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Diodes Incorporated FZT657QTA
- Part No.:
- FZT657QTA
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Bipolar Transistors
- Package:
- TO-261-4, TO-261AA
- Datasheet:
-
FZT657QTA.pdf
- Description:
- TRANS NPN 300V 0.5A SOT-223-3
- Quantity:
- Payment:
- Shipping:
Inventory:965
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Product details
Overview
FZT657QTA from Diodes Incorporated is a 300V NPN high-voltage transistor in SOT223 package, rated for 0.5A continuous collector current and 1A peak pulse current, with BVCEO ≥ 300V and VCE(sat) ≤ 0.5V at IC = 100mA/IB = 10mA, used in flyback snubber circuits and industrial power supply switching stages.
For engineers reviewing the FZT657QTA datasheet, FZT657QTA pinout, FZT657QTA application, or FZT657QTA equivalent, key selection criteria include high-voltage blocking capability (300V), thermal resistance to ambient (41.7°C/W on 50mm × 50mm 2oz copper), DC current gain (hFE = 40–50 at IC = 10mA), safe operating area robustness, and RoHS-compliant green packaging.
Technical Context
This NPN bipolar junction transistor operates in linear and switching modes with verified breakdown voltages of VCBO ≥ 300V and VCEO ≥ 300V, enabling use in high-side switch configurations where collector voltage swings exceed 250V. Its fT = 30MHz supports moderate-speed switching in offline SMPS auxiliary supplies.
Thermal performance is defined across four mounting conditions: RθJA ranges from 41.7°C/W (50mm × 50mm 2oz copper) to 104°C/W (minimum pad layout), and RθJL = 12.9°C/W confirms effective heat conduction through the collector lead-critical for sustained 3W dissipation in open-frame industrial designs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 300 V - Enables direct replacement of legacy 250V transistors in AC-DC front-end snubbers without derating. |
| IC (cont.) | 0.5 A - Supports continuous operation in low-power auxiliary rails up to 15W with forced-air cooling. |
| VCE(sat) | ≤ 0.5 V @ IC=100mA/IB=10mA - Limits conduction loss to <50mW in saturated switching applications. |
| hFE | 40–50 @ IC=10mA/VCE=5V - Ensures stable base drive design with minimal margin required for β variation. |
| fT | 30 MHz - Allows reliable operation up to ~500kHz switching frequency in resonant converters. |
| RθJA | 41.7 °C/W (50mm×50mm 2oz Cu) - Defines minimum PCB copper area needed to maintain TJ < 125°C at full 3W dissipation. |
| ESD HBM | 4,000 V - Meets JEDEC Class 3A, supporting handling in non-ESD-controlled assembly environments. |
Pinout & Package
Package: SOT223 (Type DN), molded plastic with matte tin-plated leads, UL 94V-0 rating, 0.112g weight, moisture sensitivity level 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Collector (C) | Main current-carrying terminal | Large metal tab connected to internal die collector; primary thermal path to PCB copper pour. |
| Emitter (E) | Current return path | Electrically isolated from tab; requires low-inductance routing to minimize switching overshoot. |
| Base (B) | Control input | High-impedance gate-equivalent node requiring current-limited drive to avoid saturation delay. |
Key Features
| Feature | Design Value |
|---|---|
| 300V breakdown rating | Enables direct integration into 230VAC line-referenced circuits without external voltage clamping. |
| SOT223 thermal performance | Delivers 3W power dissipation capability with standard FR-4 PCB layout-no heatsink required below 15W output. |
| Complementary PNP pairing | FZT757 provides matched VCEO, IC, and hFE for push-pull or H-bridge driver stages. |
| Halogen- and antimony-free "Green" construction | Meets automotive and industrial environmental compliance mandates without sacrificing thermal or electrical performance. |
Applications
| Industrial Flyback Snubber | AC-DC Auxiliary Supply |
|---|---|
Use Scenario: Clamps voltage spikes during MOSFET turn-off in 20–50W offline flyback converters. IC Role / Device Role / Timing Role: High-voltage NPN switch absorbing energy from transformer leakage inductance. Use Value: Eliminates need for TVS diode by sustaining 300V repetitive transients with <0.5V saturation drop. |
Use Scenario: Provides regulated +12V/100mA bias supply for main PWM controller in industrial SMPS. IC Role / Device Role / Timing Role: Linear pass transistor in simple series-regulated auxiliary rail. Use Value: Maintains regulation under 0.5A load with <1.5°C/W junction-to-lead thermal resistance. |
| LED Driver Pre-regulator | Isolated Gate Drive Coupling |
Use Scenario: Pre-regulates bulk DC before buck converter stage in outdoor LED streetlight drivers. IC Role / Device Role / Timing Role: High-voltage series pass element controlling input to downstream DC-DC stage. Use Value: Handles 277VAC-derived 380VDC bus with 300V VCEO margin and 41.7°C/W thermal resistance. |
Use Scenario: Level-shifts and amplifies gate drive signals across isolation barriers in IGBT modules. IC Role / Device Role / Timing Role: Fast-switching NPN buffer driving isolated gate transformer primary. Use Value: 30MHz fT ensures sub-100ns propagation delay with 1A peak current capability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-voltage NPN transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ZTX653 | VCEO = 250V, hFE = 100–300, SOT89 package | Lacks 300V margin; requires derating in 230VAC systems; higher gain reduces base drive stability. | Select only when lower voltage stress and tighter hFE tolerance are acceptable. |
| MJD127 | VCEO = 100V, IC = 2A, TO-220 package | Inadequate voltage rating for primary-side snubbing; larger footprint increases layout complexity. | Use only in low-voltage secondary-side switching where thermal mass outweighs voltage needs. |
Compared with ZTX653 and MJD127, FZT657QTA uniquely balances 300V blocking, SOT223 thermal efficiency, and predictable hFE for cost-sensitive industrial power stages where voltage margin and board space are critical constraints.
