STMicroelectronics D44H11FP

Overview

D44H11FP from STMicroelectronics is an NPN bipolar junction transistor (BJT) designed for linear amplification and high-current switching in complementary power stages. It features 80 V V_CEO, 10 A continuous collector current, 36 W total power dissipation at T_case = 25 °C, and low 1 V V_CE(sat) at I_C = 8 A / I_B = 0.4 A - used in audio power amplifier output stages and DC-DC converter switches.

For engineers reviewing the D44H11FP datasheet, D44H11FP pinout, D44H11FP application, or D44H11FP equivalent, key selection criteria include V_CEO rating, saturation voltage under high I_C, thermal resistance (R_thJC = 3.5 °C/W), h_FE linearity at 2–4 A, and TO-220FP package isolation for heatsink mounting.

Technical Context

This NPN transistor uses multi-epitaxial planar technology to achieve stable h_FE across 2–4 A collector current and low V_CE(sat) at high drive levels. Its fully isolated TO-220FP package enables direct heatsink mounting without insulating washers while maintaining electrical separation between collector and case.

The device operates with a maximum junction temperature of 150 °C and supports fast switching via low stored charge and optimized base-emitter doping. It forms a complementary pair with D45H11FP (PNP), enabling push-pull configurations in Class AB amplifiers and half-bridge topologies.

Key Specifications

Pinout & Package

Supplied in a fully isolated TO-220FP package with metal tab electrically isolated from the collector terminal. The package enables direct mechanical attachment to heatsinks without thermal pads or insulators while maintaining electrical safety.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJD44H11T4 and TIP41C, D44H11FP offers superior thermal performance (R_thJC = 3.5 °C/W), full collector-to-case isolation, and higher voltage headroom - making it optimal for high-reliability, high-power linear and switching applications requiring robust heatsinking.

Availability

D44H11FP is available at Aetrix Electronics and suitable for audio power amplifiers, DC-DC converters, motor drive half-bridges, and industrial linear regulators requiring stable component supply and long-term manufacturability.

Supply support for D44H11FP 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power transistors, sensors, and analog ICs for industrial, automotive, and consumer markets.

D44H11FP belongs to ST's legacy power bipolar transistor family, engineered specifically for high-fidelity audio output stages and robust industrial switching applications where reliability, thermal performance, and complementary pairing are critical.

FAQ

Is D44H11FP pin-compatible with D44H11?

No. D44H11FP uses a fully isolated TO-220FP package where the metal tab is electrically isolated from the collector, whereas standard D44H11 in TO-220 has the collector internally bonded to the tab. This isolation eliminates the need for insulating hardware but changes mechanical mounting behavior and thermal interface design.

What is the maximum safe continuous collector current at 70 °C case temperature?

At T_case = 70 °C, derating applies: 36 W max dissipation × (150 − 70) °C / (150 − 25) °C = ~22.1 W. With V_CE(sat) ≈ 1 V, maximum continuous I_C ≈ 22 A × (22.1 W / 36 W) ≈ 13.6 A - but absolute I_C rating remains 10 A per datasheet, limiting practical use to 10 A regardless of thermal headroom.

Can D44H11FP be used in avalanche mode?

No. D44H11FP is not rated for avalanche energy absorption. Its V_CEO(sus) = 80 V is specified under pulsed conditions (≤300 µs, ≤2% duty cycle), but no EAS (avalanche energy) rating is provided. Operation beyond V_CEO risks irreversible junction failure.

Does D44H11FP require a base resistor in switching applications?

Yes. To achieve full saturation at I_C = 8 A, I_B ≥ 0.4 A is required. A series base resistor must limit driver current accordingly - e.g., with 5 V logic drive and 0.8 V V_BE(sat), R_B ≈ (5 − 0.8) V / 0.4 A = 10.5 Ω - and must handle ≥0.5 W peak power.