onsemi 2N4402TA

Overview

2N4402TA from ON Semiconductor (formerly Fairchild) is a PNP bipolar junction transistor designed for general-purpose amplification and switching in low-to-medium power circuits, with confirmed V_CEO = 40 V, I_C = 600 mA continuous, h_FE ≥ 30 at I_C = 1.0 mA, and TO-92 package. It operates across –55 °C to +150 °C and supports switching applications up to 500 mA collector current.

For engineers reviewing the 2N4402TA datasheet, pinout, applications, or equivalent options, key selection criteria include verified PNP polarity, saturation voltage ≤ 0.75 V at I_C = 500 mA / I_B = 50 mA, thermal resistance R_θJA = 200 °C/W, and suitability for discrete amplifier stages or logic-level interface switches.

Technical Context

The 2N4402TA functions as a medium-current PNP BJT with fixed gain structure-h_FE ranges from 30 to 150 depending on operating point-and exhibits well-characterized saturation behavior (V_CE(sat) ≤ 0.75 V, V_BE(sat) ≤ 0.95 V at high drive). Its small-signal parameters include h_fe = 30–250 (f = 100 MHz), C_ob = 8.5 pF, and C_ib = 30 pF, supporting stable operation in audio-frequency amplifiers and digital switching.

Thermal design is constrained by R_θJA = 200 °C/W and P_D = 625 mW at T_A = 25 °C, derating linearly at 5.0 mW/°C above ambient. Switching performance is documented with t_d = 15 ns, t_r = 20 ns, t_s = 225 ns, and t_f = 30 ns under pulsed test conditions (≤300 µs, ≤2% duty cycle).

Key Specifications

Pinout & Package

2N4402TA is housed in a through-hole TO-92 package (3-lead, epoxy molded, JEDEC TO-92 variant), with standardized lead orientation: Emitter (E), Base (B), Collector (C) - left-to-right when flat side faces viewer and leads point 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 BC557B, the 2N4402TA uniquely balances 40 V breakdown, 600 mA current handling, and sub-0.75 V saturation-making it optimal for cost-sensitive, medium-power PNP switching where both voltage margin and current drive matter.

Availability

2N4402TA is available at Aetrix Electronics and suitable for relay drivers, discrete logic inverters, linear audio preamplifiers, and overcurrent protection sensing nodes requiring stable component supply and long-term industrial availability.

Supply support for 2N4402TA 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 is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, communications, computing, and consumer electronics.

The 2N4402TA belongs to ON Semiconductor's legacy general-purpose bipolar transistor product line, engineered for robust, low-cost discrete switching and amplification in non-automotive industrial and consumer systems.

FAQ

What is the maximum continuous collector current rating for the 2N4402TA?

The 2N4402TA has a maximum continuous collector current (I_C) rating of 600 mA at T_A = 25 °C. This value is confirmed in the Absolute Maximum Ratings table. Operation at 500 mA is fully validated with published saturation characteristics (V_CE(sat), V_BE(sat)) and switching times. Sustained operation above 300 mA requires attention to thermal derating per the 5.0 mW/°C specification.

Is the 2N4402TA pin-compatible with other TO-92 PNP transistors like the BC557 or MPSA92?

The 2N4402TA uses standard TO-92 pinout (E-B-C, left-to-right, flat side facing viewer), matching BC557 and MPSA92 mechanically. However, electrical compatibility is not guaranteed: BC557 is rated only to 100 mA, and MPSA92 has 300 V V_CEO but different h_FE distribution. The 2N4402TA must be evaluated per circuit requirements-not assumed drop-in.

What is the typical V_CE(sat) of the 2N4402TA under switching conditions?

The 2N4402TA specifies V_CE(sat) = 0.40 V at I_C = 150 mA / I_B = 15 mA and 0.75 V at I_C = 500 mA / I_B = 50 mA. These values are measured under pulsed conditions and represent worst-case saturation voltage for design margining. At 200 mA, typical V_CE(sat) is ~0.5 V, enabling efficient low-loss switching in relay and LED driver applications.

Does the 2N4402TA support operation at elevated ambient temperatures?

Yes-the 2N4402TA is rated for T_A = –55 °C to +150 °C, with junction temperature limited to +150 °C. At 100 °C ambient, its power dissipation must be derated to ~250 mW (625 mW – 75 °C × 5.0 mW/°C). Thermal resistance R_θJA = 200 °C/W confirms suitability for sealed enclosures or board-level thermal management without forced air.

Can the 2N4402TA be used in small-signal amplifier configurations?

Yes-the 2N4402TA provides h_fe = 30–250 at f = 100 MHz and I_C = 1–20 mA, with input impedance h_ie = 0.75–7.5 kΩ and output admittance h_oe = 1–100 µmhos. Its Cob = 8.5 pF and Cib = 30 pF support stable gain up to 20 kHz in common-emitter audio preamps. Bias stability is enhanced by low I_CEX ≤ 0.1 µA at V_CE = 35 V.