onsemi PN4249_D74Z

Overview

PN4249_D74Z from Fairchild Semiconductor is a PNP general-purpose bipolar junction transistor (BJT) designed for amplification and switching in low-to-medium power circuits, with V_CEO = 60 V, I_C = 500 mA continuous, h_FE = 100–300 at I_C = 100 µA, and TO-92 radial ammo packaging (EOL code D74Z). It serves in discrete signal conditioning and load control applications up to 300 mA collector current.

For engineers reviewing the PN4249_D74Z datasheet, pinout, applications, or equivalent options, key selection criteria include its PNP polarity, 60 V breakdown rating, thermal resistance of 200 °C/W (J-A), DC current gain range, and TO-92 mechanical compatibility with standard through-hole PCB layouts.

Technical Context

The PN4249_D74Z operates as a silicon PNP BJT fabricated on Fairchild's Process 68, optimized for general-purpose linear amplification and saturated switching. Its electrical behavior is defined by V_CE(sat) ≤ 0.25 V at I_C = 10 mA / I_B = 0.5 mA and noise figure of 3.0 dB under specified 1 kHz/250 µA conditions.

Thermal performance is characterized by R_θJA = 200 °C/W and R_θJC = 83.3 °C/W, supporting operation across –55 °C to +150 °C junction temperature. Small-signal parameters include h_ie = 2.5–17 kΩ and C_ob = 6.0 pF at 5 V V_CB, confirming suitability for audio-frequency and low-speed digital switching.

Key Specifications

Pinout & Package

PN4249_D74Z is supplied in TO-92 plastic package with radial ammo tape configuration (EOL code D74Z), flat side down, emitter lead exiting first. Package outline conforms to JEDEC TO-92 standard (FS PKG Code 92), with 0.1977 g unit weight and 2000 units per ammo box.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPSA92 and BC557, PN4249_D74Z delivers balanced performance across voltage (60 V), current (500 mA), and gain (100–300), making it optimal for mid-range industrial switching and amplification where reliability and thermal margin are prioritized over extreme voltage or ultra-low power.

Availability

PN4249_D74Z is available at Aetrix Electronics and suitable for industrial control systems, sensor interface modules, and discrete power management circuits requiring stable component supply and long-term manufacturability.

Supply support for PN4249_D74Z 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 manufacturer specializing in power management, analog, and discrete components before its acquisition by ON Semiconductor in 2016.

The PN4249_D74Z belongs to Fairchild's legacy general-purpose BJT family, engineered for cost-effective, robust amplification and switching in industrial, automotive, and consumer electronics where proven reliability and wide operating margins are essential.

FAQ

What is the pin configuration of PN4249_D74Z in TO-92 radial ammo packaging?

PN4249_D74Z uses standard TO-92 pinout: Emitter (first lead), Base (center), Collector (third lead), with flat side down and adhesive tape on bottom. This matches JEDEC TO-92 orientation for automated placement and manual soldering. The D74Z EOL code confirms radial ammo packaging with emitter-first lead sequence.

Does PN4249_D74Z support operation at elevated temperatures?

Yes, PN4249_D74Z is rated for junction temperatures from –55 °C to +150 °C, with thermal resistance R_θJA = 200 °C/W. At full 625 mW dissipation, ambient temperature must remain ≤ 25 °C unless heatsinking or forced airflow is applied. Derating is required above 25 °C at 5.0 mW/°C.

Can PN4249_D74Z be used as a direct replacement for PN2222A in a circuit?

No - PN4249_D74Z is a PNP transistor, while PN2222A is NPN. They are complementary types, not interchangeable. Swapping them would invert logic polarity and likely cause circuit failure. Use PN4249_D74Z only in PNP-specific topologies such as high-side switches or inverting amplifiers.

What is the maximum safe collector current for continuous DC operation of PN4249_D74Z?

The absolute maximum continuous collector current for PN4249_D74Z is 500 mA at T_A = 25 °C. Operation above this value risks thermal runaway or permanent damage unless derated per the 5.0 mW/°C thermal specification and verified with actual board-level thermal measurements.

Is PN4249_D74Z compliant with RoHS and REACH requirements?

PN4249_D74Z was manufactured prior to Fairchild's full RoHS transition and carries no explicit RoHS marking in its original documentation. For compliance-critical designs, consult ON Semiconductor's current product cross-reference or request material declarations directly from Aetrix Electronics' quality team before release.