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Diodes Incorporated FZT657TC
- Part No.:
- FZT657TC
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Bipolar Transistors
- Package:
- TO-261-4, TO-261AA
- Datasheet:
-
FZT657TC.pdf
- Description:
- TRANS NPN 300V 0.5A SOT-223-3
- Quantity:
- Payment:
- Shipping:
Inventory:6,523
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Product details
Overview
FZT657TC from Diodes Incorporated is a 300V NPN high-voltage transistor in SOT223 package, designed for switching and linear amplification in high-voltage industrial power supplies and lighting ballasts. It delivers 0.5A continuous collector current, supports 1A peak pulse current, and features BVCEO and BVCBO ≥300V with hFE = 40–50 at IC = 10mA.
For engineers reviewing the FZT657TC datasheet, FZT657TC pinout, FZT657TC application, or FZT657TC equivalent, key selection criteria include high-voltage blocking capability (≥300V), thermal resistance (RθJA = 41.7°C/W on 50mm × 50mm 2oz copper), safe operating area robustness, and complementary PNP pairing with FZT757.
Technical Context
This NPN bipolar junction transistor operates in active, saturation, and cutoff regions with verified DC current gain (hFE) of 40–50 at VCE = 5V and IC = 10mA, and 30MHz fT under VCE = 20V, IC = 10mA conditions. Its high breakdown voltages enable use in flyback and forward converter primary-side switches.
Thermal performance is defined across four mounting configurations: RθJA ranges from 41.7°C/W (50mm × 50mm 2oz copper) to 104°C/W (minimum pad layout), with RθJL = 12.9°C/W confirming efficient heat conduction through the collector lead.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Collector-Emitter Voltage (VCEO) | 300 V - Enables operation in 230VAC mains-referenced circuits with safety margin. |
| Continuous Collector Current (IC) | 0.5 A - Supports medium-power switching up to ~15W at 30V VCE in linear mode. |
| DC Current Gain (hFE) | 40–50 @ IC = 10mA - Provides predictable base drive requirements for gate-driving or relay control. |
| Collector-Emitter Saturation Voltage (VCE(sat)) | ≤0.5 V @ IC = 100mA, IB = 10mA - Limits conduction loss to <50mW in saturated switching. |
| Transition Frequency (fT) | 30 MHz - Supports switching frequencies up to ~3–5 MHz in resonant or low-duty-cycle applications. |
| Thermal Resistance (RθJA) | 41.7 °C/W - Requires ≥50mm × 50mm 2oz copper pour for full 3W dissipation at +25°C ambient. |
| ESD Rating (HBM) | 4,000 V - Meets JEDEC Class 3A, enabling handling without special ESD controls in assembly. |
Pinout & Package
Package: SOT223 (Type DN), surface-mount, 4-pin configuration with emitter-connected tab (pin 3) acting as thermal and electrical ground reference. Molded plastic body meets UL 94V-0 flammability rating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (Emitter) | Emitter terminal | Primary current return path; electrically and thermally connected to exposed tab for heatsinking. |
| Pin 2 (Base) | Control input | Low-impedance input requiring ~10mA drive for full saturation at 100mA collector current. |
| Pin 3 (Collector / Tab) | Main power output | High-current output node; tab must be soldered to PCB copper for thermal management and voltage isolation compliance. |
| Pin 4 (Emitter) | Second emitter connection | Duplicate emitter terminal for improved current sharing and reduced bond-wire inductance in high-dI/dt switching. |
Key Features
| Feature | Design Value |
|---|---|
| 300V breakdown rating | Supports direct interface with 230VAC rectified rails without external snubbers in low-frequency switching. |
| SOT223 thermal performance | RθJL = 12.9°C/W enables >2W continuous dissipation with minimal PCB copper when collector tab is fully soldered. |
| Complementary PNP pairing | FZT757 shares identical voltage/current ratings and SOT223 footprint, simplifying push-pull and H-bridge design. |
| Lead-free & halogen-free construction | Meets RoHS 3 (2015/863/EU) and automotive "Green" standards (<900ppm Br/Cl, <1000ppm Sb), suitable for eco-sensitive OEMs. |
Applications
| Industrial Power Supplies | LED Driver Circuits |
|---|---|
Use Scenario: Primary-side switch in offline flyback converters delivering 10–25W output. IC Role / Device Role / Timing Role: High-voltage NPN switch controlling energy transfer during MOSFET-gated or self-oscillating operation. Use Value: 300V VCEO withstands reflected flyback spikes up to 280V, eliminating need for clamping diodes in cost-sensitive designs. |
Use Scenario: Constant-current linear regulator for high-brightness LED strings in streetlight modules. IC Role / Device Role / Timing Role: Series-pass transistor regulating current via analog feedback loop. Use Value: Low VCE(sat) ≤0.5V minimizes power loss at 350mA, improving thermal efficiency over TO-92 alternatives. |
| AC Motor Control | Ignition Systems |
Use Scenario: Phase-control dimmer for universal AC motors in HVAC blowers and pumps. IC Role / Device Role / Timing Role: Triggering TRIAC gate via zero-crossing synchronized pulses. Use Value: 1A ICM handles transient gate charge surges without secondary protection components. |
