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Diodes Incorporated FZT491TC
- Part No.:
- FZT491TC
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Bipolar Transistors
- Package:
- TO-261-4, TO-261AA
- Datasheet:
-
FZT491TC.pdf
- Description:
- TRANS NPN 60V 1A SOT-223-3
- Quantity:
- Payment:
- Shipping:
Inventory:2,468
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Product details
Overview
FZT491TC 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/100mA drive, and qualified to AEC-Q101 for automotive-grade reliability; it serves as a robust switch in power MOSFET gate driving and low-loss DC-DC converter output stages.
For engineers reviewing the FZT491TC datasheet, FZT491TC pinout, FZT491TC application, or FZT491TC equivalent, key selection criteria include its 60V VCEO, 1A IC, low saturation voltage under high-current switching, thermal resistance of 41.7°C/W on 50mm×50mm 2oz copper, and AEC-Q101 qualification for harsh-environment automotive and industrial control designs.
Technical Context
The FZT491TC operates as a silicon NPN bipolar junction transistor optimized for medium-power linear and switching applications. Its design supports stable DC current gain (hFE = 80–300 across 1mA–2A) and high-frequency response (fT = 150 MHz), enabling use in fast-switching gate drivers and regulated power supply feedback paths.
Thermal performance is defined by two mounting conditions: RθJA = 62.5°C/W on 25mm×25mm 1oz FR4 and 41.7°C/W on 50mm×50mm 2oz FR4. Junction-to-lead thermal resistance is 19.41°C/W, supporting direct heat conduction through the collector lead in thermally constrained layouts.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 60 V - Maximum safe collector-emitter voltage before breakdown; enables use in 48V automotive and industrial bus interfaces. |
| IC (continuous) | 1 A - Sustained collector current rating; supports medium-power load switching without forced cooling. |
| VCE(sat) | ≤500 mV @ 1A/100mA - Low saturation voltage minimizes conduction loss and self-heating in high-duty-cycle switching. |
| hFE | 80–300 - Wide DC current gain range ensures reliable base drive margin across production lots and temperature extremes. |
| fT | 150 MHz - Transition frequency supports gate driving of MOSFETs up to ~200 kHz PWM with minimal phase lag. |
| RθJL | 19.41 °C/W - Low junction-to-lead thermal resistance allows effective heat transfer via collector pad to PCB copper. |
Pinout & Package
Package: SOT223 - Surface-mount plastic package with exposed collector tab for thermal and electrical connection; 0.112 g mass; UL 94V-0 flammability rating; moisture sensitivity level 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Collector (C) | Main current-carrying terminal, electrically connected to exposed tab | Primary heat path to PCB; must be soldered to large copper area for thermal management. |
| Emitter (E) | Current return path; common reference for base drive | Low-impedance return node; layout should minimize inductance for fast switching. |
| Base (B) | Control input for bipolar current amplification | Requires current-limited drive (max 200 mA); sensitive to ESD (HBM ≥8 kV). |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive underhood applications including temperature cycling, humidity bias, and mechanical shock. |
| Low VCE(sat) at 1A | Reduces power dissipation to ≤0.5 W during saturation, easing thermal design in space-constrained modules. |
| Complementary PNP pair (FZT591) | Enables matched push-pull output stages with consistent gain and thermal tracking. |
| Halogen- and antimony-free "Green" construction | Meets IEC 61249-2-21 requirements with <900 ppm Br/Cl and <1000 ppm Sb; supports eco-compliant manufacturing. |
Applications
| Automotive Door Module | Industrial PLC Output Stage |
|---|---|
Use Scenario: Driving window lift motors and mirror actuators in 12V/24V vehicle subsystems. IC Role / Device Role / Timing Role: Medium-power NPN switch controlling motor direction and braking via H-bridge half-bridge configuration. Use Value: 60V VCEO withstands load-dump transients; AEC-Q101 qualification ensures operation from –40°C to +125°C ambient. | Use Scenario: Switching 24V DC solenoids and indicator lamps in programmable logic controller output cards. IC Role / Device Role / Timing Role: Discrete power switch interfacing microcontroller GPIO to inductive loads with flyback protection. Use Value: 1A IC and low VCE(sat) enable direct drive without external driver ICs, reducing BOM count and board area. |
| DC-DC Converter Gate Driver | LED Constant-Current Regulator |
