onsemi BC546A_J35Z

Overview

BC546A_J35Z from ON Semiconductor is an NPN epitaxial silicon transistor designed for general-purpose switching and low-noise amplification, with V_CEO = 65 V, h_FE = 110–220 (Class A), and f_T = 300 MHz. It operates in TO-92 package and is commonly used in audio preamplifiers, signal conditioning stages, and discrete logic-level switching circuits.

For engineers reviewing the BC546A_J35Z datasheet, pinout, applications, or equivalent options, key selection criteria include DC current gain classification (Class A), collector-emitter breakdown voltage, saturation voltage at defined drive conditions, noise figure in low-current amplifier configurations, and TO-92 mechanical compatibility across legacy designs.

Technical Context

This device belongs to the BC546–BC550 family of through-hole NPN transistors standardized under JEDEC TO-92. Its Class A h_FE binning (110–220) targets stable biasing in linear amplifier stages where moderate gain consistency is required without tight tolerance control.

It features a 65 V V_CEO rating and 100 mA I_C continuous rating, enabling use in low-power supply rail switching up to ±30 V systems. The 300 MHz f_T supports RF front-end amplification up to ~100 MHz when operated within safe SOA limits.

Key Specifications

Pinout & Package

BC546A_J35Z is housed in a standard JEDEC TO-92 plastic package with straight leads (bulk configuration). Lead identification follows conventional orientation: flat side facing viewer, leads down, left-to-right = Emitter (1), Base (2), Collector (3).

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC546A_J35Z, BC547A offers identical gain binning but reduced voltage margin, while 2N3904 provides broader global availability and same f_T, yet lacks guaranteed V_CEO and h_FE consistency-making BC546A_J35Z preferable for 65 V–capable, gain-stable designs.

Availability

BC546A_J35Z is available at Aetrix Electronics and suitable for audio preamplifiers, discrete logic-level switching, and linear voltage regulator pass elements requiring stable component supply across long-lifecycle industrial and consumer programs.

Supply support for BC546A_J35Z 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 energy-efficient power management, analog, sensor, and logic solutions for automotive, industrial, and cloud infrastructure markets.

The BC546A_J35Z belongs to ON Semiconductor's legacy general-purpose bipolar transistor product line, originally developed by Fairchild and maintained for backward compatibility in cost-sensitive, through-hole-based designs requiring proven reliability and wide temperature operation.

FAQ

What is the maximum collector-emitter voltage rating for BC546A_J35Z?

The BC546A_J35Z has a V_CEO rating of 65 V, meaning it can safely sustain up to 65 volts between collector and emitter with the base open. This rating is confirmed in the Absolute Maximum Ratings table of the official ON Semiconductor datasheet for the BC546 family. Exceeding this voltage risks avalanche breakdown and permanent device failure. Always maintain at least 20% derating margin in production designs using BC546A_J35Z.

What does the "A" suffix indicate in BC546A_J35Z?

The "A" in BC546A_J35Z denotes the h_FE (DC current gain) classification bin: 110–220 at V_CE = 5 V and I_C = 2 mA. This binning ensures predictable base drive requirements in production amplifier and switching circuits. The J35Z marking is a date/batch code per ON Semiconductor's internal traceability system and does not affect electrical specifications of BC546A_J35Z.

Is BC546A_J35Z compatible with TO-92 sockets and automated assembly equipment?

Yes, BC546A_J35Z uses a standard JEDEC TO-92 package with straight leads conforming to bulk-type mechanical dimensions. It fits industry-standard TO-92 sockets and is compatible with wave soldering, selective soldering, and manual rework tools. The lead pitch and body profile match IPC-7351B TO-92 footprint guidelines, ensuring reliable placement and solder joint formation in BC546A_J35Z-based assemblies.

What is the typical noise figure of BC546A_J35Z and under what conditions is it specified?

The BC546A_J35Z has a noise figure of 2.0–10.0 dB, measured at V_CE = 5 V, I_C = 200 μA, f = 1 kHz, and R_G = 2 kΩ. This specification applies specifically to low-current, low-frequency amplifier applications such as microphone preamplifiers. Noise performance degrades above 10 kHz and under higher collector currents, so BC546A_J35Z should be biased near 200 μA for optimal SNR in sensitive analog front-ends.

Can BC546A_J35Z replace BC547A in an existing circuit without modification?

BC546A_J35Z can replace BC547A in most circuits, but only if the application operates below 45 V collector-emitter voltage. Since BC546A_J35Z has a higher V_CEO (65 V vs. 45 V) and identical h_FE Class A range, it adds voltage margin without altering gain or switching behavior. However, verify SOA compliance under worst-case transients before substituting BC546A_J35Z for BC547A in field-deployed hardware.