onsemi D44H11

Overview

D44H11 from onsemi is an NPN silicon power transistor designed for high-current switching and linear amplification in power stages. It delivers 80 V_CEO, 10 A continuous collector current, 1.0 V_CE(sat) at 8 A/0.4 A drive, and operates across −55°C to +150°C junction temperature - enabling use in DC-DC converter output stages, motor driver H-bridge legs, and industrial power supply regulators.

For engineers reviewing the D44H11 datasheet, pinout, applications, or equivalent options, key selection criteria include verified V_CEO = 80 V, h_FE ≥ 40 at 4 A, R_JC = 1.8 °C/W thermal resistance, TO-220 package mechanical compatibility, and Pb-free RoHS-compliant construction per onsemi's 2021 Rev. 14 specification.

Technical Context

The D44H11 operates as a medium-power NPN bipolar junction transistor optimized for saturated switching and analog amplification. Its design emphasizes low V_CE(sat) (≤1.0 V) and fast switching (t_d+t_r ≤ 300 ns, t_f ≤ 140 ns), with f_T = 50 MHz enabling stable gain in audio and SMPS feedback paths.

It forms complementary pairs with D45H11 (PNP), sharing identical TO-220 package footprint and thermal characteristics (R_JA = 62.5 °C/W, R_JC = 1.8 °C/W), allowing matched push-pull stage implementation without layout redesign.

Key Specifications

Pinout & Package

Package: TO-220 (Case 221A, Style 1), plastic, Pb-free, with collector connected to tab for direct heatsinking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJD44H11T4G and TIP31C, the D44H11 provides superior thermal management (R_JC = 1.8 °C/W), tighter h_FE min spec (≥40), and proven 80 V/10 A capability - making it optimal for industrial-grade switching where reliability and thermal headroom are critical.

Availability

D44H11 is available at Aetrix Electronics and suitable for DC-DC converters, motor drivers, linear amplifiers, and lab power supplies requiring stable component supply across extended production lifecycles.

Supply support for D44H11 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 focused on energy-efficient electronics, with leadership in power management, analog, and discrete devices.

The D44H series belongs to onsemi's complementary silicon power transistor product line, engineered specifically for robust, thermally efficient switching and amplification in industrial power conversion and motor control systems.

FAQ

What is the maximum continuous collector current rating for D44H11?

The D44H11 has a maximum continuous collector current (I_C) rating of 10 A at T_C = 25°C. This rating assumes proper heatsinking - derating applies above 25°C case temperature per the power derating curve in Figure 10. At T_C = 100°C, usable I_C drops to approximately 4.5 A. The D44H11 datasheet specifies this limit under steady-state conditions with adequate thermal management.

Is D44H11 pin-compatible with D44H8?

Yes, the D44H11 is pin-compatible with D44H8 - both use identical TO-220 (Case 221A) packaging and share the same 1-Base / 2&4-Collector / 3-Emitter pinout. However, D44H11 offers higher V_CEO (80 V vs. 60 V) and slightly lower h_FE minimum (40 vs. 60 at 2 A), so system-level voltage margin and gain stability must be re-verified when substituting.

Does D44H11 require a heatsink in typical 5 A switching applications?

Yes, the D44H11 requires a heatsink in typical 5 A switching applications. With R_JC = 1.8 °C/W and typical V_CE(sat) ≈ 0.8 V at 5 A, conduction loss is ~4 W - raising junction temperature by >7°C above case even before ambient contribution. Without a heatsink, case temperature rises rapidly; a modest 10 °C/W heatsink keeps T_J within safe limits for continuous operation.

What is the safe operating area (SOA) limitation for D44H11 at 100 µs pulse width?

Per Figure 9 in the D44H11 datasheet, the SOA limit at 100 µs pulse width is approximately 8 A at 40 V_CE. This reflects second breakdown constraints - exceeding this boundary risks localized thermal runaway. For 100 µs pulses, peak I_C must be reduced as V_CE increases; at 60 V, the limit drops to ~4.5 A. Always reference the SOA curve, not just DC ratings, for pulsed designs.

How does D44H11 compare to D45H11 in terms of complementary pairing?

The D44H11 (NPN) and D45H11 (PNP) are engineered as matched complementary pairs: identical TO-220 package, same R_JC (1.8 °C/W), overlapping V_CEO (80 V), and closely aligned switching times (D44H11 t_f = 140 ns, D45H11 t_f = 100 ns). This matching simplifies symmetric push-pull and H-bridge design, minimizing cross-conduction risk and thermal imbalance in dual-transistor stages.