onsemi 2N4403_J18Z

Overview

2N4403_J18Z from Fairchild Semiconductor is a PNP bipolar junction transistor (BJT) designed for general-purpose amplification and switching up to 500 mA collector current, with V_CEO = 40 V, V_CB0 = 40 V, and V_EB0 = 5.0 V, housed in a TO-92 package. It delivers h_FE ≥ 100 at I_C = 10 mA and supports fast switching with t_d = 15 ns, t_r = 20 ns, and t_s = 225 ns - commonly used in low-voltage relay drivers and signal inversion stages.

For engineers reviewing the 2N4403_J18Z datasheet, pinout, applications, or equivalent options, key selection criteria include verified PNP polarity, TO-92 mechanical compatibility, guaranteed h_FE range across I_C = 0.1–500 mA, thermal resistance R_θJA = 200 °C/W on standard FR-4, and validated switching performance under V_CC = 30 V, I_C = 150 mA conditions.

Technical Context

The 2N4403_J18Z operates as a medium-speed, medium-current PNP BJT optimized for linear amplification and saturated switching. Its f_T = 200 MHz enables audio-frequency gain stability, while C_cb = 8.5 pF and C_eb = 30 pF define high-frequency input/output impedance behavior.

Thermal design relies on its R_θJA = 200 °C/W (TO-92, free-air) and P_D = 625 mW at T_A = 25 °C, derating at 5.0 mW/°C above ambient. Junction temperature is rated from –55 °C to +150 °C, supporting industrial and automotive under-hood environments when properly heatsinked.

Key Specifications

Pinout & Package

2N4403_J18Z uses the TO-92 through-hole plastic package (3-lead, straight lead form), with standardized pinout: Emitter (E), Base (B), Collector (C) - viewed from flat side with leads down, left-to-right is E-B-C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMBT4403 and 2N3906, the 2N4403_J18Z uniquely balances 600 mA absolute rating, TO-92 mechanical robustness, and 225 ns storage time - making it optimal for cost-sensitive, medium-current industrial switching where manual assembly or thermal margin is prioritized over footprint size or ultra-high speed.

Availability

2N4403_J18Z is available at Aetrix Electronics and suitable for relay drivers, LED current sinks, level-shifting inverters, and audio preamplifiers requiring stable component supply across production lifecycles.

Supply support for 2N4403_J18Z 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 before its acquisition by ON Semiconductor in 2016.

The 2N4403_J18Z belongs to Fairchild's legacy general-purpose PNP BJT family, engineered for cost-effective, reliable switching and amplification in industrial controls, consumer electronics, and automotive subsystems.

FAQ

What is the maximum continuous collector current rating for the 2N4403_J18Z?

The 2N4403_J18Z has an absolute maximum continuous collector current (I_C) rating of 600 mA, though its design intent specifies reliable operation up to 500 mA in saturated switching applications. This rating assumes proper thermal management - specifically, maintaining junction temperature below 150 °C using the TO-92 package's R_θJA = 200 °C/W characteristic on standard FR-4 PCBs.

Is the 2N4403_J18Z pin-compatible with the MMBT4403?

No - the 2N4403_J18Z (TO-92) and MMBT4403 (SOT-23) have different physical packages and pinouts. While both share identical electrical specifications and PNP polarity, the 2N4403_J18Z uses E-B-C left-to-right viewing from the flat side, whereas the MMBT4403 follows SOT-23 pin 1 = E, pin 2 = B, pin 3 = C. PCB layout and assembly processes are not interchangeable.

What is the typical storage time (t_s) of the 2N4403_J18Z under standard test conditions?

The 2N4403_J18Z exhibits a typical storage time (t_s) of 225 ns when tested at V_CC = 30 V, I_C = 150 mA, and I_B1 = I_B2 = 15 mA. This value is critical for calculating total turn-off delay in PWM-driven loads and confirms suitability for switching frequencies up to approximately 1 MHz in well-designed gate-drive circuits.

Does the 2N4403_J18Z support operation at elevated ambient temperatures?

Yes - the 2N4403_J18Z is rated for operation from –55 °C to +150 °C junction temperature. At ambient temperatures up to 70 °C, it can safely dissipate ≥300 mW with no additional heatsinking, based on its R_θJA = 200 °C/W. For sustained operation above 85 °C ambient, derating or airflow must be applied to maintain T_J ≤ 150 °C.

What is the minimum guaranteed DC current gain (h_FE) for the 2N4403_J18Z at I_C = 10 mA?

The 2N4403_J18Z guarantees h_FE ≥ 100 at I_C = 10 mA and V_CE = 1.0 V, per its official Fairchild datasheet Rev. C. This specification enables deterministic base resistor selection for saturation - for example, a 10 kΩ base resistor delivers ~0.45 mA I_B from a 5 V logic line, ensuring ≥10× overdrive for robust turn-on across process and temperature variation.