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Diodes Incorporated FCX491ATA
- Part No.:
- FCX491ATA
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Bipolar Transistors
- Package:
- TO-243AA
- Datasheet:
-
FCX491ATA.pdf
- Description:
- TRANS NPN 40V 1A SOT-89-3
- Quantity:
- Payment:
- Shipping:
Inventory:32,013
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Product details
Overview
FCX491ATA from Diodes Incorporated is a 40V NPN medium-power transistor in SOT89 package, rated for 1A continuous collector current, with VCE(sat) < 500 mV at 1A and BVCEO > 40 V. It serves as a high-current switching element in power MOSFET gate drive circuits and low-loss DC switching applications.
For engineers reviewing the FCX491ATA datasheet, FCX491ATA pinout, FCX491ATA application, or FCX491ATA equivalent, key selection criteria include its 1A IC rating, 40V VCEO, SOT89 thermal performance (RθJL = 10.01 °C/W), complementary PNP pairing with FCX591A, and automotive-grade variant availability (FCX491AQ).
Technical Context
This NPN bipolar junction transistor operates in linear or saturated switching mode with guaranteed hFE of 300–900 across IC = 1 mA to 1 A, enabling robust current amplification in driver stages. Its fT = 150 MHz supports fast switching transitions in gate-drive applications.
The device features low VCE(sat) (≤500 mV @ 1A/100mA) and high breakdown ratings (VCBO = VCEO = 40 V, VEBO = 7 V), making it suitable for 24V industrial control rails and 12V/24V automotive auxiliary switching where low conduction loss and reliability under transient stress are critical.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 40 V - Maximum safe collector-emitter voltage before avalanche breakdown; enables use in 24V systems with margin. |
| IC (continuous) | 1 A - Sustained collector current capability; supports driving logic-level MOSFET gates or small solenoids. |
| VCE(sat) | <500 mV @ 1A/100mA - Low saturation voltage minimizes power loss (≤0.5 W) during on-state operation. |
| hFE | 300–900 @ IC = 1 mA–1 A - Wide DC current gain range ensures stable biasing across load variations. |
| fT | 150 MHz - Transition frequency supports sub-100 ns switching edges in gate-drive applications. |
| RθJL | 10.01 °C/W - Junction-to-leads thermal resistance enables efficient heat transfer to PCB copper via exposed collector pad. |
Pinout & Package
Package: SOT89 - Surface-mount plastic package with exposed collector pad for enhanced thermal dissipation; UL 94V-0 rated, moisture sensitivity level 1, weight ≈ 0.05 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Collector (C) | Main current output terminal | Connected to exposed metal tab; primary thermal path to PCB; must be soldered to ≥15 mm × 15 mm copper area. |
| Emitter (E) | Current return path | Low-impedance ground reference; forms emitter-follower or common-emitter switch node. |
| Base (B) | Control input | Receives current-limited drive signal (e.g., 100 mA typical for 1A IC); requires series resistor for TTL/CMOS interface. |
Key Features
| Feature | Design Value |
|---|---|
| High current capability | 1 A continuous collector current supports direct drive of power MOSFET gates without external buffer stages. |
| Low saturation loss | VCE(sat) ≤ 500 mV at full 1A load reduces conduction loss to <0.5 W, easing thermal design in compact layouts. |
| Complementary PNP pairing | FCX591A provides matched characteristics for push-pull or H-bridge output stages requiring dual polarity switching. |
| Automotive-qualified variant | FCX491AQ meets AEC-Q101 requirements, enabling drop-in use in automotive body electronics and ADAS subsystems. |
Applications
| Power MOSFET Gate Driving | Low-Loss DC Power Switching |
|---|---|
Use Scenario: Driving the gate of a logic-level N-channel MOSFET in a 24V DC-DC converter half-bridge stage. IC Role / Device Role / Timing Role: NPN switch providing high peak current (≥1A) to rapidly charge/discharge MOSFET gate capacitance. Use Value: VCE(sat) < 500 mV ensures minimal voltage drop during gate pull-down, preserving gate drive voltage margin and reducing switching transition time. | Use Scenario: Controlling 12V/24V solenoid valves or LED arrays in industrial PLC output modules. IC Role / Device Role / Timing Role: Medium-power discrete switch replacing mechanical relays for solid-state, long-life load control. Use Value: 40V VCEO and 1A IC support direct connection to 24V bus with flyback diode protection, eliminating need for additional current-limiting circuitry. |
| Automotive Body Control | Industrial Motor Start/Stop |
