onsemi MJL0281AG

Overview

MJL0281AG from onsemi is an NPN complementary silicon power bipolar transistor in TO-264 (Case 340G) package, rated for 15 A continuous collector current, 260 V V_CEO, and 180 W power dissipation at T_C = 25°C. It delivers exceptional safe operating area (SOA), gain linearity up to 3.0 A, and 30 MHz f_T, making it suitable for high-fidelity audio amplifier output stages.

For engineers reviewing the MJL0281AG datasheet, pinout, applications, or equivalent options, key selection considerations include SOA robustness at high V_CE, h_FE matching with MJL0302AG in push-pull configurations, thermal resistance (R_θJC = 0.69°C/W), and Pb-free compliance for industrial audio designs.

Technical Context

The MJL0281AG is a discrete NPN power bipolar transistor optimized for linear operation in Class AB audio output stages. Its design emphasizes symmetrical gain matching (±10% with MJL0302A across 50 mA–3.0 A), high BV_CEO (260 V), and wide SOA - enabling stable operation under reactive loads without secondary breakdown.

It features high-frequency capability (f_T = 30 MHz at I_C = 1.0 A, V_CE = 5 V), low saturation voltage (V_CE(sat) ≤ 1.0 V at I_C = 5.0 A, I_B = 0.5 A), and temperature-stable h_FE characteristics validated from −25°C to +100°C - critical for thermal tracking in dual-rail amplifiers.

Key Specifications

Pinout & Package

Package: TO-264 (Case 340G), Pb-free, isolated metal tab, 3-terminal through-hole power package with mechanical outline per Issue J (17 DEC 2004).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar power bipolar transistor applications.

Compared with MJL0281A, the MJL0281AG offers identical performance with mandatory Pb-free compliance; versus MJL3281A, it provides tighter gain matching, lower thermal mass, and optimized SOA for mainstream high-fidelity audio - not raw power headroom.

Availability

MJL0281AG is available at Aetrix Electronics and suitable for high-end consumer audio products, professional public address systems, and theater sound systems requiring stable component supply, long-term manufacturability, and RoHS-compliant sourcing.

Supply support for MJL0281AG 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The MJL0281AG belongs to onsemi's Power Bipolar Transistor family, engineered specifically for high-linearity, high-reliability audio output stages where SOA integrity, gain symmetry, and thermal stability are primary design constraints.

FAQ

What is the maximum continuous collector current rating for the MJL0281AG?

The MJL0281AG is rated for 15 A continuous collector current (I_C) at case temperature T_C = 25°C. Derating is required above 25°C per Figure 1 in the datasheet - e.g., ~12 A at T_C = 75°C. This rating assumes adequate heatsinking to maintain junction temperature below 150°C under steady-state conditions. The MJL0281AG must be mounted with thermal compound and mechanical torque per TO-264 specifications to achieve full current capability.

Is the MJL0281AG pin-compatible with the MJL0302AG?

Yes, the MJL0281AG (NPN) and MJL0302AG (PNP) share identical TO-264 package dimensions, pinout (Base–Collector–Emitter), and mounting footprint. They are designed as complementary pairs for push-pull output stages, with matched h_FE and SOA characteristics. The MJL0281AG and MJL0302AG may be used together on the same heatsink without layout modification, provided polarity-aware routing is maintained.

What is the safe operating area (SOA) limit of the MJL0281AG at 100 V V_CE?

Per Figure 2 in the official datasheet, the MJL0281AG supports up to 10 A DC collector current at V_CE = 100 V with no second breakdown risk. At higher V_CE, SOA narrows - e.g., 5 A at 200 V. This DC SOA curve is validated for pulse widths ≥100 ms and reflects ruggedness against sustained reactive loads in audio amplifiers. The MJL0281AG's SOA exceeds that of many legacy power transistors, enabling reliable operation without external SOA protection circuits.

Does the MJL0281AG require a minimum base drive current to operate linearly?

Yes - for linear Class AB operation, the MJL0281AG requires sufficient base drive to maintain h_FE in its specified range (75–150). At I_C = 3.0 A, typical I_B is 20–40 mA. Driving below this risks entering quasi-saturation, increasing distortion and V_CE(sat). The MJL0281AG's base-emitter on voltage (V_BE(on) ≤ 1.2 V at I_C = 5.0 A) informs driver stage design; insufficient drive degrades linearity and thermal stability in the MJL0281AG.

How does the thermal resistance of the MJL0281AG affect heatsink selection?

The MJL0281AG has a junction-to-case thermal resistance (R_θJC) of 0.69°C/W. To keep T_J ≤ 130°C at 180 W dissipation, the total thermal path (case-to-heatsink + heatsink-to-ambient) must limit R_θCA to ≤0.64°C/W. This demands high-performance heatsinks with forced air or large surface area - e.g., ≥0.3°C/W R_θHA with thermal interface material ≤0.05°C/W. Proper mounting pressure and flatness are critical to realize the MJL0281AG's rated R_θJC.