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

STMicroelectronics D45H11

Name: D45H11
Brand: STMicroelectronics
SKU: D45H11
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: D45H11

Manufacturer:: STMicroelectronics

Category:: Single Bipolar Transistors

Package:: TO-220-3

Datasheet:: D45H11.pdf

Description:: TRANS PNP 80V 10A TO-220

Quantity:: RFQ Add To RFQ list

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Inventory:2,535

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Product details

Overview

D45H11 from STMicroelectronics is a PNP silicon power bipolar junction transistor (BJT) designed for linear amplification and high-current switching in industrial power stages. It features 80 V V_CEO, 10 A continuous collector current, 50 W total dissipation at T_case = 25 °C, and low 1 V V_CE(sat) at I_C = 8 A / I_B = 0.4 A - enabling efficient operation in audio output stages and DC motor drivers.

For engineers reviewing the D45H11 datasheet, D45H11 pinout, D45H11 application, or D45H11 equivalent, key selection criteria include its TO-220 package thermal performance (R_thJC = 2.5 °C/W), complementary pairing with D44H11, PNP polarity, and suitability for Class AB amplifier output stages requiring stable h_FE ≥ 40 at I_C = 4 A.

Technical Context

The D45H11 operates as a medium-power PNP BJT using multi-epitaxial planar technology, optimized for both linear (e.g., analog power amplification) and switching (e.g., relay/actuator control) modes. Its safe operating area (SOA) supports pulsed I_C up to 20 A, and its derating curve specifies linear thermal roll-off beyond 25 °C case temperature.

Designed for complementary use with NPN D44H11, it shares identical TO-220 mechanical dimensions and thermal resistance values (R_thJC = 2.5 °C/W, R_thJA = 62.5 °C/W), enabling matched thermal tracking in push-pull configurations. Base-emitter saturation voltage is specified at –1.5 V (I_C = 8 A, I_B = 0.8 A), confirming robust drive capability under heavy load.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	80 V - Maximum collector-emitter blocking voltage with base open; defines maximum supply rail compatibility in switching applications.
I_C	10 A - Continuous DC collector current rating; determines sustained load-handling capacity in power amplifier output stages.
V_CE(sat)	1 V @ I_C = 8 A, I_B = 0.4 A - Low saturation voltage minimizes conduction loss and heat generation during switching.
h_FE	≥40 @ I_C = 4 A, V_CE = 1 V - Sufficient DC current gain for direct base drive in medium-speed switching circuits without Darlington buffering.
R_thJC	2.5 °C/W - Junction-to-case thermal resistance enables effective heatsink coupling; allows ~20 W dissipation before reaching 150 °C junction limit at 25 °C case.
P_TOT	50 W @ T_case = 25 °C - Total power dissipation limit; sets upper bound for combined conduction and switching losses in thermally managed designs.

Pinout & Package

Supplied in TO-220 package (Type A), with metal tab electrically connected to collector (Pin 2). Standard three-terminal configuration supports through-hole mounting and direct heatsinking via tab screw.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Emitting terminal for majority carriers (holes)	Connected to higher potential rail in PNP switch; source of current flow into load.
2 (Collector / Tab)	Main current-collecting terminal and thermal path	Electrically tied to metal tab; must be isolated from chassis unless circuit ground reference permits.
3 (Base)	Control electrode for minority carrier injection	Receives negative-going drive signal relative to emitter to turn on; requires ~0.4 A for full saturation at 8 A load.

Key Features

Feature	Design Value
Low V_CE(sat)	1 V at 8 A ensures ≤8 W conduction loss per device in Class AB output stage, reducing heatsink requirements.
Fast switching speed	Supported by low stored charge and optimized epitaxial structure; enables clean turn-off in PWM-driven motor controls up to ~100 kHz.
Complementary pairing	Matched specs with D44H11 (NPN) allow symmetrical push-pull amplifier design with balanced thermal and gain characteristics.
Robust SOA	Rated for 20 A peak collector current with defined pulse conditions; accommodates inductive kickback in relay and solenoid drivers.

Applications

Audio Power Amplifier

DC Motor Driver

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

IC Role / Device Role / Timing Role: PNP output transistor delivering negative half-cycle current; paired with D44H11 for full-wave amplification.

Use Value: Low V_CE(sat) and stable h_FE minimize crossover distortion and thermal drift across audio bandwidth.

Use Scenario: H-bridge low-side switch controlling bidirectional 12–24 V DC motors in industrial actuators.

IC Role / Device Role / Timing Role: High-current PNP switch sinking motor current during reverse-phase conduction.

Use Value: 80 V V_CEO withstands back-EMF spikes; fast switching reduces switching losses in 20 kHz PWM operation.

