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Diodes Incorporated FZT491AQTA
- Part No.:
- FZT491AQTA
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Bipolar Transistors
- Package:
- TO-261-4, TO-261AA
- Datasheet:
-
FZT491AQTA.pdf
- Description:
- TRANS NPN 40V 1A SOT-223
- Quantity:
- Payment:
- Shipping:
Inventory:720
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Product details
Overview
FZT491AQTA from Diodes Incorporated is a 40V, 1A NPN medium-power transistor in SOT223 package, designed for high-reliability automotive gate driving and low-loss switching applications. It delivers VCE(SAT) < 500 mV at 1 A, supports 2 A peak pulse current, and is qualified to AEC-Q101 standards.
For engineers reviewing the FZT491AQTA datasheet, FZT491AQTA pinout, FZT491AQTA application, or FZT491AQTA equivalent, key selection criteria include its 40 V VCEO, 3.0 W power dissipation on 50 mm × 50 mm 2 oz copper, low saturation voltage under 1 A load, and automotive-grade qualification with PPAP capability.
Technical Context
This NPN bipolar junction transistor operates as a medium-power switch with fixed gain structure optimized for linear and saturated-mode operation. Its BVCEO = 40 V and IC = 1 A continuous rating enable robust gate drive of power MOSFETs in DC-DC converters and motor control stages.
The device features low thermal resistance (RθJA = 41.7 °C/W on 50 mm × 50 mm 2 oz copper) and high ESD tolerance (8 kV HBM), supporting stable performance in thermally constrained automotive PCB layouts with minimal heatsinking.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 40 V - Maximum collector-emitter voltage before breakdown; defines safe operating range in 24 V and 36 V automotive systems. |
| IC (continuous) | 1 A - Sustained collector current capacity; supports direct drive of medium-current MOSFET gates without external buffering. |
| VCE(SAT) | < 500 mV @ 1 A/100 mA - Low saturation voltage minimizes conduction loss and self-heating during switching transitions. |
| hFE | 300–900 @ IC = 1 mA to 1 A - Wide DC current gain range ensures reliable turn-on across production lots and temperature extremes. |
| fT | 150 MHz - Transition frequency enables stable operation up to ~10 MHz switching frequencies with adequate gain margin. |
| RθJA | 41.7 °C/W - Thermal resistance on standard 50 mm × 50 mm 2 oz copper; allows ~70 °C rise at full 3.0 W dissipation. |
Pinout & Package
Package: SOT223 (Type DN), surface-mount, 3-terminal plastic case with exposed collector tab for thermal conduction. Weight: 0.112 g. Moisture sensitivity level: J-STD-020 Level 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Collector (C) | Main current output path | Exposed metal tab - must be soldered to large copper pour for thermal management and electrical connection. |
| Emitter (E) | Current return path to ground/reference | Low-impedance terminal; connects directly to system ground plane in gate-drive configurations. |
| Base (B) | Control input for transistor biasing | High-impedance input requiring ~100 mA drive for full saturation at 1 A collector current. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive use including temperature cycling, humidity, and mechanical shock per AEC specification. |
| Lead-free & Green | Meets RoHS 3 (2015/863/EU); halogen- and antimony-free molding compound with UL 94V-0 flammability rating. |
| High ESD immunity | 8 kV HBM rating enables handling and assembly without special ESD controls beyond standard Class 3B requirements. |
| Complementary PNP pair | FZT591A available for push-pull or H-bridge topologies requiring matched thermal and electrical characteristics. |
Applications
| Power MOSFET Gate Driving | Automotive Load Switching |
|---|---|
Use Scenario: Driving the gate of N-channel power MOSFETs in 12 V/24 V automotive DC-DC converters and body control modules. IC Role / Device Role / Timing Role: NPN switch providing fast, low-loss turn-on of high-capacitance MOSFET gates with controlled dV/dt. Use Value: VCE(SAT) < 500 mV at 1 A reduces gate-drive power loss by >30% vs. standard small-signal transistors. | Use Scenario: Controlling 12 V solenoid valves, fuel pumps, and HVAC actuators in engine management systems. IC Role / Device Role / Timing Role: Medium-power discrete switch replacing relays or higher-cost integrated load switches. Use Value: 40 V VCEO and 2 A ICM support transient overvoltage protection during load dump events per ISO 7637-2. |
| Industrial Motor Control | LED Driver Current Switching |
