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

Diodes Incorporated FZT855QTC

Name: FZT855QTC
Brand: Diodes Incorporated
SKU: FZT855QTC
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: FZT855QTC

Manufacturer:: Diodes Incorporated

Category:: Single Bipolar Transistors

Package:: TO-261-4, TO-261AA

Datasheet:: FZT855QTC.pdf

Description:: TRANS NPN 150V 5A SOT-223-3

Quantity:: RFQ Add To RFQ list

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Inventory:4,417

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Product details

Overview

FZT855QTC from Diodes Incorporated is a 150V NPN high-voltage transistor in SOT223 package, rated for 5A continuous collector current and 10A peak pulse current, with V_CE(sat) < 110mV at 1A and R_CE(sat) = 50mΩ, used in automotive power switching, DC-DC converter primary-side switching, and industrial relay drivers.

For engineers reviewing the FZT855QTC datasheet, FZT855QTC pinout, FZT855QTC application, or FZT855QTC equivalent, key selection criteria include high-voltage blocking (V_CEO = 150V), low on-resistance operation, AEC-Q101 qualification, thermal resistance (R_θJA = 42°C/W on 52mm × 52mm PCB), and SOT223 surface-mount compatibility with high-current PCB layout.

Technical Context

This NPN bipolar junction transistor operates as a high-voltage, medium-power switch with specified h_FE up to 10A (min 10 at I_C = 10A), enabling stable gain hold-up under heavy load transients. Its BVCBO = 250V and BVCEO = 150V support robust isolation in flyback and boost topologies.

Designed for pulsed switching applications, it delivers f_T = 90MHz at V_CE = 10V and I_C = 100mA, with fast turn-on/turn-off times (t_on = 66ns, t_off = 2130ns) under I_B1 = −I_B2 = 100mA, suitable for PWM-controlled power stages up to ~100kHz.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	150V - supports 125V rail designs with 20% margin for voltage spikes in automotive and industrial supplies
I_C (continuous)	5A - enables direct drive of solenoids, fans, or MOSFET gate drivers without external buffering
V_CE(sat) @ 1A	<110mV - reduces conduction loss to <110mW at 1A, critical for thermally constrained SOT223 layouts
R_CE(sat)	50mΩ - provides predictable on-state resistance for current-sense accuracy in linear-regulator bypass paths
h_FE @ 10A	Min 10 - ensures reliable saturation with base drive ≤500mA, simplifying driver IC selection
f_T	90MHz - supports high-speed switching in resonant converters and active clamp circuits
R_θJA	42°C/W - requires ≥52mm × 52mm 2oz copper pad for full 3W dissipation at +25°C ambient

Pinout & Package

Package: SOT223 - surface-mount plastic package with integrated heat slug (collector tab), UL 94V-0 rated, moisture sensitivity level 1, 0.112g mass.

Pin/Terminal	Circuit Role	Design Meaning
Emitter (E)	Current return path	Low-impedance connection to ground or low-side reference; soldered to large copper pour for thermal relief
Base (B)	Control input	Receives current-limited drive (max 1A) to saturate transistor; requires series resistor for TTL/CMOS interface
Collector (C)	High-voltage switched output	Connected to heat slug and PCB thermal pad; carries full load current and must be routed with clearance for 150V working voltage

Key Features

Feature	Design Value
AEC-Q101 qualified	Validated for automotive power modules requiring PPAP documentation and IATF16949 manufacturing
V_CE(sat) < 110mV @ 1A	Enables >98% efficiency in 12V/5A switching loads with minimal heatsinking in SOT223
h_FE specified up to 10A	Guarantees saturation with standard 500mA base drive, eliminating need for Darlington staging
R_CE(sat) = 50mΩ	Supports accurate current monitoring via Kelvin-sense emitter resistors in feedback loops
Lead-free, halogen-free "Green" construction	Complies with RoHS 3 (2015/863/EU) and JEDEC J-STD-020 Level 1 moisture handling

Applications

Automotive HVAC Blower Control

Industrial PLC Output Stage

Use Scenario: PWM-driven 24V blower motor in passenger cabin climate systems, operating continuously at 3–5A with thermal cycling.

IC Role / Device Role / Timing Role: High-side NPN switch controlling motor current path, driven by microcontroller GPIO through base resistor.

Use Value: Low V_CE(sat) minimizes self-heating during 100% duty cycle; AEC-Q101 qualification ensures reliability across −40°C to +125°C ambient.

Use Scenario: 24V DC solid-state output module driving electromagnetic valves and indicator lamps in factory automation cabinets.

IC Role / Device Role / Timing Role: Medium-power discrete switch replacing mechanical relays, interfaced with optocoupled controller signals.

Use Value: 150V V_CEO withstands inductive kickback from 24V solenoids; SOT223 thermal pad enables conduction cooling without heatsink.

DC-DC Converter Primary Switch

LED Driver for High-Bay Lighting

Use Scenario: 48V input, 350kHz flyback converter supplying isolated 12V/3A for vehicle infotainment subsystems.

IC Role / Device Role / Timing Role: Primary-side switching transistor in self-oscillating or PWM-controlled topology, dissipating <1.5W average power.

Use Value: 90MHz f_T supports clean switching edge integrity; R_θJA = 42°C/W allows operation at 75°C case temperature with standard PCB layout.

