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

Diodes Incorporated FCX1149ATA

Name: FCX1149ATA
Brand: Diodes Incorporated
SKU: FCX1149ATA
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: FCX1149ATA

Manufacturer:: Diodes Incorporated

Category:: Single Bipolar Transistors

Package:: TO-243AA

Datasheet:: FCX1149ATA.pdf

Description:: TRANS PNP 25V 3A SOT-89-3

Quantity:: RFQ Add To RFQ list

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Inventory:2,236

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Product details

Overview

FCX1149ATA from Diodes Incorporated is a 25V PNP silicon power switching transistor in SOT89 package, rated for -3A continuous collector current and -10A peak pulse current, with V_CE(sat) as low as -45mV at -0.1A/-1mA drive, optimized for high-efficiency DC-DC converter output stages and automotive load switching.

For engineers reviewing the FCX1149ATA datasheet, FCX1149ATA pinout, FCX1149ATA application, or FCX1149ATA equivalent, key selection criteria include verified PNP polarity, SOT89 thermal performance (2W on 40mm² copper), low R_sat (67mΩ), AEC-Q101 readiness, and validated -25V V_CEO rating under pulsed conditions.

Technical Context

This PNP bipolar junction transistor operates in saturation-switching mode with guaranteed V_CE(sat) ≤ -80mV at -0.1A/-1mA and ≤ -240mV at -3A/-100mA, supporting fast turn-on/turn-off (t_on = 150ns, t_off = 270ns) in high-current, low-voltage control paths. Its h_FE ranges from 115 to 800 across IC = -10mA to -10A, enabling stable gain-controlled base drive design.

Thermal performance is defined for two PCB mounting conditions: 1W dissipation on 15mm × 15mm FR4 with 1oz copper, and 2W on 40mm × 40mm - confirming suitability for thermally constrained industrial and automotive modules where SOT89 footprint is mandated.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	-25V - Maximum safe collector-emitter voltage before breakdown in open-base configuration
I_C (cont.)	-3A - Continuous DC collector current capability without derating at T_A = +25°C
V_CE(sat)	-45mV @ -0.1A/-1mA - Low conduction loss enabling <0.5W dissipation in 5V load switches
R_sat	67mΩ - Equivalent on-resistance derived from V_CE(sat)/I_C, critical for thermal budgeting
f_T	135MHz - Transition frequency confirming usable bandwidth beyond 10MHz switching
t_off	270ns - Verified turn-off delay enabling ≤3.7MHz PWM operation with margin
T_J range	-55°C to +150°C - Full automotive-grade junction temperature support per AEC-Q101 stress test alignment

Pinout & Package

Package: SOT89 - Surface-mount plastic case with exposed emitter tab for thermal conduction; 0.05g mass; UL 94V-0 rated molding compound; moisture sensitivity level 1.

Pin/Terminal	Circuit Role	Design Meaning
Collector (C)	Main current sink terminal	Connected to higher-potential rail (e.g., battery+) in high-side switch configurations
Emitter (E)	Current source terminal / thermal pad	Internally tied to metal tab; must be soldered to PCB copper pour for 2W thermal handling
Base (B)	Control input for minority-carrier injection	Requires negative current (-1mA to -140mA) to saturate; logic-level compatible with -5V drivers

Key Features

Feature	Design Value
Low V_CE(sat)	-45mV at light load enables >99% efficiency in 3.3V/5V power path switches
High I_CM	-10A peak pulse rating supports motor stall and inrush current handling without second-source substitution
SOT89 thermal design	2W power dissipation on 40mm² copper meets ASIL-B thermal safety margins for body electronics
AEC-Q101 alignment	Manufactured in IATF 16949 facilities; PPAP-capable with automotive change control process
Green compliance	Halogen- and antimony-free (<900ppm Br/Cl, <1000ppm Sb); RoHS 3 compliant with no added lead

Applications

Automotive Body Control Module

Industrial DC-DC Converter

Use Scenario: Switching 12V loads such as door locks, mirror heaters, and interior lighting in BCMs.

IC Role / Device Role / Timing Role: High-side PNP switch controlled by microcontroller GPIO with inverted logic drive.

Use Value: -25V V_CEO withstands load-dump transients; -3A rating covers dual-lamp or heater loads without parallel devices.

Use Scenario: Synchronous rectification or pre-regulator switching in isolated 24V-to-5V flyback converters.

IC Role / Device Role / Timing Role: Low-loss PNP switch in active clamp or auxiliary winding control path.

Use Value: 67mΩ R_sat reduces conduction loss below 150mW at 3A, improving full-load efficiency by ≥0.8%.

Smart Power Outlet

Medical Infusion Pump Driver

Use Scenario: Solid-state replacement for electromechanical relays controlling AC mains-powered outlets via opto-isolated DC interface.

IC Role / Device Role / Timing Role: DC-side switching element driving TRIAC gate or MOSFET level-shifter circuitry.

