onsemi PN3645_D27Z

Overview

PN3645_D27Z from Fairchild Semiconductor is a PNP general-purpose bipolar junction transistor designed for amplification and switching applications up to 500 mA collector current, with V_CEO = 60 V, h_FE = 40–300 (IC = 0.1–300 mA), and TO-92 package. It serves as a low-cost, through-hole discrete switch or small-signal amplifier in power management and interface circuits.

For engineers reviewing the PN3645_D27Z datasheet, pinout, applications, or equivalent options, key selection criteria include its PNP polarity, 60 V breakdown rating, 800 mA absolute max collector current, thermal resistance of 200 °C/W (junction-to-ambient), and compatibility with standard TO-92 PCB footprints and tape-and-reel automation (E-style reel, D27Z EOL code).

Technical Context

The PN3645_D27Z implements a silicon planar PNP BJT structure fabricated on Fairchild's Process 63, optimized for general-purpose linear amplification and saturated switching. Its DC current gain spans 40–300 across 0.1–300 mA collector currents, with V_CE(sat) ≤ 0.4 V at IC = 150 mA/IB = 15 mA and switching times (ton = 40 ns, toff = 100 ns) suitable for medium-speed digital control.

Thermal design is constrained by R_θJA = 200 °C/W and a maximum junction temperature of +150 °C, requiring heatsinking or derating above 25 °C ambient. The device shares electrical characteristics with the PN2907A but is distinct in process and packaging configuration per Fairchild documentation.

Key Specifications

Pinout & Package

PN3645_D27Z is supplied in a standard TO-92 plastic package with straight leads and no lead clip, compliant with EIAJ ED-7401A. The device uses Style "E" tape-and-reel configuration (EOL code D27Z), where the first wire off the package is the emitter, adhesive tape is on the top side, and the flat side of the transistor faces downward.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPSA92 and PN2907A, PN3645_D27Z provides optimal balance of 60 V capability, low V_CE(sat), and TO-92 tape-and-reel (D27Z) compatibility-making it ideal for mid-voltage industrial controls where reliability and assembly efficiency are prioritized over ultra-high breakdown or tight gain bins.

Availability

PN3645_D27Z is available at Aetrix Electronics and suitable for motor control interfaces, power supply sequencing, LED driver stages, and analog signal inversion requiring stable component supply and verified TO-92 tape-and-reel compatibility.

Supply support for PN3645_D27Z 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 components before its acquisition by ON Semiconductor in 2016. Its legacy products remain widely supported and qualified.

PN3645_D27Z belongs to Fairchild's general-purpose bipolar transistor product line, engineered for cost-effective amplification and switching in industrial, consumer, and computing systems where robustness and manufacturability are essential.

FAQ

What is the pin configuration of PN3645_D27Z in the TO-92 package?

The PN3645_D27Z uses a standard TO-92 package with emitter-base-collector (E-B-C) pinout when viewed with the flat side facing outward and leads pointing down. Pin 1 is emitter, pin 2 is base, and pin 3 is collector-matching Fairchild's Style "E" tape-and-reel specification (D27Z EOL code) where the first wire off is the emitter.

Does PN3645_D27Z support surface-mount assembly?

No, PN3645_D27Z is a through-hole TO-92 device and is not designed for SMT reflow. However, its D27Z tape-and-reel packaging supports automated insertion equipment. For SMT equivalents, consider SOT-23 PNP transistors like MMBT2907ALT1G-but note that those differ in voltage rating, gain, and thermal performance versus PN3645_D27Z.

What is the maximum power dissipation of PN3645_D27Z at 75°C ambient?

At 75°C ambient, PN3645_D27Z must be derated from its 625 mW maximum at 25°C by 5.0 mW/°C. This yields 625 − (50 × 5.0) = 375 mW maximum allowable power dissipation. Exceeding this risks junction temperature exceeding +150°C, potentially degrading long-term reliability.

How does PN3645_D27Z compare to the PN2907A in terms of DC current gain?

PN3645_D27Z specifies h_FE = 40–300 across IC = 0.1–300 mA, while PN2907A lists h_FE = 100–300 at IC = 10 mA. Both share Process 63, but PN3645_D27Z exhibits wider gain spread at low currents-making PN2907A preferable for precision biasing, whereas PN3645_D27Z remains suitable for general switching where exact gain is less critical.

Is PN3645_D27Z suitable for automotive applications?

PN3645_D27Z is not AEC-Q101 qualified and lacks automotive-grade screening or extended temperature validation beyond its −55 to +150°C junction rating. While it may function in non-safety-critical automotive modules (e.g., cabin lighting), Aetrix recommends AEC-Q101 PNP transistors such as the NSS2907AWT1G for production automotive use instead of PN3645_D27Z.