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Diodes Incorporated FZT491TA
- Part No.:
- FZT491TA
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Bipolar Transistors
- Package:
- TO-261-4, TO-261AA
- Datasheet:
-
FZT491TA.pdf
- Description:
- TRANS NPN 60V 1A SOT-223-3
- Quantity:
- Payment:
- Shipping:
Inventory:6,801
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Product details
Overview
FZT491TA from Diodes Incorporated is a 60V NPN medium-power transistor in SOT223 package, rated for 1A continuous collector current, with VCE(sat) ≤ 500 mV at 1A/100 mA drive, and qualified to AEC-Q101 for automotive reliability. It serves as a robust low-loss switch in power management stages, particularly for MOSFET gate driving and DC-DC converter control circuits.
For engineers reviewing the FZT491TA datasheet, FZT491TA pinout, FZT491TA application, or FZT491TA equivalent, key selection criteria include its 60V VCEO, 1A IC, thermal resistance of 41.7°C/W on 50mm×50mm 2oz copper, AEC-Q101 qualification, and complementary PNP pairing with FZT591TA.
Technical Context
This NPN bipolar junction transistor operates in linear or saturated switching mode with guaranteed BVCEO ≥ 60 V and VBE(sat) ≤ 1.1 V at 1A/100 mA. Its fT = 150 MHz supports high-speed switching up to several hundred kHz in power control loops.
Thermal performance is defined for two PCB mounting conditions: RθJA = 62.5°C/W (25mm×25mm 1oz) and 41.7°C/W (50mm×50mm 2oz), enabling accurate junction temperature estimation under steady-state or pulsed load conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 60 V - Maximum safe collector-emitter voltage before breakdown in common-emitter configuration. |
| IC (continuous) | 1 A - Continuous collector current rating defining maximum DC load-handling capability. |
| VCE(sat) | ≤500 mV @ 1A/100 mA - Low saturation voltage ensures minimal conduction loss in switching applications. |
| hFE | 100–300 @ IC = 1mA–2A - DC current gain range supporting stable biasing across operating currents. |
| fT | 150 MHz - Transition frequency enabling reliable operation in high-frequency switching and driver stages. |
| RθJA | 41.7 °C/W - Thermal resistance on 50mm×50mm 2oz FR4, critical for thermal design margin in power circuits. |
| AEC-Q101 | Qualified - Confirmed reliability for automotive-grade applications including under-hood power control. |
Pinout & Package
Package: SOT223 - Surface-mount plastic package with exposed collector tab for enhanced thermal dissipation; 0.112 g mass; UL 94V-0 flammability rating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Emitter (E) | Current sink terminal | Low-impedance return path; connected to ground or low-side reference in switch configurations. |
| Base (B) | Control input | Receives drive current (max 200 mA) to saturate or cut off the transistor; requires current-limiting resistor. |
| Collector (C) | Current source terminal | High-current output node; electrically and thermally tied to exposed metal tab for PCB heat sinking. |
| Tab / Collector Pad | Thermal & electrical connection | Integral part of collector; must be soldered to large copper pour for thermal management per RθJL = 19.41°C/W. |
Key Features
| Feature | Design Value |
|---|---|
| 60V VCEO rating | Enables use in 48V automotive and industrial power rails without derating. |
| 1A continuous IC | Supports direct drive of small-to-medium power MOSFET gates or relay coils without external buffering. |
| VCE(sat) ≤ 500 mV | Reduces conduction loss to <500 mW at full load, improving efficiency in high-duty-cycle switches. |
| AEC-Q101 qualification | Validates suitability for automotive body electronics, lighting, and engine control modules. |
| Complementary PNP (FZT591TA) | Enables matched push-pull or H-bridge output stages with consistent thermal and gain behavior. |
Applications
| Automotive LED Driver | DC-DC Converter Switch |
|---|---|
Use Scenario: Driving high-brightness LED strings in vehicle interior lighting with PWM dimming. IC Role / Device Role / Timing Role: NPN switch controlling LED current path; operated in saturation for low-loss on-state. Use Value: VCE(sat) ≤ 500 mV minimizes heat generation at 1A drive, enabling compact heatsink-free designs. | Use Scenario: Low-side synchronous rectifier or main switch in buck converter for 12V–48V input systems. IC Role / Device Role / Timing Role: Power switching element handling up to 1A continuous current with fast turn-on/off via base drive. Use Value: fT = 150 MHz and low storage time support efficient operation up to 500 kHz switching frequencies. |
| MOSFET Gate Driver | Industrial Relay Interface |
