onsemi BC547A_J35Z

Overview

BC547A_J35Z from ON Semiconductor is a general-purpose NPN epitaxial silicon transistor used for low-power switching and small-signal amplification in discrete analog and digital circuits. It features V_CEO = 45 V, I_C = 100 mA, h_FE = 110–220 (Class A), P_C = 500 mW, and TO-92 package - commonly deployed in sensor interface stages, LED drivers, and logic-level translation.

For engineers reviewing the BC547A_J35Z datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, terminal mapping, real-world use cases, and validated alternative parts - all aligned to Fairchild/ON Semiconductor's official BC547 family specification Rev. 1.1.1.

Technical Context

The BC547A_J35Z operates as a single NPN bipolar junction transistor with epitaxial base construction, optimized for linear amplification and saturated switching. Its DC current gain (h_FE) is binned to Class A (110–220) at V_CE = 5 V and I_C = 2 mA, and it exhibits V_CE(sat) ≤ 250 mV at I_C = 10 mA / I_B = 0.5 mA.

It supports operation up to f_T = 300 MHz under specified bias conditions (V_CE = 5 V, I_C = 10 mA), with Cob = 3.5–6.0 pF and Cib ≈ 9 pF - confirming suitability for audio-frequency and low-MHz signal paths. Junction temperature rating is 150°C, and storage range spans −65°C to +150°C.

Key Specifications

Pinout & Package

BC547A_J35Z is housed in a standard JEDEC TO-92 3-lead plastic package with straight leads (bulk or ammo packing). Pin identification follows the conventional emitter-base-collector (E-B-C) sequence when viewing the flat side with leads downward.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC547B and 2N3904, BC547A_J35Z offers the lowest h_FE bin (110–220) for predictable base current calculation, best V_CEO margin among common TO-92 NPNs, and documented low-noise behavior - making it optimal for cost-sensitive, stable-gain analog interfaces.

Availability

BC547A_J35Z is available at Aetrix Electronics and suitable for audio preamplifiers, LED driver circuits, logic level translators, and relay driver interfaces requiring stable component supply across prototyping, pilot production, and long-life industrial deployments.

Supply support for BC547A_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 (formerly Fairchild Semiconductor) is a global supplier of energy-efficient semiconductor components, specializing in power management, analog, and discrete devices for automotive, industrial, and consumer markets.

BC547A_J35Z belongs to the BC546–BC550 NPN transistor family designed for general-purpose amplification and switching in cost-sensitive, high-reliability through-hole applications - emphasizing manufacturability, thermal stability, and broad parameter consistency.

FAQ

What is the maximum collector-emitter voltage rating for BC547A_J35Z?

The BC547A_J35Z has a V_CEO rating of 45 V, meaning it can safely sustain up to 45 volts between collector and emitter terminals under open-base conditions at T_A = 25°C. This value is confirmed in the Fairchild/ON Semiconductor BC546–BC550 datasheet Rev. 1.1.1 and must be derated linearly above 25°C ambient temperature. Exceeding this limit risks avalanche breakdown or permanent device failure.

Is BC547A_J35Z pin-compatible with other BC547 variants like BC547B or BC547C?

Yes, BC547A_J35Z shares identical TO-92 package dimensions and pinout (E-B-C) with BC547B and BC547C. All variants use the same physical layout and terminal assignment, allowing direct PCB substitution. However, h_FE bins differ: BC547A_J35Z is Class A (110–220), BC547B is Class B (200–450), and BC547C is Class C (420–800), so circuit performance may vary if gain sensitivity is critical.

Does BC547A_J35Z support low-noise audio applications?

Yes, BC547A_J35Z is explicitly characterized for low-noise operation with a noise figure of 2.0–10.0 dB at 1 kHz (V_CE = 5 V, I_C = 200 μA, R_G = 2 kΩ), per the BC546–BC550 datasheet. This makes it suitable for microphone preamplifiers and sensor signal conditioning where signal integrity is prioritized over ultra-high gain.

What is the typical DC current gain (h_FE) of BC547A_J35Z at 2 mA collector current?

The BC547A_J35Z has a guaranteed h_FE range of 110 to 220 when measured at V_CE = 5 V and I_C = 2 mA, as defined by its Class A binning in the official datasheet. This range allows predictable base resistor selection for bias networks and ensures consistent switching thresholds in digital interface applications.

Can BC547A_J35Z replace BC546A in existing designs?

BC547A_J35Z can replace BC546A in most designs, but with caution: BC546A has higher V_CEO (65 V) and V_CBO (80 V) than BC547A_J35Z (45 V and 50 V respectively). If the original design operates near BC546A's voltage limits, BC547A_J35Z may not provide sufficient margin. Otherwise, identical package, pinout, and overlapping h_FE make it a functional substitute where voltage stress is moderate.