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Home > Products > Discrete Semiconductor Products > Transistors > Bipolar (BJT) > Single Bipolar Transistors

STMicroelectronics D44H8

Name: D44H8
Brand: STMicroelectronics
SKU: D44H8
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: D44H8

Manufacturer:: STMicroelectronics

Category:: Single Bipolar Transistors

Package:: TO-220-3

Datasheet:: D44H8.pdf

Description:: TRANS NPN 60V 10A TO-220

Quantity:: RFQ Add To RFQ list

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Inventory:1,781

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Product details

Overview

D44H8 from STMicroelectronics is an NPN silicon power bipolar junction transistor (BJT) designed for linear amplification and switching in medium-power circuits. It features 60 V V_CEO, 10 A continuous collector current, 50 W total dissipation at T_case = 25 °C, and low 1 V typical V_CE(sat) at I_C = 8 A / I_B = 0.4 A - enabling efficient operation in audio power stages and DC-DC converter switches.

For engineers reviewing the D44H8 datasheet, D44H8 pinout, D44H8 application, or D44H8 equivalent, key selection considerations include its TO-220 package thermal resistance (R_thJC = 2.5 °C/W), DC current gain (h_FE ≥ 60 at I_C = 2 A), safe operating area (SOA) limits, and complementary PNP pairing with D45H8 for push-pull output stages.

Technical Context

The D44H8 operates as a general-purpose NPN power switch or linear amplifier using multi-epitaxial planar technology, supporting both analog signal amplification and hard-switching duty cycles. Its design emphasizes low saturation voltage and fast turn-on/turn-off characteristics, with specified pulse testing conditions (≤300 µs, ≤2% duty cycle) for V_CEO(sus).

Thermal performance is defined by junction-to-case (2.5 °C/W) and junction-to-ambient (62.5 °C/W) resistances, requiring heatsinking for sustained >10 W dissipation. The device's SOA curve and derating profile govern usable voltage-current combinations across temperature and pulse width.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	60 V - maximum collector-emitter blocking voltage with base open; defines safe DC voltage swing in switching applications
I_C	10 A - continuous collector current rating; sets upper limit for steady-state load drive capability
P_TOT	50 W - total power dissipation at case temperature 25 °C; requires thermal management above ~10 W
V_CE(sat)	≤1 V at I_C = 8 A, I_B = 0.4 A - low conduction loss enables high-efficiency switching in power stages
h_FE	≥60 at I_C = 2 A, V_CE = 1 V - sufficient DC gain for direct base drive without additional pre-amplification
R_thJC	2.5 °C/W - junction-to-case thermal resistance; determines minimum heatsink requirement for given power dissipation

Pinout & Package

Package: TO-220 (Type A), through-hole, single-ended heat sink tab (pin 3). Tab is electrically connected to collector.

Pin/Terminal	Circuit Role	Design Meaning
1	Emitter	Main current return path; low-impedance connection to ground or negative rail in common-emitter configurations
2	Base	Control input; requires ~0.4 A drive current to saturate at 8 A collector load
3 (Tab)	Collector	High-current output node and primary thermal interface; must be electrically isolated from chassis unless circuit design permits

Key Features

Feature	Design Value
Low V_CE(sat)	≤1 V at full rated current - reduces conduction losses and improves efficiency in switching regulators and motor drivers
Fast switching speed	Specified via SOA and pulse test compliance - supports kHz-range switching in Class AB amplifiers and SMPS output stages
Complementary pairing	Designed for matched use with D45H8 (PNP) - enables symmetrical push-pull output stages with balanced thermal and gain characteristics
Robust SOA	Defined safe operating area up to 150 °C junction temperature - allows reliable operation under transient overload conditions

Applications

Audio Power Amplifier

DC-DC Converter Switch

Use Scenario: Output stage of 20–50 W Class AB audio amplifier driving 4–8 Ω speakers.

IC Role / Device Role / Timing Role: NPN power switch in push-pull pair; handles high-current, low-distortion analog signal amplification.

Use Value: Low V_CE(sat) minimizes crossover distortion and thermal drift; h_FE ≥ 60 ensures stable biasing without complex driver circuitry.

Use Scenario: Main switching transistor in 24 V input, 5–12 V output buck converter delivering up to 8 A.

IC Role / Device Role / Timing Role: Hard-switched power transistor controlled by PWM signal; conducts during on-time, blocks during off-time.

Use Value: 60 V V_CEO provides 2× margin over 24 V rail; 2.5 °C/W R_thJC enables compact heatsink integration for continuous 30–40 W dissipation.

Motor Drive H-Bridge Leg

Linear Voltage Regulator Pass Element

Use Scenario: High-side or low-side switch in 24 V brushed DC motor control (≤10 A peak).

IC Role / Device Role / Timing Role: Medium-power switching element in half-bridge configuration; commutates motor current direction or enables braking.