Use Scenario: Providing high-current base drive to power MOSFETs in synchronous buck converter top-side switches. IC Role / Device Role / Timing Role: Fast-turn-on NPN buffer amplifying PWM controller output to reduce MOSFET gate charge time. Use Value: 150 MHz fT and low VBE(sat) ensure sub-100 ns turn-on delay, minimizing shoot-through risk. | Use Scenario: Regulating current through high-brightness LED strings in signage and architectural lighting. IC Role / Device Role / Timing Role: Linear pass transistor in constant-current sink configuration with op-amp feedback. Use Value: Stable hFE over temperature and low VCE(sat) maintain tight current regulation while dissipating <0.3 W at 350 mA. |
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 |
|---|---|---|---|
| ZXTN25040DFHTA | Higher VCEO (100 V), lower IC (0.5 A), SOT23 package, RθJA = 250°C/W | Better voltage margin but limited current and thermal capability; unsuitable for >500 mA continuous loads. | Select when voltage headroom is critical and power dissipation is low; avoid for 1A switching. |
| MJD122G | Same SOT223 package, higher IC (2 A), higher VCE(sat) (1.2 V @ 2A), no AEC-Q101 qualification | Higher current capacity but reduced efficiency and unqualified for automotive use. | Prefer for non-automotive 2A applications where thermal budget allows higher VCE(sat). |
Compared with ZXTN25040DFHTA and MJD122G, the FZT491TC uniquely balances 1A current, 60V rating, low saturation voltage, and AEC-Q101 compliance-making it optimal for thermally constrained automotive and industrial switching where reliability and efficiency intersect.
Availability
FZT491TC is available at Aetrix Electronics and suitable for automotive door modules, industrial PLC output stages, DC-DC converter gate drivers, and LED constant-current regulators requiring stable component supply and long-term lifecycle support.
Supply support for FZT491TC 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, headquartered in Plano, Texas, with design and manufacturing operations across Asia and the Americas.
The FZT491TC belongs to Diodes' AEC-Q101-qualified medium-power transistor product line, engineered for robust switching and linear regulation in automotive body electronics and industrial control systems.
FAQ
What is the maximum allowable junction temperature for FZT491TC?
The FZT491TC 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 based on ambient temperature and PCB copper area.
Is FZT491TC pin-compatible with FZT591?
No-FZT491TC (NPN) and FZT591 (PNP) share the same SOT223 package and pinout order (C-E-B), but their complementary polarity means they cannot substitute directly. They are designed for coordinated use in push-pull or H-bridge circuits, not interchangeably.
Does FZT491TC require a base resistor in all applications?
Yes-base current must be externally limited to prevent damage. With IB(max) = 200 mA and typical hFE ≥ 80 at 1A IC, a minimum base drive of 12.5 mA is required; a series resistor sized for the driving voltage and desired IB is mandatory for reliable operation.
Can FZT491TC be used in linear regulator applications?
Yes-it is specified for linear operation with stable hFE and low VCE(sat). In emitter-follower or series-pass configurations, it delivers predictable current gain and thermal behavior, provided junction temperature remains within –55°C to +150°C and power dissipation stays within derated limits.
FZT491TC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- TO-261-4, TO-261AA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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
FZT491TC FAQ
1.How can I place an order for FZT491TC through Aetrix?
Please submit a Request for Quotation (RFQ) for FZT491TC 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 FZT491TC reliable?
The price and inventory of FZT491TC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FZT491TC is usually 5 days.
3.What payment methods are accepted for FZT491TC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FZT491TC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for FZT491TC?
FZT491TC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your FZT491TC 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 FZT491TC?
For technical support, including FZT491TC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FZT491TC requirements.
6.How does Aetrix verify that FZT491TC is sourced from the original manufacturer or authorized distributors?
All FZT491TC 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 FZT491TC meets industry standards.
7.What is the process for return or replacement of FZT491TC?
All FZT491TC units undergo pre-shipment inspection (PSI). If there is an issue with FZT491TC, 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 FZT491TC part is unused and in its original packaging.
Return procedure for FZT491TC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
FZT491TC Tags
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