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Diodes Incorporated FCX491QTA
- Part No.:
- FCX491QTA
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Bipolar Transistors
- Package:
- TO-243AA
- Datasheet:
-
FCX491QTA.pdf
- Description:
- TRANS NPN 60V 1A SOT-89-3
- Quantity:
- Payment:
- Shipping:
Inventory:199
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Product details
Overview
FCX491QTA from Diodes Incorporated is a 60V NPN medium-power transistor in SOT89 package, rated for 1A continuous collector current and 2A peak pulse current, with VCE(sat) ≤ 250 mV at IC = 1A/IB = 100mA, hFE ≥ 30 at 2A, and qualified to AEC-Q101 for automotive power switching applications including DC-DC converter primary-side switches and motor driver stages.
For engineers reviewing the FCX491QTA datasheet, FCX491QTA pinout, FCX491QTA application, or FCX491QTA equivalent, key selection criteria include its 60V VCEO, low RCE(sat) of 195 mΩ (typical), thermal resistance RθJC = 16°C/W, AEC-Q101 qualification, and complementary PNP pairing with FCX591QTA in SOT89.
Technical Context
This NPN bipolar junction transistor operates as a medium-power linear or switching device with base-driven control, supporting continuous conduction up to 1A and pulsed loads to 2A. Its VCEO = 60V and VCBO = 80V enable use in 48V automotive subsystems and industrial 24–48V rails.
The device features characterized hFE across 1mA–2A (min 30 at 2A), fT = 150 MHz, and fast switching performance (ton = 49 ns, toff = 476 ns), making it suitable for PWM-controlled power stages where gain stability and turn-off speed are critical.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 60 V - Maximum sustainable collector-emitter voltage under operating conditions; defines safe operation in 48V automotive systems. |
| IC (continuous) | 1 A - Continuous DC collector current rating; determines steady-state power handling without derating at 25°C ambient. |
| VCE(sat) | 250 mV max @ IC=1A/IB=100mA - Low saturation voltage minimizes conduction loss in switching applications. |
| hFE | 30 min @ IC=2A/VCE=5V - Confirmed current gain at high current ensures reliable base drive sizing for 2A pulses. |
| RθJC | 16 °C/W - Junction-to-case thermal resistance enables direct heat transfer to PCB copper or heatsink via exposed collector pad. |
| fT | 150 MHz - Transition frequency supports stable operation in high-frequency PWM circuits up to ~10–20 MHz practical switching. |
| ESD HBM | 4,000 V - Human Body Model ESD rating confirms robustness during board assembly and handling in automotive production. |
Pinout & Package
SOT89 package with exposed collector pad for thermal dissipation; molded green compound, matte tin-plated leads, moisture sensitivity level 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Collector (C) | Main current output path | Connected to exposed metal tab; must be soldered to ≥15 mm² 1 oz copper for full 1 W power rating. |
| Emitter (E) | Current return path | Low-impedance reference node; ties to ground or low-side switch common point. |
| Base (B) | Control input | Receives current-limited drive signal; requires ≥100 mA for full 1A saturation per hFE data. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive temperature range (−65°C to +150°C) and reliability stress testing per JEDEC standard. |
| Exposed collector pad | Enables direct thermal coupling to PCB copper; achieves RθJC = 16°C/W and supports 2.0 W power dissipation on 50 mm² 1 oz copper. |
| Complementary PNP pairing | FCX591QTA shares identical SOT89 footprint and thermal profile, enabling matched push-pull or H-bridge designs. |
| Green construction | Halogen- and antimony-free molding compound (<900 ppm Br/Cl, <1000 ppm Sb); fully RoHS 2 compliant with no added lead. |
Applications
| Automotive Door Module | Industrial 48V DC-DC Converter |
|---|---|
Use Scenario: Driving window lift motors and mirror actuators in body control modules. IC Role / Device Role / Timing Role: NPN power switch controlling 1A inductive loads with PWM duty cycling. Use Value: 60V VCEO withstands load-dump transients; 2A ICM handles motor stall currents without secondary protection. |
Use Scenario: Primary-side switching element in non-isolated buck converters for industrial PLC I/O power supplies. IC Role / Device Role / Timing Role: Medium-power BJT switch operating at 100–500 kHz with base-driven gate control. Use Value: 150 MHz fT and 49 ns ton support efficient high-frequency operation; RθJC = 16°C/W simplifies thermal design on 2-layer boards. |
| LED Headlamp Driver | Smart HVAC Actuator |
Use Scenario: Constant-current switching stage regulating high-brightness LED strings in adaptive front lighting systems. IC Role / Device Role / Timing Role: Linear or PWM-controlled current source with analog feedback loop compensation. Use Value: hFE ≥ 30 at 2A ensures stable current regulation under dimming transients; AEC-Q101 ensures field longevity. |
Use Scenario: Position-control driver for stepper or brushed DC actuators in climate control dampers. IC Role / Device Role / Timing Role: Half-bridge low-side switch enabling bidirectional motor control with external high-side. Use Value: Complementary FCX591QTA pairing allows compact SOT89-based H-bridge layout; 476 ns toff limits shoot-through risk. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN medium-power transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ZXTN25050DFHTA | VCEO = 50V (lower), IC = 1.5A, SOT23 package, RθJA = 275°C/W (higher) | Not AEC-Q101 qualified; unsuitable for automotive; limited to low-power consumer applications | Select only for cost-sensitive, non-automotive designs where 50V rating suffices and thermal budget permits higher RθJA. |
| MJD127G | VCEO = 100V, IC = 2A, TO-252 package, RθJC = 3°C/W (lower), no AEC-Q101 | Larger footprint, higher thermal performance, but lacks automotive qualification and green compliance | Prefer for industrial 100V systems requiring higher surge margin and lower thermal resistance, accepting larger size and no automotive traceability. |
Compared with ZXTN25050DFHTA and MJD127G, FCX491QTA uniquely balances AEC-Q101 compliance, 60V/1A capability, SOT89 thermal efficiency (RθJC = 16°C/W), and halogen-free construction-making it the only choice for space-constrained, thermally demanding automotive power stages requiring full PPAP documentation.