Relay Driver

Linear Voltage Regulator Pass Element

Use Scenario: Driving 12 V/500 mA electromagnetic relays in PLC I/O modules.

IC Role / Device Role / Timing Role: Saturated PNP switch interfacing microcontroller GPIO to relay coil.

Use Value: 10 A I_C rating provides 20× safety margin; low V_CE(sat) limits coil voltage drop to <0.5 V at rated load.

Use Scenario: Series pass element in adjustable 3–15 V, 3 A linear regulator for test equipment power supplies.

IC Role / Device Role / Timing Role: PNP pass transistor regulating output by modulating emitter-base voltage.

Use Value: 50 W P_TOT and 2.5 °C/W R_thJC support 12 W dissipation at 75 °C case, enabling reliable 3 A output at 10 V dropout.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MJD45H11T4	Surface-mount DPAK package; same V_CEO, I_C, and h_FE; R_thJC = 3.0 °C/W (slightly higher thermal resistance).	Requires PCB layout change; unsuitable for through-hole prototyping or legacy TO-220 heatsinks.	Select when automated assembly and space-constrained board design are priorities over manual serviceability.
BD711	Lower V_CEO = 60 V; same I_C = 10 A; h_FE min = 25 (vs. 40); R_thJC = 3.5 °C/W.	Limited to ≤48 V systems; reduced gain demands higher base drive current for equivalent saturation.	Acceptable only in cost-sensitive, lower-voltage applications where 80 V margin is unnecessary.

Compared with MJD45H11T4 and BD711, D45H11 offers superior thermal performance (2.5 °C/W), guaranteed 80 V blocking, and higher minimum h_FE, making it optimal for thermally demanding, high-reliability linear and switching power stages where TO-220 mounting is preferred.

Availability

D45H11 is available at Aetrix Electronics and suitable for audio power amplifiers, DC motor drivers, relay interface circuits, and linear voltage regulator pass elements requiring stable component supply and long-term industrial availability.

Supply support for D45H11 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 analog, digital, and mixed-signal ICs and discrete devices for automotive, industrial, and consumer markets.

The D45H11 belongs to ST's legacy power bipolar transistor family, engineered specifically for robust, cost-effective linear amplification and medium-speed switching in industrial power conversion and control systems.

FAQ

Is D45H11 pin-compatible with D44H11?

No - D45H11 is PNP and D44H11 is NPN, so their pinouts are complementary, not identical. Both use TO-220 with emitter-base-collector (E-B-C) pin order, but polarity reversal means they cannot substitute directly without circuit redesign. They are intended for paired use in push-pull topologies, not interchange.

What is the maximum safe operating frequency for D45H11 in switching mode?

D45H11 is characterized for fast switching but lacks published f_T or switching time specs in its datasheet. Practical use is limited to ≤100 kHz in hard-switched applications due to stored charge and minority carrier lifetime. For >200 kHz operation, MOSFETs or RF-optimized BJTs are recommended.

Can D45H11 be used without a heatsink?

Only at very low duty cycles and ambient temperatures ≤25 °C with <1 W dissipation. At full 10 A I_C, even brief saturation generates >8 W - exceeding its 50 W rating only if case temperature remains at 25 °C. A minimum 2.5 °C/W heatsink is required for sustained operation above 2 W.

Does D45H11 meet RoHS and REACH requirements?

Yes - per ST's ECOPACK® documentation referenced in the datasheet, D45H11 is offered in RoHS-compliant versions (Pb-free, halogen-free) with full REACH SVHC declaration. The "ECOPACK®" marking on packaging confirms compliance with EU environmental directives.

D45H11 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-220-3

Packaging:: Tube

Product Status:: Active

Transistor Type:: PNP

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

Voltage - Collector Emitter Breakdown (Max):: 80 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

D45H11 FAQ

1.How can I place an order for D45H11 through Aetrix?

Please submit a Request for Quotation (RFQ) for D45H11 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 D45H11 reliable?

The price and inventory of D45H11 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for D45H11 is usually 5 days.

3.What payment methods are accepted for D45H11?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for D45H11 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for D45H11?

D45H11 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your D45H11 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 D45H11?

For technical support, including D45H11 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your D45H11 requirements.

6.How does Aetrix verify that D45H11 is sourced from the original manufacturer or authorized distributors?

All D45H11 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 D45H11 meets industry standards.

7.What is the process for return or replacement of D45H11?

All D45H11 units undergo pre-shipment inspection (PSI). If there is an issue with D45H11, 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 D45H11 part is unused and in its original packaging.

Return procedure for D45H11:

1.Submit a request within 90 days.

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

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