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Diodes Incorporated FZT491ATA
- Part No.:
- FZT491ATA
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Bipolar Transistors
- Package:
- TO-261-4, TO-261AA
- Datasheet:
-
FZT491ATA.pdf
- Description:
- TRANS NPN 40V 1A SOT-223-3
- Quantity:
- Payment:
- Shipping:
Inventory:6,821
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Product details
Overview
FZT491ATA from Diodes Incorporated is a 40V, 1A NPN medium-power transistor in SOT223 package, featuring VCE(SAT) < 500 mV at 1 A, BVCEO ≥ 40 V, and AEC-Q101 qualification. It serves as a high-current switching element in gate drive and power control circuits, delivering low-loss operation in automotive and industrial DC-DC converters.
For engineers reviewing the FZT491ATA datasheet, FZT491ATA pinout, FZT491ATA application, or FZT491ATA equivalent, key selection criteria include saturation voltage at 1 A, thermal resistance (RθJA = 41.7 °C/W on 50 mm × 50 mm 2 oz Cu), peak pulse current rating (2 A), and AEC-Q101 reliability compliance for automotive-grade designs.
Technical Context
This NPN bipolar junction transistor operates in linear or saturated switching mode with DC current gain (hFE) ranging from 35 to 900 across 1 mA–2 A collector current. Its fT of 150 MHz supports fast switching in gate driver stages while maintaining robust SOA under pulsed loads.
The device uses a thermally enhanced SOT223 (Type DN) package with exposed collector lead for low RθJL (19.4 °C/W), enabling reliable 3.0 W power dissipation when mounted on 50 mm × 50 mm 2 oz copper PCB - critical for sustained 1 A continuous conduction in compact power stages.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 40 V - Ensures safe operation in 24 V and 36 V automotive and industrial bus systems with margin. |
| IC (continuous) | 1 A - Supports direct MOSFET gate charging for logic-level and standard-threshold power FETs. |
| VCE(SAT) | 0.5 V max @ 1 A/100 mA - Limits conduction loss to ≤500 mW, reducing thermal load in high-duty-cycle drivers. |
| hFE | 35–900 @ IC = 1 mA–2 A - Enables stable biasing across wide current range without external gain compensation. |
| fT | 150 MHz - Allows clean turn-on/turn-off edges for PWM frequencies up to ~10 MHz in gate drive applications. |
| RθJA | 41.7 °C/W - Requires only moderate copper area for thermal management in space-constrained PCB layouts. |
| ESD HBM | 8 kV - Provides robust handling during assembly and board-level integration without additional protection circuitry. |
Pinout & Package
SOT223 (Type DN) package with molded green plastic housing, UL 94V-0 rated, and matte tin-plated leads solderable per MIL-STD-202 Method 208. Exposed collector tab enables low thermal resistance path to PCB copper.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Emitter (E) | Current sink terminal | Connected to ground or low-side return path; defines reference for base drive and current sensing. |
| Base (B) | Control input | Receives TTL/CMOS-compatible drive current (≤100 mA) to saturate transistor at 1 A collector load. |
| Collector (C) | Power output terminal | Exposed metal tab - must be connected to large copper pour for thermal and current conduction; primary power path to load. |
| Tab / Heat Sink Pad | Thermal & electrical extension of collector | Electrically tied to collector; provides mechanical mounting surface and thermal interface to PCB heatsink area. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive power electronics including engine control modules and body electronics. |
| VCE(SAT) < 500 mV @ 1 A | Reduces conduction loss by >30% vs. legacy 1 A transistors, lowering temperature rise in gate driver IC replacements. |
| ICM = 2 A peak pulse | Handles inrush currents during MOSFET turn-on without secondary overcurrent protection. |
| Lead-free, halogen-free, RoHS 3 compliant | Meets global environmental regulations and enables use in consumer, industrial, and automotive supply chains. |
| Complementary PNP: FZT591A | Enables matched push-pull or H-bridge configurations with consistent thermal and switching behavior. |
Applications
| Automotive Gate Driver | Industrial DC-DC Converter |
|---|---|
Use Scenario: Driving high-side N-channel MOSFETs in 12 V/24 V automotive power distribution units. IC Role / Device Role / Timing Role: NPN switch providing low-impedance path from gate to ground during turn-off, ensuring fast and complete MOSFET discharge. Use Value: VCE(SAT) ≤ 0.5 V at 1 A minimizes energy loss during gate discharge, improving system efficiency and thermal stability. | Use Scenario: Controlling synchronous rectifier or auxiliary power switch in isolated flyback or forward converters. IC Role / Device Role / Timing Role: Medium-power switching transistor used in discrete gate driver or level-shifting stage for main power switches. Use Value: 150 MHz fT ensures sharp edge fidelity for PWM signals up to 5 MHz, preserving timing accuracy in high-frequency topologies. |
| LED Driver Current Sink | Motor Control Interface |
