 mA, f_T = 300 MHz, and SOT-23 thermal resistance of 403 °C/W.

Technical Context

This device operates as a discrete NPN bipolar junction transistor optimized for linear amplification and digital switching. Its 300 MHz f_T, low V_BE(on) (580–700 mV), and 3.5–6.0 pF C_ob support stable small-signal gain up to mid-VHF range while maintaining low input/output capacitance.

The BC846AMTF belongs to the BC846/BC847/BC848/BC850 family with fixed SOT-23 pinout (1: Base, 2: Emitter, 3: Collector), standardized hFE binning (A/B/C), and shared absolute maximum ratings except for V_CBO/V_CEO - where BC846 variants specify higher voltage tolerance than BC847/BC848.

Key Specifications

Pinout & Package

SOT-23 3-lead plastic surface-mount package with standard JEDEC MO-215 footprint and thermal pad omitted. Pin 1 = Base, Pin 2 = Emitter, Pin 3 = Collector - compatible with automated pick-and-place and reflow soldering.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC846BMTF, BC846AMTF offers lower and more predictable hFE spread for deterministic bias design; versus MMBT3904LT1G, it provides 25 V higher V_CEO headroom critical in industrial power supplies and automotive body electronics.

Availability

BC846AMTF is available at Aetrix Electronics and suitable for audio preamplifiers, LED driver circuits, logic-level interfaces, and small relay drivers requiring stable component supply and long-term manufacturability.

Supply support for BC846AMTF 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 manufacturer specializing in energy-efficient power, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The BC846AMTF belongs to onsemi's general-purpose bipolar transistor product line, designed for reliable, cost-effective switching and amplification in space-constrained surface-mount applications across industrial controls and consumer electronics.

FAQ

What is the maximum collector-emitter voltage rating for BC846AMTF?

The BC846AMTF has a maximum collector-emitter voltage (V_CEO) rating of 65 V at T_A = 25°C. This rating remains valid under continuous DC operation and defines the upper limit for safe voltage swing across the collector and emitter terminals without risk of avalanche breakdown. Exceeding this value may cause irreversible device failure.

What does the "A" suffix in BC846AMTF indicate?

The "A" in BC846AMTF denotes the hFE (DC current gain) classification bin, specifying a minimum hFE of 110 and maximum of 220 when measured at V_CE = 5 V and I_C = 2 mA. This binning enables predictable gain behavior in production designs and supports consistent bias point selection across manufacturing lots of BC846AMTF.

Is BC846AMTF suitable for RF amplifier applications?

Yes, BC846AMTF is suitable for RF amplifier applications up to approximately 100 MHz due to its 300 MHz current gain–bandwidth product (f_T). Its low output capacitance (C_ob = 3.5–6.0 pF) and stable hFE across temperature support broadband small-signal amplification in VHF front-end stages, though layout parasitics must be minimized for optimal performance.

What is the thermal resistance (R_θJA) of BC846AMTF?

The BC846AMTF has a junction-to-ambient thermal resistance (R_θJA) of 403 °C/W under standard test conditions (FR-4 PCB, 76 mm × 114 mm, minimum land pattern). This value determines how much the junction temperature rises per milliwatt of power dissipated and confirms suitability for 310 mW operation without forced cooling on typical layouts.

Does BC846AMTF require a base resistor in switching applications?

Yes, BC846AMTF requires an external base resistor to limit base current and ensure proper saturation. For example, with a 3.3 V MCU GPIO driving the base and V_BE(sat) ≈ 0.7 V, a 2.2 kΩ resistor limits I_B to ~1.2 mA - sufficient to saturate the transistor at I_C = 10–20 mA. Omitting this resistor risks excessive base current and potential device damage.