onsemi BC547_J61Z

Overview

BC547_J61Z from ON Semiconductor is an NPN epitaxial silicon transistor designed for general-purpose switching and low-noise amplification in discrete analog circuits. It features V_CEO = 45 V, I_C = 100 mA, P_C = 500 mW, h_FE range of 110–800 (depending on grade), and f_T = 300 MHz - enabling use in audio preamps, relay drivers, and signal conditioning stages.

For engineers reviewing the BC547_J61Z datasheet, pinout, applications, or equivalent options, key selection criteria include DC current gain classification (A/B/C), saturation voltage at defined I_C/I_B, noise figure (2.0–10.0 dB), and TO-92 thermal derating behavior under continuous operation.

Technical Context

The BC547_J61Z operates as a single NPN bipolar junction transistor with epitaxial base construction, optimized for linear amplification and saturated switching. Its h_FE classification (per marking) determines small-signal gain consistency across production lots, while V_CE(sat) ≤ 250 mV at I_C = 10 mA / I_B = 0.5 mA defines low-loss switching capability.

Thermal performance is governed by TO-92 package limitations: P_C derates linearly above 25°C ambient, and T_J(max) = 150°C constrains high-current pulse duty cycles. Noise figure (2.0–10.0 dB at 1 kHz) and f_T = 300 MHz confirm suitability for audio-frequency amplifiers and RF front-end biasing, not RF power stages.

Key Specifications

Pinout & Package

BC547_J61Z is housed in a standard JEDEC TO-92 3-lead plastic package with straight leads (bulk or ammo packaging). Thermal resistance θ_JA ≈ 200°C/W limits sustained power dissipation to <150 mW at 70°C ambient without heatsinking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC547C and 2N3904, BC547_J61Z offers balanced trade-offs: higher V_CEO than 2N3904 for ruggedness in noisy environments, and broader h_FE availability than BC547C for cost-sensitive designs where gain variation is acceptable.

Availability

BC547_J61Z is available at Aetrix Electronics and suitable for audio preamplifiers, relay driver circuits, and LED current regulators requiring stable component supply across industrial, instrumentation, and consumer electronics programs.

Supply support for BC547_J61Z 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, and discrete solutions for automotive, industrial, and cloud infrastructure markets.

The BC547_J61Z belongs to ON Semiconductor's legacy general-purpose transistor family, originally developed by Fairchild Semiconductor to deliver reliable, low-cost NPN switching and amplification in through-hole and automated assembly environments.

FAQ

What is the exact h_FE range for BC547_J61Z?

The BC547_J61Z does not specify its h_FE grade (A/B/C) in the J-column data or associated documentation. Per the BC546–BC550 family datasheet, h_FE ranges are: A = 110–220, B = 200–450, C = 420–800. To guarantee h_FE, select explicitly marked variants like BC547BTA or BC547CTA. BC547_J61Z must be tested per unit or sourced with grade confirmation.

Is BC547_J61Z pin-compatible with BC546 or BC548?

Yes - BC547_J61Z shares identical TO-92 pinout (1 = Collector, 2 = Base, 3 = Emitter) and mechanical dimensions with BC546, BC548, BC549, and BC550. All exhibit the same lead configuration and solder footprint, enabling physical interchangeability in PCB layouts designed for this family.

Does BC547_J61Z support low-noise audio applications?

Yes - BC547_J61Z inherits the BC547 family's low-noise capability: NF = 2.0–10.0 dB at 1 kHz, 200 μA I_C. When operated at I_C ≈ 200 μA–2 mA with proper emitter degeneration and bypassing, it delivers measurable SNR improvement over standard switching transistors in microphone preamp stages.

What is the maximum safe operating temperature for BC547_J61Z?

The BC547_J61Z has a maximum junction temperature (T_J) of 150°C and storage range of –65°C to +150°C. In practice, sustained operation above 100°C case temperature requires derating: P_C decreases by ~5 mW/°C above 25°C ambient. For reliability, keep T_J < 125°C under continuous load.

Can BC547_J61Z replace a 2N2222 in existing designs?

BC547_J61Z can substitute for 2N2222 in low-current (<100 mA), low-voltage (<45 V) roles, but caution is needed: 2N2222 has V_CEO = 40 V and P_C = 500 mW - matching BC547_J61Z's ratings. However, 2N2222's h_FE (35–300) and f_T (250 MHz) differ slightly; verify gain stability and switching speed in the target circuit before replacement.