onsemi MJF44H11

Overview

MJF44H11 from onsemi is an NPN silicon power bipolar transistor in an isolated TO-220 Fullpack package, rated for 80 V_CEO, 10 A continuous collector current, and 36 W power dissipation at T_C = 25°C, with V_CE(sat) ≤ 1.0 V at 8 A - used as a high-current switching device in DC-DC converter output stages and linear power amplifier drivers.

For engineers reviewing the MJF44H11 datasheet, pinout, applications, or equivalent options, key selection criteria include its isolated package configuration, low saturation voltage under high drive current, thermal resistance (R_JC = 3.5°C/W), safe operating area at 50% duty cycle, and complementary pairing with MJF45H11 for push-pull topologies.

Technical Context

The MJF44H11 is a medium-power NPN bipolar junction transistor optimized for switching and linear amplification in isolated-mount applications. It features a maximum V_CEO of 80 V, I_C = 10 A continuous, and operates across −55°C to +150°C junction temperature range.

Its electrical behavior is defined by h_FE ≥ 60 at I_C = 2 A and V_CE = 1 V, f_T = 50 MHz, and fast switching times (t_d + t_r ≤ 300 ns, t_f ≤ 140 ns) under specified 5 A/0.5 A drive conditions - enabling efficient operation in hard-switched SMPS and audio output stages.

Key Specifications

Pinout & Package

Package: TO-220 Fullpack (Case 221D, Style 2), isolated mounting - electrically insulated tab enables direct heatsink attachment without insulating hardware.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJF44H11G, the base part offers identical performance with standard finish; versus MJE13009, MJF44H11 delivers 33% lower conduction loss at 8 A and integrated isolation - making it superior for space-constrained, grounded-chassis 24–48 V power stages.

Availability

MJF44H11 is available at Aetrix Electronics and suitable for switching regulators, linear audio amplifiers, and DC motor drives requiring stable component supply, long-term manufacturability, and consistent parametric performance across production lots.

Supply support for MJF44H11 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, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The MJF44H11 belongs to onsemi's complementary silicon power transistor family designed for robust, high-current switching and amplification in isolated-package configurations - targeting industrial power supplies, motor controls, and audio systems demanding reliability and thermal stability.

FAQ

What is the maximum continuous collector current rating for the MJF44H11?

The MJF44H11 has a maximum continuous collector current (I_C) rating of 10 A at case temperature (T_C) = 25°C. This rating decreases linearly above 25°C at 0.288 W/°C derating - meaning at T_C = 75°C, the usable I_C drops to approximately 8.6 A. The MJF44H11 must be mounted on an adequately sized heatsink to maintain safe junction temperature under sustained load.

Does the MJF44H11 have an electrically isolated package?

Yes, the MJF44H11 uses a TO-220 Fullpack (Case 221D, Style 2) with an isolated metal tab - meaning the collector (pin 2) and mounting surface are electrically insulated from each other. This allows direct attachment to a grounded heatsink without requiring insulating hardware, simplifying thermal design and reducing parasitic capacitance in high-frequency switching applications.

What is the typical DC current gain (h_FE) of the MJF44H11 at operating conditions?

The MJF44H11 specifies h_FE ≥ 60 at V_CE = 1 V and I_C = 2 A, and ≥ 40 at V_CE = 1 V and I_C = 4 A. These values are guaranteed minimums at T_J = 25°C; actual h_FE varies with temperature and current - dropping at higher I_C and rising slightly at elevated junction temperatures per Figure 6 in the datasheet. The MJF44H11 maintains usable gain across its full operating range.

Can the MJF44H11 be used in parallel with other transistors for higher current handling?

Parallel operation of MJF44H11 devices is not recommended without individual emitter resistors and matched base drive, due to positive temperature coefficient of V_BE(sat) and potential current imbalance. While the MJF44H11 exhibits some inherent current-sharing tendency, thermal coupling and parameter spread require careful thermal management and external balancing - unlike purpose-designed paralleling transistors. For >10 A, consider higher-rated alternatives or multi-phase topologies instead of direct paralleling of MJF44H11.

What is the safe operating area (SOA) limitation for single-pulse operation of the MJF44H11?

Per Figure 2 in the datasheet, the MJF44H11 supports single-pulse operation up to 100 A at V_CE = 10 V for pulse widths ≤ 1 ms, provided junction temperature remains ≤ 150°C. The SOA boundary is defined by both thermal limits (average power) and second-breakdown limits (instantaneous power density). For reliable design, engineers must verify pulse conditions against the normalized Z_JC(t) curves in Figure 1 and ensure adequate heatsinking for repetitive pulses. The MJF44H11's SOA is validated for 50% duty cycle up to 70°C case temperature.