Use Scenario: Primary-side switch in capacitive discharge ignition (CDI) systems for small engines. IC Role / Device Role / Timing Role: Fast-switching transistor discharging storage capacitor into ignition coil primary. Use Value: 30MHz fT ensures sub-microsecond turn-off, enabling precise spark timing control at 10k RPM. |
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 |
|---|---|---|---|
| STN3HF30 | 300V VCEO, but MOSFET (N-channel); RDS(on) = 2.5Ω, no base drive required. | Replaces BJT with voltage-driven switch; eliminates base resistor network but requires higher gate voltage (>10V). | Select when gate drive circuitry exists and lower static power loss is prioritized over cost. |
| MJD122G | 200V VCEO, same SOT223 package; hFE = 30–120, higher gain variability. | Limited to ≤170V DC bus applications; unsuitable for 230VAC-derived rails without derating. | Acceptable only in legacy 115VAC-only designs where 300V margin is unnecessary. |
Compared with STN3HF30 and MJD122G, FZT657TC uniquely balances 300V ruggedness, predictable hFE, and SOT223 thermal performance-making it optimal for new 230VAC industrial switchers where BJT drive simplicity and voltage margin are critical.
Availability
FZT657TC is available at Aetrix Electronics and suitable for industrial power supplies, LED driver circuits, AC motor control, and ignition systems requiring stable component supply and long-term manufacturing continuity.
Supply support for FZT657TC 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.
FZT657TC belongs to Diodes' high-voltage bipolar transistor product line, engineered specifically for cost-sensitive, high-reliability industrial switching applications where voltage margin, thermal stability, and RoHS-compliant packaging are mandatory.
FAQ
What is the maximum safe operating temperature for FZT657TC?
The FZT657TC has an operating junction temperature range of –55°C to +150°C. At ambient temperatures above +70°C, derating is required per Figure 5: power dissipation drops linearly from 3W at +25°C to 0W at +150°C when mounted on 50mm × 50mm 2oz copper. Thermal shutdown is not built-in; external thermal monitoring is recommended for sustained high-temp operation.
Can FZT657TC replace a MOSFET in a flyback converter primary switch?
FZT657TC can replace low-frequency MOSFETs (<100kHz) in flyback converters where gate drive simplicity and cost outweigh switching loss concerns. Its 30MHz fT supports adequate turn-off speed, but VCE(sat) losses exceed typical MOSFET RDS(on) losses above 50kHz. Base drive must be actively clamped to avoid second breakdown during transients.
Is FZT657TC qualified for automotive applications?
The standard FZT657TC is not AEC-Q101 qualified. Diodes offers automotive-grade variants (e.g., FZT657Q) with PPAP documentation, IATF 16949 manufacturing, and extended temperature validation. These Q-suffix parts undergo additional reliability testing including HTGB, HTRB, and ESD qualification per AEC-Q101 Rev D.
How does the dual-emitter pin configuration improve performance?
The SOT223 package uses pins 1 and 4 as separate emitter connections to reduce bond-wire inductance and current-path resistance. This lowers VCE(sat) variance under pulsed loads and improves switching consistency in high-dI/dt applications like ignition coils, where simultaneous emitter current sharing prevents localized heating and gain shift.
FZT657TC 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):
- 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:
- 2 W
- Frequency - Transition:
- 30MHz
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-223-3
FZT657TC FAQ
1.How can I place an order for FZT657TC through Aetrix?
Please submit a Request for Quotation (RFQ) for FZT657TC 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 FZT657TC reliable?
The price and inventory of FZT657TC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FZT657TC is usually 5 days.
3.What payment methods are accepted for FZT657TC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FZT657TC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for FZT657TC?
FZT657TC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your FZT657TC 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 FZT657TC?
For technical support, including FZT657TC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FZT657TC requirements.
6.How does Aetrix verify that FZT657TC is sourced from the original manufacturer or authorized distributors?
All FZT657TC 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 FZT657TC meets industry standards.
7.What is the process for return or replacement of FZT657TC?
All FZT657TC units undergo pre-shipment inspection (PSI). If there is an issue with FZT657TC, 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 FZT657TC part is unused and in its original packaging.
Return procedure for FZT657TC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
FZT657TC Tags
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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