Availability
FCX491QTA is available at Aetrix Electronics and suitable for automotive door modules, industrial 48V DC-DC converters, and smart HVAC actuators requiring stable component supply with full AEC-Q101 traceability and green compliance.
Supply support for FCX491QTA 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, specializing in high-reliability components for automotive, industrial, and computing markets with ISO/TS 16949-certified operations.
The FCX491QTA belongs to Diodes' AEC-Q101-qualified medium-power transistor product line, designed specifically for thermally constrained automotive body electronics and industrial power interfaces requiring robust transient immunity and long-term reliability.
FAQ
What is the maximum allowable PCB copper area needed to achieve the 2.0 W power rating?
The 2.0 W rating is specified when mounted on 50 mm × 50 mm (2500 mm²) of 1 oz copper on a single-sided FR4 PCB. This configuration yields RθJA = 60°C/W. Smaller copper areas increase thermal resistance proportionally-e.g., 15 mm × 15 mm (225 mm²) gives RθJA = 125°C/W and limits power to 1.0 W at TA = 25°C.
Is FCX491QTA pin-compatible with FCX491TA, and what distinguishes them?
Yes-both share identical SOT89 pinout, electrical specs, and thermal characteristics. The "Q" suffix denotes automotive qualification (AEC-Q101 and PPAP capable), while "TA" is the standard-grade version. Marking code "N1" and reel packaging (1,000 pcs/12 mm tape) are identical; only compliance documentation differs.
Can FCX491QTA replace a MOSFET in low-frequency switching applications?
Yes, for ≤100 kHz switching where gate drive simplicity and cost matter more than ultra-low RDS(on). Its 250 mV VCE(sat) at 1A yields ~0.25 W conduction loss-comparable to many small-signal MOSFETs-but requires sustained base current (≥100 mA), unlike voltage-driven MOSFET gates.
Does the exposed collector pad require solder mask opening or thermal via placement?
Yes-the exposed collector pad must be soldered directly to a solid copper pour with no solder mask over the pad area. Thermal vias (≥4× 0.3 mm diameter) are recommended beneath the pad to transfer heat to inner or back-layer copper, especially when operating above 0.5 W continuously.
FCX491QTA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- TO-243AA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Transistor Type:
- NPN
- Current - Collector (Ic) (Max):
- 1 A
- Voltage - Collector Emitter Breakdown (Max):
- 60 V
- Vce Saturation (Max) @ Ib, Ic:
- 500mV @ 100mA, 1A
- Current - Collector Cutoff (Max):
- 100nA
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 100 @ 500mA, 5V
- Power - Max:
- 1 W
- Frequency - Transition:
- 150MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-89-3
FCX491QTA FAQ
1.How can I place an order for FCX491QTA through Aetrix?
Please submit a Request for Quotation (RFQ) for FCX491QTA 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 FCX491QTA reliable?
The price and inventory of FCX491QTA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FCX491QTA is usually 5 days.
3.What payment methods are accepted for FCX491QTA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FCX491QTA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for FCX491QTA?
FCX491QTA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your FCX491QTA 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 FCX491QTA?
For technical support, including FCX491QTA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FCX491QTA requirements.
6.How does Aetrix verify that FCX491QTA is sourced from the original manufacturer or authorized distributors?
All FCX491QTA 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 FCX491QTA meets industry standards.
7.What is the process for return or replacement of FCX491QTA?
All FCX491QTA units undergo pre-shipment inspection (PSI). If there is an issue with FCX491QTA, 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 FCX491QTA part is unused and in its original packaging.
Return procedure for FCX491QTA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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