onsemi PN3565

Overview

PN3565 from Fairchild Semiconductor is an NPN general-purpose bipolar junction transistor (BJT) designed for amplification and switching in low-to-medium power circuits, with confirmed V_CEO = 25 V, I_C = 500 mA continuous, h_FE = 150–600 at I_C = 1.0 mA, V_CE(sat) = 0.35 V, and TO-92 package. It serves in signal conditioning, logic-level interfacing, and load switching up to 300 mA collector current.

For engineers reviewing the PN3565 datasheet, pinout, applications, or equivalent options, key selection considerations include its DC current gain range, saturation voltage under defined bias conditions, thermal resistance (R_θJA = 200 °C/W), breakdown voltage margins, and compatibility with through-hole PCB assembly using standard TO-92 footprints.

Technical Context

The PN3565 operates as a silicon NPN BJT fabricated on Process 10, optimized for general-purpose linear amplification and saturated switching. Its h_FE variation (150–600) reflects process spread across production lots, and its small-signal h_fe reaches 750 at 1 kHz but drops to 12 at 20 MHz - confirming bandwidth-limited utility in audio and low-speed digital applications.

Thermal design is constrained by R_θJA = 200 °C/W and P_D = 625 mW at T_A = 25°C, derating 5.0 mW/°C above ambient. Junction temperature must remain ≤150°C; operation beyond absolute maximum ratings - including V_CBO = 30 V and V_EBO = 6.0 V - risks irreversible device degradation.

Key Specifications

Pinout & Package

PN3565 is housed in a standard TO-92 plastic package with 3 leads, lead-forming option "straight" (no clip), and pinout verified per Fairchild's Figure 1.0: Emitter (lead 1), Base (lead 2), Collector (lead 3), viewed from flat side with leads down and flat facing viewer.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PN3565, PN2222A offers higher voltage and current margins but narrower h_FE range, while BC547B provides tighter gain control at reduced current capacity and requires pinout-aware layout - making PN3565 optimal for cost-sensitive, medium-current switching where 25 V ceiling and TO-92 E-B-C alignment are design constraints.

Availability

PN3565 is available at Aetrix Electronics and suitable for audio pre-amplifier stages, microcontroller GPIO expanders, DC motor speed control, and industrial sensor interfaces requiring stable component supply and long-term obsolescence management.

Supply support for PN3565 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

Fairchild Semiconductor was a U.S.-based semiconductor company specializing in power management, analog, and discrete devices, acquired by ON Semiconductor in 2016.

The PN3565 belongs to Fairchild's legacy general-purpose transistor family, engineered for broad utility in cost-sensitive consumer, industrial, and educational electronics where reliability, manufacturability, and ease of use outweigh ultra-high performance demands.

FAQ

What is the maximum continuous collector current rating for PN3565?

The PN3565 has an absolute maximum continuous collector current (I_C) rating of 500 mA at T_A = 25°C. However, the device is functionally specified for use up to 300 mA in general-purpose amplifier and switching applications, consistent with its thermal limits and guaranteed h_FE performance. Exceeding 300 mA requires careful thermal design due to R_θJA = 200 °C/W.

Does PN3565 have a documented pinout configuration, and what is it?

Yes, PN3565 uses the standard TO-92 package with Emitter-Base-Collector (E-B-C) pinout: when viewing the flat side of the package with leads pointing downward, Lead 1 (left) is Emitter, Lead 2 (center) is Base, and Lead 3 (right) is Collector. This matches Fairchild's Figure 1.0 and is distinct from BC547-type E-C-B orientation.

What is the DC current gain (h_FE) range for PN3565, and at what conditions is it specified?

The PN3565 exhibits h_FE = 150 to 600, measured at V_CE = 10 V and I_C = 1.0 mA. This wide spread reflects inherent process variation in Process 10 fabrication and informs base resistor selection - designs should accommodate the full range to ensure robust saturation or linear operation across production units.

Can PN3565 be used in switching applications, and what saturation performance does it offer?

Yes, PN3565 is explicitly designed for switching applications requiring collector currents up to 300 mA. Its V_CE(sat) is specified at 0.35 V when I_C = 1.0 mA and I_B = 0.1 mA, indicating strong saturation behavior. For higher currents, actual V_CE(sat) remains low (<0.5 V) with appropriate base overdrive, enabling efficient low-side switching.

Is PN3565 suitable for high-frequency signal amplification, and what limits its bandwidth?

No, PN3565 is not optimized for high-frequency amplification. Its small-signal current gain h_fe falls to 12 at 20 MHz, and output capacitance C_ob = 4.0 pF contributes to frequency-dependent roll-off. The device is best suited for audio-band (<20 kHz) and low-speed digital switching; RF or broadband applications require transistors with higher f_T and lower C_ob.