Use Scenario: Base drive for IGBTs or MOSFETs in BLDC motor inverters for power tools and HVAC fans. IC Role / Device Role / Timing Role: High-current interface between microcontroller GPIO and power stage gate drivers. Use Value: 150 MHz fT ensures clean switching edge integrity up to 10 MHz PWM frequencies without phase lag. | Use Scenario: Constant-current switching in high-brightness LED arrays for automotive lighting and signage. IC Role / Device Role / Timing Role: Linear or saturated-mode current regulator with precision base bias control. Use Value: Tight hFE distribution (300–900) enables consistent LED current matching across production units without trimming. |
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 |
|---|---|---|---|
| ZXTN25012E6TA | Higher VCEO (60 V), lower IC (0.5 A), SOT23 package | Better suited for low-current, high-voltage sensing; not rated for 1 A continuous loads | Select when board space is critical and current demand ≤ 500 mA. |
| MJD44H11RLG | TO-220 package, higher IC (8 A), slower fT (3 MHz) | Requires heatsink; suitable for high-power linear regulation but not high-frequency switching | Select when thermal mass and ruggedness outweigh switching speed and footprint constraints. |
Compared with ZXTN25012E6TA and MJD44H11RLG, FZT491AQTA uniquely balances 1 A continuous current, 40 V rating, SOT223 footprint, and 150 MHz fT-making it optimal for space-constrained, high-reliability automotive gate drive where thermal performance and switching fidelity are jointly critical.
Availability
FZT491AQTA is available at Aetrix Electronics and suitable for automotive gate driving, industrial motor control, LED current switching, and 24 V load switching requiring stable component supply and AEC-Q101 compliance.
Supply support for FZT491AQTA 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.
The FZT491AQTA belongs to Diodes' AEC-Q101-qualified medium-power transistor product line, engineered specifically for robust gate driving and switching in harsh automotive environments with extended temperature and vibration requirements.
FAQ
What is the maximum allowable junction temperature for FZT491AQTA?
The absolute maximum junction temperature is +150 °C, with storage temperature ranging from –55 °C to +150 °C. Derating begins above +25 °C ambient, and full 3.0 W power dissipation requires a thermal pad layout meeting Diodes' 50 mm × 50 mm 2 oz copper specification.
Is FZT491AQTA pin-compatible with FZT491A?
Yes-FZT491AQTA and FZT491A share identical SOT223 pinout, electrical specifications, and thermal characteristics. The "QTA" suffix denotes automotive qualification (AEC-Q101, PPAP capable), while "TA" indicates standard industrial grade; both use the same die and package.
Can FZT491AQTA replace a MOSFET in low-side switching applications?
No-it is a bipolar NPN transistor requiring sustained base current for conduction, unlike voltage-driven MOSFETs. It excels in gate driving and moderate-speed switching but lacks the zero-gate-drive advantage and ultra-low RDS(on) of power MOSFETs in high-efficiency DC-DC stages.
What is the recommended PCB pad layout for thermal performance?
Diodes specifies a minimum pad layout with 50 mm × 50 mm 2 oz copper for 3.0 W operation. The exposed collector tab must be fully soldered to this copper area. Recommended dimensions are provided in Package Outline DS33136 Rev. 5–2, Figure 6, with thermal vias strongly advised beneath the tab for multilayer boards.
FZT491AQTA 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):
- 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:
- 3 W
- Frequency - Transition:
- 150MHz
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-223
FZT491AQTA FAQ
1.How can I place an order for FZT491AQTA through Aetrix?
Please submit a Request for Quotation (RFQ) for FZT491AQTA 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 FZT491AQTA reliable?
The price and inventory of FZT491AQTA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FZT491AQTA is usually 5 days.
3.What payment methods are accepted for FZT491AQTA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FZT491AQTA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for FZT491AQTA?
FZT491AQTA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your FZT491AQTA 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 FZT491AQTA?
For technical support, including FZT491AQTA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FZT491AQTA requirements.
6.How does Aetrix verify that FZT491AQTA is sourced from the original manufacturer or authorized distributors?
All FZT491AQTA 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 FZT491AQTA meets industry standards.
7.What is the process for return or replacement of FZT491AQTA?
All FZT491AQTA units undergo pre-shipment inspection (PSI). If there is an issue with FZT491AQTA, 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 FZT491AQTA part is unused and in its original packaging.
Return procedure for FZT491AQTA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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