Use Value: 270ns t_off ensures clean commutation timing; -55°C to +150°C rating supports unventilated enclosure operation.

Use Scenario: Precision current control for stepper motor phase drivers in battery-powered infusion pumps.

IC Role / Device Role / Timing Role: Current-sinking switch in H-bridge half-bridge leg with microsecond-level timing control.

Use Value: Tight V_CE(sat) distribution (-45mV to -240mV) enables predictable thermal rise during 30-second bolus delivery cycles.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
ZTX951	V_CEO = -60V, I_C = -3A, SOT89, but V_CE(sat) = -300mV @ -1A/-10mA - 3.3× higher conduction loss	Better voltage margin but unsuitable for low-loss 5V/12V switching where FCX1149ATA's -45mV matters	Select only if system requires >-30V blocking with no thermal budget constraint
MJD2955T4G	TO-220 package, I_C = -10A, V_CEO = -60V, but 3× larger footprint and no SOT89 compatibility	Used in high-power linear regulators; incompatible with space-constrained SOT89 PCB layouts	Choose only when board area allows TO-220 and thermal mass exceeds 40mm² copper

Compared with ZTX951 and MJD2955T4G, FCX1149ATA uniquely balances ultra-low V_CE(sat), SOT89 compactness, and automotive thermal robustness - making it optimal for space- and efficiency-critical 12V/24V embedded switching where alternatives trade off size, loss, or qualification status.

Availability

FCX1149ATA is available at Aetrix Electronics and suitable for automotive body control modules, industrial DC-DC converters, smart power outlets, and medical infusion pump drivers requiring stable component supply with AEC-Q101-aligned manufacturing traceability.

Supply support for FCX1149ATA 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 manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design, manufacturing, and sales operations across Asia, Europe, and the Americas.

The FCX1149ATA belongs to Diodes' high-reliability PNP power transistor product line, engineered specifically for automotive and industrial switching applications demanding low saturation voltage, robust thermal performance in SOT89, and AEC-Q101 qualification readiness.

FAQ

What is the maximum allowable base current for FCX1149ATA?

The absolute maximum base current is -500mA per datasheet Absolute Maximum Ratings. However, for reliable saturation at I_C = -3A, the recommended base drive is -100mA (h_FE ≥ 30 at that point). Exceeding -140mA does not improve V_CE(sat) meaningfully and risks localized heating at the bond wire.

Can FCX1149ATA replace an NPN transistor in the same circuit?

No - FCX1149ATA is a PNP device requiring inverted logic and high-side switching topology. Replacing an NPN would require circuit redesign: swapping supply/reference connections, inverting control signals, and verifying bias network compatibility with PNP base-emitter forward voltage (~-0.84V).

Is FCX1149ATA qualified to AEC-Q101?

FCX1149ATA is manufactured in IATF 16949-certified facilities and supports PPAP documentation; while not explicitly listed as AEC-Q101 certified in public databases, Diodes states it meets automotive change control requirements and is intended for automotive applications - qualification testing can be initiated upon customer request.

How should the SOT89 thermal pad be connected on the PCB?

Per datasheet mechanical data, the emitter (E) terminal is internally connected to the metal tab. This tab must be soldered to a minimum 40mm² copper pour with thermal vias to inner ground/power planes. For 2W operation, use ≥6 thermal vias (0.3mm diameter) under the tab; insufficient copper area limits dissipation to 1W per note 5.

FCX1149ATA Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: -

Package/Case:: TO-243AA

Packaging:: Tape & Reel (TR)

Product Status:: Active

Transistor Type:: PNP

Current - Collector (Ic) (Max):: 3 A

Voltage - Collector Emitter Breakdown (Max):: 25 V

Vce Saturation (Max) @ Ib, Ic:: 350mV @ 140mA, 4A

Current - Collector Cutoff (Max):: 100nA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 250 @ 500mA, 2V

Power - Max:: 2 W

Frequency - Transition:: 135MHz

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-89-3

FCX1149ATA FAQ

1.How can I place an order for FCX1149ATA through Aetrix?

Please submit a Request for Quotation (RFQ) for FCX1149ATA 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 FCX1149ATA reliable?

The price and inventory of FCX1149ATA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FCX1149ATA is usually 5 days.

3.What payment methods are accepted for FCX1149ATA?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FCX1149ATA transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for FCX1149ATA?

FCX1149ATA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your FCX1149ATA 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 FCX1149ATA?

For technical support, including FCX1149ATA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FCX1149ATA requirements.

6.How does Aetrix verify that FCX1149ATA is sourced from the original manufacturer or authorized distributors?

All FCX1149ATA 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 FCX1149ATA meets industry standards.

7.What is the process for return or replacement of FCX1149ATA?

All FCX1149ATA units undergo pre-shipment inspection (PSI). If there is an issue with FCX1149ATA, 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 FCX1149ATA part is unused and in its original packaging.

Return procedure for FCX1149ATA:

1.Submit a request within 90 days.

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

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