Use Scenario: Level-shifting and current-boosting stage to drive N-channel power MOSFET gates from microcontroller GPIO. IC Role / Device Role / Timing Role: Medium-current buffer amplifying logic-level signals to deliver ≥100 mA peak gate charge current. Use Value: High hFE (≥100 at 1A) ensures reliable saturation with modest MCU drive, reducing gate delay. | Use Scenario: Isolated control of 24V/1A industrial relays from PLC outputs or sensor interfaces. IC Role / Device Role / Timing Role: Final-stage power switch interfacing low-voltage logic to inductive relay coil loads. Use Value: BVCEO = 60 V and built-in ESD protection (HBM ≥8 kV) withstand relay flyback transients and noisy factory environments. |
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 (100 V), lower IC (0.5 A), SOT23 package | Better for higher-voltage, lower-current signal switching; unsuitable for 1A loads | Select when board space is constrained and voltage stress exceeds 60 V but current ≤500 mA. |
| MJD122G | Same SOT223 package, higher IC (2 A), lower fT (3 MHz), no AEC-Q101 | Higher current capacity but slower switching; not automotive-qualified | Prefer for non-automotive 2A switching where speed is secondary to current headroom. |
Compared with ZXTN25012E6TA and MJD122G, FZT491TA uniquely balances 1A current, 60V rating, 150 MHz fT, and AEC-Q101 qualification-making it optimal for automotive-grade medium-power switching where reliability, speed, and thermal performance intersect.
Availability
FZT491TA is available at Aetrix Electronics and suitable for automotive LED drivers, DC-DC converters, and MOSFET gate driving applications requiring stable component supply and long-term production continuity.
Supply support for FZT491TA 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 consumer markets.
FZT491TA belongs to Diodes' AEC-Q101-qualified medium-power transistor product line, designed specifically for robust switching in automotive body electronics and industrial power interfaces.
FAQ
What is the maximum allowable junction temperature for FZT491TA?
The FZT491TA has an operating junction temperature range of –55°C to +150°C. Its absolute maximum TJ is 150°C; sustained operation above this limit risks permanent degradation. Derating curves in the datasheet define safe power limits versus ambient temperature for both 25mm×25mm and 50mm×50mm PCB layouts.
Can FZT491TA replace a small-signal transistor like BC847 in a switching circuit?
No-FZT491TA is a medium-power device optimized for 1A loads and thermal dissipation, unlike BC847 (100mA IC). Substituting it in low-current signal paths adds unnecessary cost, size, and base drive requirements. Use only where ≥500mA continuous current or AEC-Q101 qualification is required.
Is the exposed collector tab electrically isolated from other pins?
No-the SOT223 collector tab is internally connected to the collector terminal (Pin 3). It must be treated as a live high-current node and thermally bonded to a PCB copper pour. Electrical isolation requires insulating thermal pads or dielectric coatings if mounted over internal ground planes.
Does FZT491TA support pulse operation beyond its DC ratings?
Yes-its peak pulse current ICM is 2A, and transient thermal impedance charts show safe single-pulse operation up to 10 ms at reduced duty cycles. Pulse width, duty cycle, and PCB thermal mass must be validated using the provided transient thermal curves to avoid junction overheating.
FZT491TA 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):
- 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:
- 2 W
- Frequency - Transition:
- 150MHz
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-223-3
FZT491TA FAQ
1.How can I place an order for FZT491TA through Aetrix?
Please submit a Request for Quotation (RFQ) for FZT491TA 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 FZT491TA reliable?
The price and inventory of FZT491TA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FZT491TA is usually 5 days.
3.What payment methods are accepted for FZT491TA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FZT491TA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for FZT491TA?
FZT491TA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your FZT491TA 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 FZT491TA?
For technical support, including FZT491TA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FZT491TA requirements.
6.How does Aetrix verify that FZT491TA is sourced from the original manufacturer or authorized distributors?
All FZT491TA 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 FZT491TA meets industry standards.
7.What is the process for return or replacement of FZT491TA?
All FZT491TA units undergo pre-shipment inspection (PSI). If there is an issue with FZT491TA, 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 FZT491TA part is unused and in its original packaging.
Return procedure for FZT491TA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
FZT491TA Tags
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