Use Scenario: Constant-current sinking for high-brightness LED strings in commercial signage and lighting systems. IC Role / Device Role / Timing Role: Linear or PWM-controlled current regulator operating in active region with feedback from sense resistor. Use Value: hFE stability across 100 mA–1 A enables precise analog current regulation without gain drift or thermal runaway. | Use Scenario: Isolated logic-level translation and current amplification for stepper motor phase drivers in CNC equipment. IC Role / Device Role / Timing Role: Discrete buffer between microcontroller GPIO and MOSFET gate, providing 100 mA base drive capability. Use Value: 2 A ICM rating accommodates transient gate charge demands during rapid direction reversal, preventing missed steps. |
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 |
|---|---|---|---|
| ZXTN2012ZTA | Higher VCEO (60 V), lower hFE (min 100), SOT89 package | Better voltage margin but less current gain; requires larger base drive for same IC | Preferred where 60 V bus isolation is required and PCB space allows SOT89 footprint. |
| MJD44H11T4G | TO-252 package, higher PD (15 W), slower fT (3 MHz) | Superior thermal performance for >1 A continuous, but unsuitable for high-speed gate driving | Select when thermal headroom is critical and switching frequency is below 100 kHz. |
Compared with ZXTN2012ZTA and MJD44H11T4G, FZT491ATA uniquely balances 1 A current, 150 MHz fT, and AEC-Q101 qualification in a compact SOT223 - making it optimal for space-constrained, high-reliability gate drive applications where speed and automotive compliance intersect.
Availability
FZT491ATA is available at Aetrix Electronics and suitable for automotive gate drivers, industrial DC-DC converters, LED current sinks, and motor control interfaces requiring stable component supply and AEC-Q101 traceability.
Supply support for FZT491ATA 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 FZT491ATA belongs to Diodes' AEC-Q101-qualified medium-power transistor family, engineered specifically for robust gate driving and power switching in harsh-environment applications where thermal stability and long-term reliability are mandatory.
FAQ
What is the maximum continuous collector current for FZT491ATA?
The FZT491ATA supports 1 A continuous collector current at TA = +25°C with proper PCB thermal design (50 mm × 50 mm 2 oz Cu). Derating applies above +25°C ambient - e.g., ~0.8 A at +85°C ambient per the published derating curve.
Is FZT491ATA pin-compatible with other SOT223 NPN transistors?
FZT491ATA follows standard SOT223 (Type DN) pinout: Collector (tab), Base, Emitter - matching industry-standard layout. However, electrical parameters (e.g., hFE, VCE(SAT)) differ significantly from generic SOT223 transistors, so functional substitution requires validation against target circuit requirements.
Does FZT491ATA require a heatsink in typical applications?
No dedicated heatsink is required. With its RθJA = 41.7 °C/W on 50 mm × 50 mm 2 oz Cu, the device stays within safe junction temperature limits (<150°C) at 1 A and +85°C ambient. The exposed collector tab must be soldered to ≥2 cm² of copper for effective heat spreading.
What is the complementary PNP part for FZT491ATA?
The officially specified complementary PNP transistor is FZT591A - identical SOT223 package, matched BVCEO (40 V), IC (1 A), and AEC-Q101 qualification. It enables balanced push-pull, H-bridge, or differential amplifier designs with matched thermal and electrical characteristics.
FZT491ATA 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:
- 2 W
- Frequency - Transition:
- 150MHz
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-223-3
FZT491ATA FAQ
1.How can I place an order for FZT491ATA through Aetrix?
Please submit a Request for Quotation (RFQ) for FZT491ATA 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 FZT491ATA reliable?
The price and inventory of FZT491ATA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FZT491ATA is usually 5 days.
3.What payment methods are accepted for FZT491ATA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FZT491ATA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for FZT491ATA?
FZT491ATA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your FZT491ATA 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 FZT491ATA?
For technical support, including FZT491ATA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FZT491ATA requirements.
6.How does Aetrix verify that FZT491ATA is sourced from the original manufacturer or authorized distributors?
All FZT491ATA 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 FZT491ATA meets industry standards.
7.What is the process for return or replacement of FZT491ATA?
All FZT491ATA units undergo pre-shipment inspection (PSI). If there is an issue with FZT491ATA, 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 FZT491ATA part is unused and in its original packaging.
Return procedure for FZT491ATA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
FZT491ATA Tags
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