Use Scenario: Constant-current LED string driver for 100W industrial high-bay fixtures, using linear current regulation with shunt control.

IC Role / Device Role / Timing Role: Precision current-regulating pass element, biased in linear region with feedback from sense resistor.

Use Value: Stable h_FE up to 10A ensures consistent current gain across temperature; low V_BE(sat) improves regulation accuracy at high currents.

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN high-voltage transistor applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
ZXTN25050DFH	V_CEO = 50V, I_C = 5A, SOT23 package, lower voltage rating and smaller thermal mass	Suitable only for ≤36V systems; not AEC-Q101 qualified	Select only for space-constrained, low-voltage consumer applications where 150V margin is unnecessary
MJD122G	V_CEO = 100V, I_C = 8A, TO-220 package, higher current but lower voltage rating and no automotive qualification	Requires heatsink; incompatible with SMT-only assembly; lacks PPAP support	Prefer for non-automotive industrial use where board space permits TO-220 and 100V blocking suffices

Compared with ZXTN25050DFH and MJD122G, FZT855QTC uniquely combines 150V blocking, SOT223 surface-mount compatibility, AEC-Q101 qualification, and guaranteed h_FE at 10A-making it the only option for automotive-grade, high-voltage, medium-current SMT switching where thermal and qualification constraints overlap.

Availability

FZT855QTC is available at Aetrix Electronics and suitable for automotive HVAC control, industrial PLC outputs, and DC-DC converter primary-side switching requiring stable component supply, long-term lifecycle assurance, and AEC-Q101-compliant sourcing.

Supply support for FZT855QTC 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

Diodes Incorporated is a global semiconductor company specializing in discrete, analog, and mixed-signal solutions, with design, manufacturing, and test facilities certified to IATF16949 and ISO9001 standards.

The FZT855QTC belongs to Diodes' high-voltage bipolar transistor product line, engineered specifically for automotive and industrial power switching applications demanding robust voltage tolerance, thermal stability, and AEC-Q101 compliance in compact SMT packages.

FAQ

What is the maximum allowable junction temperature for FZT855QTC?

The FZT855QTC has an operating junction temperature range of −55°C to +150°C. Its absolute maximum T_J is +150°C, and sustained operation above this threshold risks permanent degradation. Derating begins at +25°C ambient per the 24mW/°C linear factor when mounted on a 52mm × 52mm 2oz copper PCB.

Is FZT855QTC suitable for linear (analog) operation, or only switching?

FZT855QTC is characterized and qualified for both switching and linear operation. Its h_FE specification up to 10A and low V_CE(sat) support stable biasing in constant-current regulator circuits, though power dissipation must remain within PD = 3.0W (derated above +25°C) and thermal design must accommodate R_θJA = 42°C/W.

Does FZT855QTC require a heatsink in typical SOT223 PCB layouts?

No external heatsink is required if the SOT223 footprint includes a minimum 52mm × 52mm single-sided 2oz copper thermal pad connected to the collector tab. Under those conditions, the device sustains 3.0W at +25°C ambient. Smaller pads (e.g., 25mm × 25mm 1oz copper) reduce PD to 1.6W and increase R_θJA to 78°C/W, potentially necessitating derating or airflow.

How does the AEC-Q101 qualification impact FZT855QTC's use in non-automotive applications?

AEC-Q101 qualification confirms rigorous stress testing (HTOL, TC, UHAST, etc.) and process controls under IATF16949, making FZT855QTC highly reliable for any mission-critical industrial or medical application-even outside automotive. It does not restrict usage; rather, it provides documented confidence in long-term parametric stability and failure-rate performance under thermal and electrical stress.

FZT855QTC Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: -

Package/Case:: TO-261-4, TO-261AA

Packaging:: Tape & Reel (TR)

Product Status:: Active

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 5 A

Voltage - Collector Emitter Breakdown (Max):: 150 V

Vce Saturation (Max) @ Ib, Ic:: 355mV @ 500mA, 5A

Current - Collector Cutoff (Max):: 50nA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 100 @ 1A, 5V

Power - Max:: 1.6 W

Frequency - Transition:: 90MHz

Operating Temperature:: -55°C ~ 150°C (TJ)

Grade:: Automotive

Qualification:: AEC-Q101

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-223-3

FZT855QTC FAQ

1.How can I place an order for FZT855QTC through Aetrix?

Please submit a Request for Quotation (RFQ) for FZT855QTC 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 FZT855QTC reliable?

The price and inventory of FZT855QTC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FZT855QTC is usually 5 days.

3.What payment methods are accepted for FZT855QTC?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FZT855QTC transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for FZT855QTC?

FZT855QTC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your FZT855QTC 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 FZT855QTC?

For technical support, including FZT855QTC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FZT855QTC requirements.

6.How does Aetrix verify that FZT855QTC is sourced from the original manufacturer or authorized distributors?

All FZT855QTC 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 FZT855QTC meets industry standards.

7.What is the process for return or replacement of FZT855QTC?

All FZT855QTC units undergo pre-shipment inspection (PSI). If there is an issue with FZT855QTC, 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 FZT855QTC part is unused and in its original packaging.

Return procedure for FZT855QTC:

1.Submit a request within 90 days.

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

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