Use Value: Fast switching and SOA compliance allow PWM frequencies up to 20 kHz without secondary breakdown risk.

Use Scenario: Series pass transistor in adjustable 3–15 V, 3 A linear regulator supplying analog sensor circuitry.

IC Role / Device Role / Timing Role: Continuously biased active element dissipating excess input-output differential voltage.

Use Value: 50 W P_TOT and 150 °C T_J(max) support 12 V dropout at 3 A (36 W) with appropriate heatsinking and derating.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
TIP31C	V_CEO = 100 V, I_C = 3 A, P_TOT = 40 W - higher voltage rating but lower current and power handling	Suitable for lower-current switching where 100 V margin is critical; not recommended for >3 A continuous loads	Select when V_CEO margin >80 V is required and thermal budget permits reduced dissipation
MJE13009	V_CEO = 400 V, I_C = 12 A, P_TOT = 100 W - higher voltage and power, slower switching due to larger die	Better suited for flyback or SMPS primary switches; excessive voltage rating adds cost and capacitance for 60 V applications	Prefer for high-voltage, high-power switching; avoid in audio or low-V_CE optimized designs due to higher V_CE(sat)

Compared with TIP31C and MJE13009, the D44H8 offers optimal balance of 60 V rating, 10 A current, low saturation voltage, and TO-220 thermal performance for medium-power linear and switching tasks - making it more suitable than TIP31C for higher-current loads and more efficient than MJE13009 in 24–48 V systems.

Availability

D44H8 is available at Aetrix Electronics and suitable for audio power amplifiers, DC-DC converter switches, and motor drive H-bridge legs requiring stable component supply, consistent parametric performance, and long-term industrial availability.

Supply support for D44H8 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, specializing in power management, analog, microcontrollers, and discrete devices for industrial, automotive, and consumer markets.

The D44H8 belongs to ST's legacy power bipolar transistor family, engineered for robustness and reliability in general-purpose linear and switching applications - particularly where complementary NPN/PNP pairs and proven TO-220 thermal performance are essential.

FAQ

Is the D44H8 RoHS-compliant and lead-free?

Yes, the D44H8 is manufactured in ST's ECOPACK®-compliant TO-220 package, meeting RoHS Directive 2011/65/EU requirements. Lead-free finish is standard, and halogen-free materials are used per ST's environmental specifications. Full compliance documentation is available in ST's ECOPACK® database at www.st.com.

What is the maximum safe operating frequency for the D44H8 in switching mode?

The D44H8 does not specify a maximum switching frequency, but its SOA and pulse test conditions (≤300 µs, ≤2% duty cycle) support reliable operation up to ~20 kHz in hard-switched applications. For higher frequencies, switching losses and thermal limits require careful SOA validation and heatsink sizing per the derating curve in Figure 3.

Can the D44H8 be used without a heatsink?

No - at ambient temperatures above 25 °C or with power dissipation exceeding ~2–3 W, a heatsink is mandatory. With R_thJA = 62.5 °C/W, even 5 W dissipation raises junction temperature by >300 °C above ambient, exceeding the 150 °C absolute maximum. A minimum heatsink with R_thSA ≤ 20 °C/W is required for continuous 10 W operation.

How does the D44H8 compare to the D44H11 in terms of voltage rating and interchangeability?

The D44H11 has a higher V_CEO rating (80 V vs. 60 V) but identical package, pinout, and thermal specs. It is not a drop-in replacement in 60 V-critical designs due to different gain and saturation profiles; however, it may substitute where higher voltage margin is needed and h_FE and V_CE(sat) variations are acceptable within system tolerance.

D44H8 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-220-3

Packaging:: Tube

Product Status:: Active

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 10 A

Voltage - Collector Emitter Breakdown (Max):: 60 V

Vce Saturation (Max) @ Ib, Ic:: 1V @ 400mA, 8A

Current - Collector Cutoff (Max):: 10µA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 40 @ 4A, 1V

Power - Max:: 50 W

Frequency - Transition:: -

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220

D44H8 FAQ

1.How can I place an order for D44H8 through Aetrix?

Please submit a Request for Quotation (RFQ) for D44H8 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for D44H8 reliable?

The price and inventory of D44H8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for D44H8 is usually 5 days.

3.What payment methods are accepted for D44H8?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for D44H8 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for D44H8?

D44H8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your D44H8 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for D44H8?

For technical support, including D44H8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your D44H8 requirements.

6.How does Aetrix verify that D44H8 is sourced from the original manufacturer or authorized distributors?

All D44H8 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that D44H8 meets industry standards.

7.What is the process for return or replacement of D44H8?

All D44H8 units undergo pre-shipment inspection (PSI). If there is an issue with D44H8, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The D44H8 part is unused and in its original packaging.

Return procedure for D44H8:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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