Use Scenario: Driving window lift motors or mirror adjustment actuators in AEC-Q101-compliant vehicle platforms (using FCX491AQ). IC Role / Device Role / Timing Role: High-reliability NPN switch interfacing microcontroller GPIO to motor winding. Use Value: RθJL = 10.01 °C/W and -65°C to +150°C operating range ensure stable operation under under-hood thermal cycling and load transients. | Use Scenario: Enabling/disabling small DC brush motors (e.g., fans, pumps) in HVAC control panels. IC Role / Device Role / Timing Role: Low-loss switching element in motor enable path, controlled by PWM or digital logic. Use Value: hFE ≥ 300 at 1A allows simple base-resistor biasing from 3.3V/5V MCU outputs, reducing BOM count versus Darlington alternatives. |
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 |
|---|---|---|---|
| ZTX653 | Higher VCEO (60 V), lower IC (0.5 A), TO-92 package | Limited to lower-current loads; unsuitable for 1A gate drive or solenoid switching | Select when higher voltage margin is needed but current demand is ≤500 mA and through-hole mounting is preferred. |
| MJD44H11T4G | Higher IC (8 A), TO-252 package, slower fT (3 MHz) | Better for high-current linear regulation; too large and slow for fast gate drive | Choose for high-power linear pass elements or relay drivers where thermal mass outweighs switching speed needs. |
Compared with ZTX653 and MJD44H11T4G, FCX491ATA uniquely balances 1A current, 40V rating, SOT89 thermal efficiency, and 150 MHz fT-making it optimal for space-constrained, fast-switching gate-drive and 24V industrial switching where both current and speed matter.
Availability
FCX491ATA is available at Aetrix Electronics and suitable for power MOSFET gate driving, low-loss DC power switching, and automotive body control applications requiring stable component supply and RoHS-compliant packaging.
Supply support for FCX491ATA 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, energy-efficient components for industrial, automotive, and consumer markets.
The FCX491ATA belongs to Diodes' medium-power bipolar transistor product line, engineered specifically for high-current, low-saturation switching in space-constrained surface-mount applications such as gate drivers and DC load control.
FAQ
What is the maximum allowable junction temperature for FCX491ATA?
The FCX491ATA has an operating junction temperature range of –65°C to +150°C. Under continuous 1A operation with proper PCB copper heatsinking (15 mm × 15 mm, 1 oz Cu), junction temperature remains within limits due to its RθJL of 10.01 °C/W and 1 W power dissipation rating.
Can FCX491ATA be used in linear amplifier configurations?
Yes, FCX491ATA supports linear operation with hFE = 300–900 across IC = 1 mA–1 A and fT = 150 MHz, but its 1 W power limit and thermal design require careful derating above 25°C ambient. It is optimized for switching, not high-fidelity analog amplification.
Is FCX491ATA pin-compatible with FCX591A?
No-FCX491ATA (NPN) and FCX591A (PNP) share the same SOT89 package and pinout order (C-E-B), but their complementary polarity means they cannot be interchanged without circuit redesign. Both use identical mechanical layout and thermal pad configuration.
Does FCX491ATA meet automotive qualification standards?
The standard FCX491ATA is not AEC-Q101 qualified; however, the automotive-grade variant FCX491AQ is fully qualified per AEC-Q101 and shares identical electrical specifications and SOT89 footprint, enabling seamless migration for automotive designs.
FCX491ATA 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):
- 40 V
- Vce Saturation (Max) @ Ib, Ic:
- 500mV @ 100mA, 1A
- Current - Collector Cutoff (Max):
- 100nA
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 300 @ 500mA, 5V
- Power - Max:
- 1 W
- Frequency - Transition:
- 150MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-89-3
FCX491ATA FAQ
1.How can I place an order for FCX491ATA through Aetrix?
Please submit a Request for Quotation (RFQ) for FCX491ATA 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 FCX491ATA reliable?
The price and inventory of FCX491ATA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FCX491ATA is usually 5 days.
3.What payment methods are accepted for FCX491ATA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FCX491ATA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for FCX491ATA?
FCX491ATA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your FCX491ATA 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 FCX491ATA?
For technical support, including FCX491ATA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FCX491ATA requirements.
6.How does Aetrix verify that FCX491ATA is sourced from the original manufacturer or authorized distributors?
All FCX491ATA 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 FCX491ATA meets industry standards.
7.What is the process for return or replacement of FCX491ATA?
All FCX491ATA units undergo pre-shipment inspection (PSI). If there is an issue with FCX491ATA, 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 FCX491ATA part is unused and in its original packaging.
Return procedure for FCX491ATA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
FCX491ATA Tags
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