Availability
FZT657QTA is available at Aetrix Electronics and suitable for industrial power supplies, LED driver pre-regulators, and isolated gate drive coupling requiring stable component supply, long-term lifecycle support, and RoHS-compliant green manufacturing.
Supply support for FZT657QTA 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 ISO/TS 16949-certified manufacturing facilities and broad distribution networks.
FZT657QTA belongs to Diodes' high-voltage bipolar transistor product line, engineered specifically for reliability-critical industrial and automotive auxiliary power applications demanding >300V breakdown and JEDEC-qualified robustness.
FAQ
What is the maximum allowable junction temperature for FZT657QTA?
The absolute maximum junction temperature is +150°C, and the device is rated for continuous operation across –55°C to +150°C storage and operating ranges. Derating begins at +25°C ambient per Figure 5: at +100°C ambient, maximum power dissipation drops to 1.2W on minimum pad layout.
Can FZT657QTA replace FZT651 in existing designs?
No-FZT651 has VCEO = 200V and IC = 0.3A, making it unsuitable for direct substitution. FZT657QTA's 300V rating and 0.5A current capability provide 50% higher voltage margin and 67% higher current, requiring verification of base drive strength and PCB thermal relief.
Does FZT657QTA meet AEC-Q101 requirements?
FZT657QTA is not automotive-qualified; Diodes offers the AEC-Q101-compliant FZT657QTA-Q variant with PPAP documentation, IATF 16949 manufacturing, and extended temperature validation. The standard part meets JEDEC high-reliability standards but lacks automotive change control.
How does the SOT223 package affect thermal performance in confined layouts?
On minimum recommended pad layout, RθJA rises to 104°C/W-limiting usable power to ~1.2W at +70°C ambient. To sustain 3W, the collector tab must connect to ≥50mm × 50mm 2oz copper; thermal vias under the tab further reduce RθJA by ~15% in multilayer boards.
FZT657QTA 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):
- 500 mA
- Voltage - Collector Emitter Breakdown (Max):
- 300 V
- Vce Saturation (Max) @ Ib, Ic:
- 500mV @ 10mA, 100mA
- Current - Collector Cutoff (Max):
- 100nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 50 @ 100mA, 5V
- Power - Max:
- 3 W
- Frequency - Transition:
- 30MHz
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-223-3
FZT657QTA FAQ
1.How can I place an order for FZT657QTA through Aetrix?
Please submit a Request for Quotation (RFQ) for FZT657QTA 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 FZT657QTA reliable?
The price and inventory of FZT657QTA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FZT657QTA is usually 5 days.
3.What payment methods are accepted for FZT657QTA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FZT657QTA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for FZT657QTA?
FZT657QTA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your FZT657QTA 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 FZT657QTA?
For technical support, including FZT657QTA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FZT657QTA requirements.
6.How does Aetrix verify that FZT657QTA is sourced from the original manufacturer or authorized distributors?
All FZT657QTA 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 FZT657QTA meets industry standards.
7.What is the process for return or replacement of FZT657QTA?
All FZT657QTA units undergo pre-shipment inspection (PSI). If there is an issue with FZT657QTA, 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 FZT657QTA part is unused and in its original packaging.
Return procedure for FZT657QTA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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